Appendix J Wildlife Reports
To: Linda Cope, Wyoming Game and Fish Department
From: Kim Chapman & Genesis Mickel, Applied Ecological Services
Date: June 14, 2017
Re: Memo on new surveys requested by Wyoming Game & Fish Department ______
AES biologists have been collecting baseline biological data and recording incidental observations for the Boswell Springs Wind Project between 2011 and 2016 in consultation with Wyoming Game and Fish Department (WGFD) and U.S. Fish and Wildlife Service (USFWS). During a Project meeting on May 26, 2017 and follow-up letter dated June 5, 2017, staff at the WGFD requested targeted surveys for four species of interest to better assess their presence or absence in the Project area. The four species are black-footed ferret, swift fox, mountain plover, and long-billed curlew. The purpose of this memo is to summarize the survey methodology presented and accepted by WGFD on a June 12, 2017 conference call.
1. White-tailed prairie dog activity areas. Incidental sightings or evidence for black-footed ferret, swift fox, and mountain plover, have been isolated to areas identified as high-density for prairie dog burrows. As a result, the first task is to refine the mapping of the prairie dog colonies and field verify the high- activity areas. The resulting high-activity areas will then be used to survey for presence or absence of these species.
Prairie dog burrow densities were originally mapped in the Project area from aerial photos, which were then ground-truthed along transects. The resulting map indicated areas of burrows at high, moderate, and low densities, but did not pinpoint the areas where prairie dogs were most active. In all but one of the areas mapped as high-density burrow areas, we have observed subareas of higher prairie dog activity. We have seen little to no activity in areas mapped as moderate- and low-density for burrows.
We propose conducting an additional field visit to survey all previously mapped high-density burrow areas to observe prairie dogs at a distance and map where they are active. These observations will then be used to revise the original boundaries delineating the high-density areas and identify the high-activity areas. High-density areas with little to no activity will be retained in the GIS output, but reclassified to distinguish from areas with field-verified high-activity.
Based on past field experience in the area over the last two years, the high-activity areas are expected to be nearly entirely located inside the previously mapped high-density burrow areas. High-density burrow areas are oriented east to west across the site, on level ground to the north and south of the main stream system. In addition, an area south of the southern line of high-density burrows may also be a high-activity prairie dog area. The boundaries of high-activity areas will be mapped and used in
conducting the surveys for black-footed ferret, swift fox, and mountain plover. It is anticipated that the acreage of high-activity prairie dog areas will be about 3,000 acres.
2. Black-footed ferret. Black footed-ferret (BFF) diggings were discovered in the southwest corner of the permit area on Dec. 8, 2016. No sign was discovered during subsequent winter surveys, but conditions were less suitable than at other visits due to the lack of new snow and strong winds.
Night-time spotlighting for BFF will be conducted in areas field-verified as high-activity prairie dog areas, following the protocol of the WGFD “Handbook of Biological Techniques” (August 2007, revised 2013). The acreage covered by each survey session will depend on the boundaries of the high-activity areas and the topography along the survey route. Each spotlighting session will take place over three consecutive nights, spanning nearly the entire night, and cover about 600 acres each. Five spotlighting sessions of three consecutive nights each are expected to cover the 3,000 anticipated acres of high-activity prairie dog areas. If the high-activity areas cover much more than 3,000 acres, an additional survey session will be carried out. The surveys will be completed between late July and the end of September.
3. Swift fox. Swift foxes are known to inhabit and den within the site. The “Handbook of Biological Techniques”, states that spotlight surveying is an effective method for detecting individuals and dens in locations where swift fox are known or suspected to occur. Since it is already known that swift fox are present, spotlight surveys should be used instead of cameras to determine individual denning sites.
At Boswell Springs, swift fox have always been observed in the high-density burrow areas, which overlap the preferred habitat of the black-footed ferret. Fox surveys will be conducted for four hours beginning at dusk and for three consecutive nights, on two occasions. This survey period coincides with and will be conducted at the same time as the ferret spotlighting surveys. The two species are distinguishable by the color of their eye shine.
4. Mountain plover. Mountain plover has been observed on the site during the breeding season, but no nests have been located. Of the five mountain plover sightings in the 2011-2016 period, two were during the migration period (April), two during the egg incubation period (May 20-June 7), and one during the chick-rearing period (June 20-July 7).
Suitable habitat is primarily in areas with prairie dog high-density burrows and high-activity. Surveys will be conducted following WGFD protocol. This involves driving a survey route, stopping the vehicle, walking around the vehicle at a distance of 20 feet, then getting back into the vehicle and scanning at a distance in all directions around the vehicle for 3 minutes. If a plover is present, it will be flushed from its nest by the walking surveyor, then return to the nest after the surveyor gets back in the vehicle as plovers do not flush at moving vehicles. Chicks are also highly visible in the latter survey period. The protocol does not specify a distance between each survey point; we will place points 400 meters apart in suitable habitat, making the scanned area around vehicles approximately 200 meters. Surveys for the chick-rearing period must be complete by July 7. Because two raptor surveys are already scheduled for late June and early July, it will be possible to conduct two mountain plover surveys in the chick-rearing period. These will be completed on the same site visits as raptor surveys, but be conducted at a different time than and separate from the raptor surveys.
5. Long Billed Curlew. Long-billed curlew had been observed (or potential evidence observed) incidentally by AES biologists between 2011 and 2016. After additional discussion via teleconference and confirmed via e-mail dated June 12, 2017, WGFD agreed that no surveys for curlew were needed as
Boswell Springs Additional Surveys 2017 (AES 15-0285) 2 evidence was limited to only a single observation in the early April migration period in 2016 despite extensive, multi-year avian point count surveys conducted at the site.
Boswell Springs Additional Surveys 2017 (AES 15-0285) 3
1116 Albin St. (307) 742-3506 Laramie, WY 82072 Email: [email protected] www.realwestconsulting.com
DATE: Original: January 5, 2016 Update: February 1, 2017
PREPARED BY: Amber Travsky Real West Natural Resource Consulting 1116 Albin St. Laramie, WY 82072
PREPARED FOR: Kim Chapman and Genesis Mickel Applied Ecological Services 21938 Mushtown Road Prior Lake, MN 55372
SUBJECT: Boswell Springs Wind Farm Incidental Observations
DISCUSSION: Incidental observations of wildlife were noted during all visits to the project area from 2010 through 2016. Incidental observation occurred both outside and within the times and locations for scheduled quantitative surveys. The results are presented below.
Amphibian and Reptiles Observations of suitable habitat for amphibians were made by walking wetland perimeters, conducting flushing surveys of emergent vegetation and occasionally dip-netting the open water and submerged vegetation. Reptile surveys consisted of searching rock outcrop areas and making general observations while traversing the site for other surveys.
There are nine ponds and wetland areas within the permit area, as identified in the 2011 site report (AES 2011)1. Of these, sites A3 and A7 are the same reservoir. Site A2 is a borrow ditch that typically creates a small pond/wetland area that holds water well into the late summer. The sites are identified on the map presented at the end of this report (Figure A). This map was used
1 Applied Ecological Services (AES). 2011. Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm. Prepared for Paul Martin, Intermountain Wind, Boulder, CO. REAL WEST Page 2 ______
for the site report in 2011 and the site identifiers are the same as those used in the previous surveys.
The results of the surveys are presented in Table 1. Boreal chorus frogs were plentiful and common on the permit area. In addition to the perennial water sources listed, boreal chorus frogs were also found in areas of temporary ponding and even in borrow ditches that retained water into the spring. No additional dip netting was conducted in 2016 although the ponds were occasionally visited and the shorelines walked. No additional species were observed while boreal chorus frogs were either seen or heard at all listed locations.
Two reptile species were observed on the site: a prairie rattlesnake (Crotalus viridis) observed by Tim Banks on 09/01/2015 and a greater short-horned lizard (Phrynosoma hernandesi) observed by Amber Travsky on 07/13/2016.
Table 1. Results of surveys of wetland ponds and stream within the permit area.
Site Date ID Mode Location Results1 Chorus frogs 7/26/2015 A1 flushing/wading playa pond heard Chorus frogs A2 flushing/wading Borrow ditch heard Chorus frogs 8/11/2015 A3 flushing/wading/dip netting Reservoir heard Chorus frogs 8/29/2015 A4 flushing/wading Creek/pond heard Chorus frogs 8/29/2015 A5 flushing/wading Creek/pond heard Chorus frogs 8/29/2015 A6 flushing/wading Creek/pond heard Same site Chorus frogs as A3 A7 -- Reservoir heard Chorus frogs 8/11/2015 A8 flushing/wading Reservoir heard Chorus frogs 8/29/2015 A9 flushing/wading/dip netting Creek/pond heard 1The ponds and streams were not dip netted in 2016 but the sites were visited occasionally and the perimeters walked. No new species were observed in 2016 while chorus frogs were observed or heard at all sites.
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Mountain Plover No mountain plovers were observed during the 2015 surveys but there were three incidental observations reported by A. Travsky in 2016 and one observation by T. Banks in 2016. The 2016 observations are shown in the aerial map in Figure C at the end of this report.
Initially, two mountain plovers were observed on April 29, 2011 near the southwest corner of the permit area. The birds were observed only the one time that year although the area where they were seen was re-visited by surveyors numerous times. It is expected the birds were migrating through at the time and did not nest on the site.
A mountain plover was observed on a prairie dog town near Observation Point 30 on April 23, 2016. Due to the early timing, it was likely the plover was migrating through the area.
A mountain plover was observed within a prairie dog town near Observation Point 24 on two occasions in 2016. The timing of the observations (May 21 and June 10) indicates there is a high possibility of nesting at the location. Another 2016 observation was made by T. Banks on June 30 approximately 100 meters north of Observation Point 16. The timing of this observation also indicated the bird was likely nesting near the location.
Greater Sage-grouse Searches to locate any previously undocumented sage-grouse leks were conducted in 2009 and 2015 by A. Travsky. The permit area and, where access was possible, a two-mile buffer was surveyed on three occasions each year following WGFD protocol. No sage-grouse were observed during any of the surveys.
One sage-grouse hen was observed by A. Travsky on September 7, 2016. The location is shown in Figure C at the end of this report and is in the area of densest sagebrush on the permit area. Follow-up pedestrian surveys in the vicinity to flush addition sage-grouse or observe sage-grouse sign were conducted on numerous occasions through early November 2016. No additional sage- grouse or scat was observed.
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In addition to the surveys already described, pedestrian surveys were conducted throughout the surveys sessions. No sage-grouse sign was found elsewhere on the permit area, indicating the likelihood of any extensive use of the area by this species is unlikely.
White-tailed Prairie Dogs As reported in 2011, white-tailed prairie dogs are plentiful across the area. In 2010, belt transects were used for burrow counts. In 2015 and 2016, burrow density was not surveyed but the occurrence of prairie dogs was noted across the site. Based on ocular observations, burrow densities have changed only slightly since 2010. Changes are noted in the attached map at the end of this report (Figure B) with the changes in blue.
In 2016, prairie dogs were first reported active on March 25, 2016 and they remained active through October 2, 2016.
Preble’s jumping mouse Suitable Preble’s meadow jumping mouse habitat, which consists primarily of dense shrub habitat near open water, is absent on the permit area. This species is not expected to occur in the area.
Late Ute ladies’- tresses During the amphibian flushing surveys around wetland areas and ponds, searches for this threatened orchid were conducted during the flowering season, but no Ute ladies’-tresses were found.
Colorado butterfly plant During the amphibian flushing surveys around wetland areas and ponds, searches for this threatened plant species were conducted during the flowering season, but none were found.
Black-footed ferret Fresh diggings, identified as those likely made by black-footed ferrets, were observed by A. Travsky on 12/08/2016. The location is shown on the aerial photograph in Figure C at the end of this report. The sign included two primary burrow entrances that were interconnected
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underground with four smaller burrows. The prints were the distinct "twin print" of mustelids where the hind foot lands on top of the print from the front paw. Measured as the two prints together, the print is about 7.0 cm long and about 5.5 cm wide. Stride length was about 16 to 19 cm. That is in keeping with the stride of a walking ferret, but not a running one. Size of the prints is within the range of a ferret, if a bit on the small side. The diggings featured the long trench-like furrows, characteristic of black-footed ferrets, with two multi-lobbed burrows and four single-line burrows.
A spotlighting survey, conducted in summer of 2017, would be required to verify the presence of black-footed ferrets. This species is considered “Experimental Non-essential” in Albany County and does not require federal protection under the Endangered Species Act.
Pronghorn Pronghorn numbers were recorded on 17 observation points by A. Travsky for all of 2016, as shown in the graph in Figure 1. Note that the numbers include those observed from eagle activity survey observation points and within the observation circle. However, it is likely that some pronghorn were counted more than once due to their movement away from the observer and into adjacent observation circles. The pronghorn on the site are particularly skittish and are quick to run away from any human presence. The numbers, which cover slightly more than half of the permit area, are meant to be ballpark numbers to provide insight into the seasonal use by pronghorn.
In 2016, the first pronghorn of the year was observed on February 26, 2016. Pronghorn numbers gradually increased through the spring and summer, reaching a peak in late October. Numerous newborn fawns were observed in the spring, verifying the permit area as a pronghorn parturition area. In the fall, pronghorn tended to congregate in larger groups and then, during and following the first significant snowfall storm in late November, pronghorn migrated off the site. The migration was quick and sudden with groups observed moving to the northwest in long, single- file lines. By early December, no pronghorn were observed. REAL WEST Page 6 ______
Figure 1. Pronghorn observed by A. Travsky from 17 of the 30 observation points in 2016.
Pronghorn No. 500 450 400 350 300 250 200 150 100 50 0
Late Jan Late Late Oct Late Late Apr Late Feb Late July Late Dec Late Aug Early Jan Early Late Nov Late Late Mar Late Early Oct Early Apr Early Early Feb Late May Late Early July Early Dec Late Sept Early Aug Early Late June Late Early NovEarly Early May Early Early Sept Early Early June Early
Month
Other Wildlife Elk have been observed on the site four times: once in 2010, once in 2011, once in 2015 and again in January 2016. It is expected the elk wandered onto the site from the forest habitat northeast of the permit area. A small herd of 6 to 8 bull elk were observed on two occasions in the northeast corner of the permit area and it is possible this small herd stays in the area through the winter. In 2011, two bull elk were observed near the center of the permit area in early June. While elk may wander across the site, their numbers are quite low. No more than 8 elk have been seen on the permit area at one time.
Coyotes are year-round residents on the permit area with individuals being sighted during all survey sessions. Swift fox are less common but are observed regularly. Dens have been located for both species.
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Badgers are also common on the project site, being observed from spring through fall before the animals remain underground through the winter. Additional incidental wildlife observations by Amber Travsky and Tim Banks are provided at the end of this report. New species for 2016 include the greater sage-grouse, least weasel, thirteen-lined ground squirrel, and long-billed curlews.
Figure A. Amphibian survey locations. Figure B. White-tailed prairie dog burrow density. Figure C. Locations of mountain plovers, sage-grouse and black-footed ferret sign reported in 2016. Map shows the western half of the site. Incidental Observation by A. Travsky Date Species No. Easting Northing Comments
7/9/15 BAEA 2 442938 4640649 Perched on fence post near Wheatland Res #3 7/24/15 AMKE 2 438223 4642370 In cottonwood tree
7/24/15 NOHA 1 437897 4641989 flying
7/26/15 Badger 1 426794 4639630
7/26/15 NOHA 1 435760 4639663 flying
7/26/15 GOEA 1 431779 4640183 On windmill
7/28/15 Badger 1 426330 4639163
7/29/15 NOHA 1 431015 4640746 flying
7/29/15 Swift Fox 3 434876 4639578 Den site with 3 young seen 8/11/15 GOEA 1 431779 4640183 On windmill
8/11/15 NOHA 1 431015 4640746 flying
8/11/15 Coyote 1 427340 4639290
8/12/15 GOEA 1 429850 4640712 flying
8/29/15 TUVU 1 432120 4641465 flying
8/29/15 NOHA 1 431882 4641758 flying
8/29/15 Badger 1 432950 4641641
8/29/15 Coyote 2 437004 4641992
9/25/15 Badger 1 429684 4637822
9/25/15 Coyote 1 428334 4639345 feeding on pronghorn carcass 9/25/15 GOEA 1 431779 4640183 On windmill
10/10/15 Badger 1 426966 4643250
10/11/15 FEHA 2 437583 4638128 sitting on two different fence posts 10/23/15 GOEA 1 431806 4638929 on post
10/23/15 GOEA 1 431779 4640183 On windmill
11/7/15 Elk 6 437269 4643844 6 bulls bedded down on hillside 11/22/15 GOEA 1 437786 4640165 1/3/2016 Coyote 1 41.922396 105.811032
1/2/2016 jackrabbit 1 41.935686 105.852178
1/2/2016 Coyote 1 41.902887 105.853623
1/3/2016 GOEA 1 41.915585 105.833112 On metal fence
1/27/2016 GOEA 1 41.911788 105.745471 On post
1/27/2016 Coyote 1 41.932095 105.803904
1/27/2016 Coyote 1 41.928202 105.824788
2/9/2016 Coyote 1 41.900139 105.88802
2/25/2016 GOEA 1 41.911788 105.745471 On post
2/25/2016 Coyote 1 41.932273 105.865093
2/26/2016 Coyote 2 41.894159 105.86477
2/25/2016 RLHA 1 41.915877 105.789274
2/25/2016 Coyote 1 41.932186 105.79641
3/25/2016 Canada geese 60 41.908038 105.748995
3/25/2016 FEHA 1 41.931402 105.745189 in trees near nest site 3/25/2016 RLHA 1 41.907458 105.76934 On fence post
3/25/2016 Badger 1 41.932804 105.789628
3/27/2016 Badger 1 41.904227 105.775839
3/17/2016 Coyote 1 41.910853 105.890979
4/8/2016 GOEA 1 41.922812 105.747120 Perched on ground
4/8/2016 Long-billed curlews 7 41.905626 105.775448
4/8/2016 waterfowl on pond: killdeer; 41.901881 105.88089 greater yellowlegs 4/23/2016 Mountain plover 1 41.907755 105.889994
4/23/2016 waterfowl on pond: Horned 41.901881 105.88089 grebe, mallard, avocet, green- winged teal, Canada geese, pintail, lesser scaup, killdeer 4/23/2016 boreal chorus frogs 41.924413 105.86994
5/5/2016 AMKE 1 41.912941 105.876569 On fence wire 5/5/2016 boreal chorus frogs 41.886938 105.872736
5/5/2016 boreal chorus frogs 41.928006 105.870485
5/5/2016 say's phoebe 41.943581 105.893858
5/5/2016 Loggerhead shrike 41.942708 105.895593
5/5/2016 boreal chorus frogs 41.923752 105.891206
5/5/2016 boreal chorus frogs 41.907344 105.88811
5/5/2016 waterfowl on pond : horned 41.901881 105.88089 grebe, Wilson’s phalarope, lesser scaup, redhead, mallard, widgeon 5/5/2016 boreal chorus frogs 41.887266 105.880304
5/20/2016 ground squirrel 41.942901 105.77634
5/23/2016 Coyote 1 41.888334 105.864356
5/21/2016 Mountain plover 1 41.895183 105.87099
5/21/2016 Badger 1 41.894177 105.871939
5/21/2016 Coyote 1 41.893384 105.869778
5/20/2016 BAEA 1 41.887292 105.895943 outside permit area near Point 29 5/21/2016 Badger 1 41.900984 105.888458
5/21/2016 waterfowl on pond: Wilson’s 41.901881 105.88089 phalaropes, horned grebe, green-winged teal, avocet, red-winged blackbirds, widgeon 6/10/2016 Mountain plover 1 41.894791 105.866459
6/10/2016 badger 1 41.930102 105.787245
6/10/2016 FEHA 1 41.912474 105.741243
6/10/2016 GOEA 3 41.902743 105.747432
6/10/2016 BAEA 1 41.92413 105.753029
6/10/2016 ground squirrel 1 41.923037 105.785472
6/10/2016 Coyote 1 41.896952 105.847606
6/28/2016 Badger 1 41.925326 105.824889 6/28/2016 13-lined ground squirrel 1 41.941588 105.776432
6/28/2016 NOHA 1 41.927262 105.870214
6/28/2013 badger 2 41.893741 105.870339
6/28/2013 Coyote 1 41.920912 105.893443
6/29/2016 NOHA 1 41.937069 105.866262
7/13/2016 Coyote 1 41.897483 105.841064
7/13/2016 Horned toad 1 41.896303 105.84239
7/13/2016 jackrabbit 1 41.915855 105.873923
7/13/2016 Coyote 1 41.910897 105.891238
7/28/2016 Ground squirrel 1 41.928319 105.787645
7/28/2016 Badger 1 41.924501 105.805707
7/28/2016 Swift fox 4 41.898341 105.841137 Den site
7/28/2016 Coyote 1 41.903524 105.864405
8/9/2016 Badger 1 41.908469 105.888841
8/9/2016 NOHA 1 41.927262 105.870214
8/23/2016 Badger 1 41.925429 105.787554
8/23/2016 Badger 1 41.895354 105.832374
8/23/2016 Coyote 2 41.895354 105.832376
8/24/2016 Coyote 2 41.903972 105.865451
8/24/2016 Loggerhead shrike 1 41.939223 105.879822
9/7/2016 BAEA 1 41.894636 105.899429
9/7/2016 Coyote 1 41.930572 105.823536 Possible den
9/7/2016 Coyote 1 41.923641 105.828462
9/7/2016 Sage-grouse hen 1 41.932021 105.851033
9/7/2016 Badger 1 41.931718 105.852432
9/7/2016 Badger 2 41.895613 105.872302
9/7/2016 Coyote 1 41.893591 105.869696 9/20/2016 Coyote 1 41.923852 105.785092
9/20/2016 Badger 1 41.921805 105.784971
9/20/2016 Least weasel 1 41.942112 105.787809
9/20/2016 Coyote 1 41.925061 105.824715
9/20/2016 jackrabbit 1 41.903872 105.866491
10/4/2016 Coyote 2 41.930009 105. 790466
10/4/2016 Coyote 1 41.930931 105.856299
10/4/2016 Badger 1 41.895415 105.851432
10/4/2016 BAEA 1 41.883837 105.872375
10/20/2016 Coyote 1 41.942432 105.805794
10/20/2016 Coyote 2 41.890561 105.868182
11/8/2016 coyote 1 41.920101 105.815104
11/8/2016 coyote 1 41.928511 105.858183
11/25/2016 Coyote 1 41.930609 105.787386
11/25/2016 Coyote 1 41.896126 105.848464
12/4/2016 Coyote 1 41.925275 105.81848
12/9/2016 Coyote 1 41.903474 105.865902
12/8/2016 Black-footed ferret 41.908693 105.887265 Probable BFF diggings 12/23/2016 jackrabbit 1 41.911424 105.807923
12/23/2016 Coyote 1 41.90635 105.831032
12/22/2016 Coyote 1 41.921645 105.812475
1/16/2017 Coyote 1 41.909442 105.867854 Boswell Springs Incidental Observations by T. Banks Date Time Species Details 08/11/15 1453 FEHA Perched on pole south of pipeline road at turn to points 15, 16, 17. 13T 431805, 4638931 1805 GOEA On post about 900m S of point 17, flew east
08/12/15 1049 GOEA Observed within the circle of point 3 as I was leaving after having done that point, about 300m northwest of the point. Approximate coordinates 13T 4390099, 464004.
08/14/15 0850 FEHA Flushed from ground along Fetterman Road, near spring at base of hill just south of turn to point 8. Flew east, gaining elevation to about 60 m. Approximate coordinates 13T 436931, 4641827. 0852 FEHA Observed en route to point 8 about 280 m south of point, flying south at about 50m high. Approximate coordinates 13T 436181, 4641212. 1020 FEHA Flying low along Fetterman Road about .5 mile south of the turn to point 8, headed southeast slowly gaining altitude to about 75m. Approximate coordinates 13T 437337, 4641186. 1054 RTHA Directly over parking spot for walk-in access to point 1, circling and calling high overhead at about 300m. Approximate coordinates 13T 438872, 464333. 1611 FEHA On ground along Fetterman road at intersection with 2 track road which provides access to points 1,2 and 6. Flew south, staying low at about 10m. Approximate coordinates 13T 437347, 4641119.
08/28/15 1640 Swift Fox About 250m south of point 18. Possible den.
09/01/15 0855 FEHA On pole, flew south at about 10m. 13T 431805, 4638931. 1735 Prairie Rattlesnake crossing 2 track about 320m east of point 8. Photo available.
09/13/15 1724 NOHA Flying over Anabat station on west end of pond, south of Met tower. Flying west, low at about 5m. Approximate coordinates 13T 435879, 4639615. 1724 FEHA Flying over Anabat station on west end of pond south of Met tower. Flying west at about 10m. (behind the NOHA). Approximate coordinates 13T 435879, 4639590. 1724 FEHA Perched on top of Met tower. 13T 435849, 4639918.
09/14/15 1024 FEHA Flying N near corrals SW of point 18, low, 2 – 3m off ground. Approximate coordinates 13T 430374, 4638848.
09/19/15 1546 FEHA Circling above pole at intersection of pipeline road and 2- track road leading to points 15, 16,17. About 35m high, circling but generally headed south. Approximate coordinates 13T 431805, 4638931. 9/28/15 1109 AMKE Perched on fence post along route to point 1. Approximate coordinates 13T 438381, 4642254. 10/11/15 0735 FEHA Perched on Met tower on crossbar about 20m up. 13T 435849, 4639918. 0754 FEHA On ground north of 2 track leading to point 15, about 400m northwest of point 15. Approximate coordinates 13T 432410, 4636755. 1230 FEHA About 600m east of point 16, headed north at about 30m high. Approximate coordinates 13T 431789, 4636720.
10/12/15 1148 FEHA Observed from 2 track along fence en route to point 18, about 676m southwest of the point, headed south at about 50m high. Approximate coordinates 13T 430599, 4639564. 1316 FEHA Observed from pipeline road south of point 14, flying south at about 30m high. Approximate coordinates 13T 432496, 4638959. 1445 FEHA Flying north just east of fenceline as I arrived on point 6 , about 10m high. Approximate coordinates 13T 437811, 4641458.
10/24/15 1526 FEHA Perched on top of Met tower. 13T 435849, 4639918.
11/08/15 0752 FEHA Perched on fencepost just north of corrals southwest of point 18, flew west staying low at about 5 m high. Approximate coordinates 13T 430445, 4638849. 1310 RLHA Flying west, just south of pipeline road, about 30 m high. Approximate coordinates 13T 433491, 4639254. 1315 PRFA Just south of pipeline road about 1 kilometer west of met tower. Flying west, 5-10m high. 1315 RLHA Just south of pipeline road about 1 kilometer west of met tower. Flying west, 5-10 m high. Appeared to be pursuing the PRFA. Approximate coordinates 13T 434783, 4639367. 1651 BAEA (juv) North side of pipeline road just north of point 5, flying south about 30m high. Crossed over point 5. Approximate coordinates 13T 437753, 4640196.
12/4/15 1109 GOEA Perched on pole along pipeline road north of point 5. Approximate coordinates 13T 437796, 4640163.
Avian Codes: MAKE – American kestrel BAEA – Bald eagle FEHA – Ferruginous hawk GOEA – Golden eagle NOHA – Northern harrier PRFA – Prairie falcon RLHA – Rough-legged hawk RTHA – Red-tailed hawk TUVU – Turkey vulture Boswell Springs Incidental Observations 2016 Date Time Species Details 1. 4/8/16 0838 AMKE Perched on pole, approximate coordinates 13T 437795 m E, 4642339m N. 2. 4/8 1335 AMKE Perched in tree, approximate coordinates 13 T 438227 m E, 4642364 m N. 3. 4/8 1335 FEHA Perched in tree, approximate coordinates 13 T 438227 m E, 4642364 m N. 4. 4/21 1010 PRFA About 1200 m SE of point 2, flying east at about100 m up. Approximate coordinates 13T 44025 m E, 4640661 m N. 5. 4/21 1452 RTHA About 830 m NE of point 3, perched on pole. 6. 4/21 1518 RTHA About 900 m NE of point 3, approximate coordinates 13T 439877 m E, 4640610 m N. 7. 4/21 1315 FEHA (2) Circling above trees about 150 m up, approximate coordinates 13 T 438227 m E, 4642364 m N. 8. 4/21 1930 FEHA (2) Flushed from ground during approach to point 18, approximate coordinates 13T 431012 m E, 4639929 m N. 9. 5/5 0901 GOEA About 900 m E of point 4, about 75-100 m high circling N. Approximate coordinates 13T 438637m E, 4638521 m N. 10. 5/5 1210 PRFA Over fenceline west of point 18, circled and flew south at about 20 m high. Approximate coordinates 13T 430609 m E, 4639881 m N. 11. 5/5 1938 FEHA(2) Perched in tree, approximate coordinates 13 T 438227 m E, 4642364 m N. 12. 5/5 1948 SWHA Perched on top of rock formation, approximate coordinates 13T 438892 m E, 4643004 m N. 13. 5/6 0730 SWHA Perched on fence post, approximate coordinates 13T 438701 m E, 4643069 m N. 14. 5/6 0740 FEHA On nest, approximate coordinates 13 T 438227 m E, 4642364 m N. 15. 5/6 0740 AMKE Perched in tree near FEHA nest, approximate coordinates 13 T 438227 m E, 4642364 m N. 16. 5/6 0925 FEHA (2) Perched in tree, nest site. approximate coordinates 13 T 438227 m E, 4642364 m N. 17. 5/19 1139 FEHA Perched in tree. approximate coordinates 13 T 438227 m E, 4642364 m N. 18. 5/19 1312 FEHA Perched in tree. approximate coordinates 13 T 438227 m E, 4642364 m N. 19. 5/20 1301 FEHA Flying north over pipeline road, 20 to 30 m high. Approximate coordinates 13T 433151 m E, 4639251 m N. 20. 6/6 1555 SWHA Flushed from ground, flew north at about 10 m high. Approximate coordinates 13T 433115 m E, 4639208 m N. 21. 6/7 0647 FEHA Perched in tree. approximate coordinates 13 T 438227 m E, 4642364 m N. 22. 6/7 0654 FEHA Flew in and joined the above bird. 23. 6/7 0810 SWHA On a small nest, north side of bluff north of point 1, approximate coordinates 13 T 439189 m E, 4643549 m N. 24. 6/7 0910 SWHA Soaring high, 1 to 200 m up, about 2 kilometers north of point 8. Approximate coordinates 13T 436054 m E, 4643493 m N. 25. 6/7 0955 NOHA Flushed from ground, flew across Fetterman Road and flew SW at about 10 m high. Approximate coordinates 13T 437388 m E, 4641107 m N. 26. 6/29 1707 FEHA Flying low over pond south of point 9, approximate coordinates 13T 436079 m E, 4639564 m N. 27. 6/30 0705 MOPL On ground, about 100 m north of point 16. Approximate coordinates 13T 431210 m E, 4636639 m N. 28. 6/30 0830 FEHA Approximately 300 m west of point 15, flying southeast at about 20 – 30 m high. Approximate coordinates 13T 432542 m E, 4636728 m N. 29. 6/30 0840 Swift Fox About 700 m north of point 15. 30. 6/30 1005 GOEA On fence post south of pipeline road, approximate coordinates 13T 433123 M E, 4639141 m N. 31. 7/11 1850 FEHA (2) About 700 m SE of point 8. Approximate coordinates 13T 436802 m E, 4641738 m N. 32. 7/25 0916 FEHA Flying west over Fetterman road about 800 m south of pipeline road, approximate coordinates 13T 437575 m E, 4639299 m N. 33. 7/25 0917 FEHA Perched on fence post about 500 m south of pipeline road, approximate coordinates 13T 437533 m E, 4639605 m N. 34. 7/25 0922 FEHA Flying north from ridge about 700 m southeast of point 8, approximate coordinates 13T 436802 m E, 4641738 m N. 35. 7/25 0922 FEHA Flying north from ridge about 600 m south of point 8, approximate coordinates 13T 436331 m E, 4640918 m N. 36. 7/25 1044 SWHA Perched in tree. Approximate coordinates 13 T 438227 m E, 4642364 m N. 37. 7/25 1420 Swift Fox South of pipeline road north of Point 5. 38. 7/25 1754 FEHA About 650 m southeast of point 14, soaring at about 40 m high. Approximate coordinates 13T 433208 m E, 4639352 m N. 39. 7/25 1810 FEHA About 900 m north of Point 14, approximate coordinates 13 T 432624 m E, 4640811 m N. 40. 7/25 1848 FEHA Flew in and landed near the above bird. 41. 7/25 1906 GOEA Flying west, south of pipeline road, approximate coordinates 13T 431546 m E, 4638862 m N. 42. 7/25 1906 FEHA Flying west, south of pipeline road, approximate coordinates 13T 431495 m E, 4638837 m N. 43. 7/25 1910 PRFA(2) Perched on fence posts west of point 18. Approximate coordinates 13T 436662 m E, 4640028 m N. 44. 8/11 0949 FEHA(2) Flying west above fenceline south of point 17, about 50 m high. Approximate coordinates 13T 431168 Me, 4637442 m N. 45. 8/11 0952 PRFA Flying north about 100 m east of gate, about 30 m high. Approximate coordinates 13 T 432105 m E, 4637459 m N. 46. 8/11 1629 FEHA Perched on ground about 650 m SE of point 8. Approximate coordinates 13T 436791 m E, 4641560 m N. 47. 8/11 1850 FEHA On ground, aboutb1000m north of point 6, approximate coordinates 13T 437630m E, 4642460 m N. 48. 8/12 0815 PRFA Perched on fencepost at gate, flew west. Approximate coordinates 13T 437721 m E, 4641654 m N. 49. 8/25 1040 AMKE Perched on ground about 300 m Southeast of point 8. Approximate coordinates 13T 436427 m E, 4641406 m N. 50. 8/25 1112 FEHA About 1200m southwest of point 8, on ground. Approximate coordinates 13T 434998 m E, 4641045 m N. 51. 8/25 1211 SWHA Soaring about 1000 m north of point 6, about 70 m high. Approximate coordinates 13T 437668 m E, 4642459 m N. 52. 8/25 1605 FEHA Flying north over pond south of point 9, about 30 m high. Approximate coordinates 13T 435972 m E, 4639599 m N. 53. 8/25 1605 FEHA On ground about 50 m south of pond. Approximate coordinates 13T 436098 m E, 4639532 m N. 54. 8/25 1605 NOHA Flying north over pond, approximat coordinates 13T 435938 m E, 4639591 m N. 55. 8/25 1630 FEHA (2) Soaring about 600 m west of point 15, one about 50 m high, the other at about 150 m. Approximate coordinates 13T 432232 m E, 4636675 m N. 56. 8/26 0834 GOEA Perched on ridge about 1000m north of point 14, approximate coordinates 13T 432586 m E, 4640761 m N. 57. 0/7 1042 FEHA Flying south about 30 m high. Approximate coordinates 13T 431703 m E, 4638900 m N. 58. 9/7 1049 GOEA(2) Flying west about 40 m high, just west of fenceline west of point 18, approximate coordinates 13T 430668 m E, 4640090 m N. 59. 9/7 1420 GOEA Perched on post, approximate coordinates 13T 432007 m E, 4637462 m N. 60. 9/7 1709 PRFA (2) Circling over fence line about 1100 m west of point 2. Approximate coordinates 13T 438229 m E, 4641377 m N. 61. 9/8 0648 PRFA On post near gate, flew west. Approximate coordinates 13 T 437719 m E, 4641651 m N. 62. 9/8 0800 FEHA On post, west side Fetterman road, about 500 m north of Pipeline road. Approximate coordinates 13T 437392 m E, 4640596 m N. 63. 9/21 1340 PRFA Near pond northwest of point 6, flying low westbound. Approximate coordinates 13T 437469 m E, 4641818 m N. 64. 9/21 1415 FEHA Perched on met tower. 13T 435849 m E, 4639918. 65. 9/21 1455 NOHA Flying east over Spring Creek south of point 8, about 5 m high. Approximate coordinates 13T 436295 m E, 4641168 m N. 66. 9/21 1503 FEHA Flying north across pipeline road, approximate coordinates 13T 439030 m E, 4640421 m N. 67. 9/21 1540 FEHA On post, approximate coordinates 13T 439137 m E, 4640673 m N. 68. 9/21 1543 PRFA On pole, about 1000 m northeast of point 3. Approximate coordinates 13T 440029 m E, 4640619 m N. 69. 9/21 1552 FEHA On ground about1500 m west of point 3. Approximate coordinates 13T 437919 m E, 4639496 m N. 70. 9/21 1720 FEHA On ground about 1500 m west of point 5. Approximate coordinates 13T 436253 m E, 4639530 m N. 71. 9/22 0857 PRFA About 600 m southwest of point 15, flying east about 20 m high. Approximate coordinates 13T 432517 m E, 4636205 m N. 72. 10/5 1538 FEHA Perched on Met Tower. 13T 435849 m E, 4639918 m N. 73. 10/6 1122 FEHA Flushed from ground about 300 m north of point 5 during approach to point, flew south at about 30 m high. Approximate coordinates 13T 437637 m E, 4640124 m N. 74. 10/18 0829 FEHA Flying east over point 8, about 40 m high. Approximate coordinates 13T 436161 m E, 4641488 m N. 75. 10/18 1320 PRFA Flushed from ground near point 3, flew west at about 20 m high. Approximate coordinates 13T 439363 m E, 4639857 m N. 76. 10/19 1130 GOEA Soaring about 1000m south of point 17, about 150 m high. Approximate coordinates 13T 431510 m E. 4637404 m N. 1116 Albin St. (307) 742-3506 Laramie, WY 82072 Email: [email protected] www.realwestconsulting.com
DATE: August 13, 2015
PREPARED BY: Amber Travsky Real West Natural Resource Consulting 1116 Albin St. Laramie, WY 82072
PREPARED FOR: Kim Chapman and Genesis Mickel Applied Ecological Services 21938 Mushtown Road Prior Lake, MN 55372
SUBJECT: Boswell Springs Wind Farm Raptor Nest and Passerine Bird Survey Results
DISCUSSION: Passerine Bird Surveys Two passerine bird surveys were conducted with 13 sample points as shown in Figure 1. The first survey was conducted on June 29 and 30. The second survey was started on July 5 with only four sample points taken on that date. Due to extensive rain over several days, the remaining sample points were not surveyed until July 9. The field forms are scanned and will be sent via email.
Raptor Nest Surveys A brief report on the nests found during the initial ground nest survey within the permit area, conducted on June 12, 2015, has been submitted. In addition, the results of the aerial nest survey conducted on June 23 and 24 were also submitted. That listing was done quickly to provide information in a very timely manner. The revised and updated list is provided in a supplemental Excel file included as an attachment with this report.
At the request of AES and where possible, specified nests had follow-up ground checks to verify nest locations, status and condition. Some of the nests could not be ground checked due to the REAL WEST Page 2 ______lack of landowner permission. A number of nests were checked even with the lack of landowner permission but required hiking to the nests from the nearest permit area boundary. Figure 2 shows the nest identifications, for purpose of this report, of those nests where additional ground checks were requested by AES. The results of the checks are in Table 1. Photographs and other nest information are included below. Nest identifications correspond with those provided on the Excel nest list.
Table 1. Results of requested nest re-checks.
ID on map Substrate Result from Ground Check Photo No.
1 snag Good condition but too small to be GE 12
2 snag Good condition but too small to be GE 13
3 pine tree Good condition but too small to be GE 14
4 pine tree Good condition but too small to be GE 7 Could not recheck; Poor condition when 5 cottonwood viewed from the air --
6 rock outcrop Good condition but too small to be GE 15
7 rock outcrop Good condition but too small to be GE 16
8 pine tree Good condition but too small to be GE 8
9 snag Change to UNK species -- Checked the tree from the area by circling and approaching at least three 4 BAEA in times and no nest was found. This has 10 cottonwood been removed from the nest list. -- At least one young was on nest; unable 11 cottonwood to access from the ground --
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Golden Eagle 1 (Photos 1 and 2) On June 12, 2015, this nest within a pine tree, had one nearly-adult sized eaglet on the nest while one adult eagle was observed flying overhead. By July 5 the nest was empty and a second nest was noted beneath the first nest. One adult bird was roosting in the tree. Location: 13 T 426126nE; 4638079mN.
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Ferruginous Hawk Nest 1 (Photo 3) This nest is on a water tank in the extreme northwest corner of the project area and just outside the permit boundary. On June 12, 2015 the nest was active and three young were observed on the nest. The nest was empty with no birds observed on July 5, 2015. Location: 13 T 425585mE; 4644052 mN.
Ferruginous Hawk Nest 2 (Photo 4) This nest is within a cottonwood tree on the eastern third of the project area. On June 12, 2015 one young was observed on the nest; however there is the possibility that more young were present. One young was observed on July 9, 2015 with two adults exhibiting defensive behavior. Location: 13T 438257mE; 4642358mN.
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Red-tailed Hawk Nest 1 (Photos 5 and 6) This nest is located in the extreme northeast corner of the permit area. On June 12, one adult hawk was on the nest and, once it flushed, three eggs were observed in the nest. On July 9, 2015 one chick was in the nest and two adult birds were in the vicinity. Species identification as red- tail hawks is inconclusive. Location: 13T 43916mE; 4643580mN.
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Unknown Stick Nest 1 (Photo 7) This stick nest is in a pine tree just outside the permit boundary in the extreme southwest corner of the site. It is within 715 yards of the golden eagle nest 1. The nest is in good condition but is not large enough to be utilized by golden eagles. Location: 13T 425489mE; 4637959mN.
Unknown Stick Nest 3 (Photo 8) This stick nest, located in a snag, is just outside the extreme northeast corner of the permit area but is visible within the permit area. The nest was inactive but in good conditions but is not big enough to accommodate golden eagles. Location: 13 T 439581mE; 4644240mN.
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Unknown Stick Nest 4 (Photo 9) This stick nest, located in a pine tree, is approximately 55 yards south of Unknown Stick Nest 2. The nest is in good condition but too small to accommodate golden eagles. Location: 13 T 439615mE; 4644201mN.
Unknown Stick Nest 2 (Photo 10) This stick nest, located in a pine tree, is in good conditions but not big enough to accommodate golden eagles. It is just outside the southwest corner boundary. Location: 13 T 425308mE; 4638158mN.
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Swainson’s Hawk 1 (Photo 11) This nest, outside the permit area, was active on July 5, 2015 with two adults ardently protecting the nest. No young were observed, however. Location: 13 T 424655.57mE; 4638145.12mN.
Nest #5 (Photo 12) This nest is in good condition but is of insufficient size to accommodate golden eagles.
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Nest #6 (Photo 13) This nest is in good condition but is of insufficient size to accommodate golden eagles.
Nest #7 (Photo 14) This nest is in good condition but is of insufficient size to accommodate golden eagles.
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Nest #28 (Photo 15) This nest is in good condition but is of insufficient size to accommodate golden eagles.
Nest #29 (Photo 16) This nest is in good condition but is of insufficient size to accommodate golden eagles.
12 8 4 3
13 11 7
6 5 2
9 1
10
Figure 1. Passerine Bird Survey Point Numbers. 6 7 8 9
2 10 1 3 4
11
5
Figure 2. Identification of nests needing to be re-checked via ground surveys.
1116 Albin St. (307) 742-3506 Laramie, WY 82072 Email: [email protected] www.realwestconsulting.com
DATE: June 14, 2015
PREPARED BY: Amber Travsky Real West Natural Resource Consulting 1116 Albin St. Laramie, WY 82072
PREPARED FOR: Kim Chapman and Genesis Mickel Applied Ecological Services 21938 Mushtown Road Prior Lake, MN 55372
SUBJECT: Boswell Springs Wind Farm Ground Raptor Nest Survey
DISCUSSION: All previously identified raptor nests within the project site were checked on June 12, 2015. Where possible the number of young on the nest was also identified if such information could be obtained quickly to minimize disturbance.
Results Four active raptor nests were found on the permit area or along the project area boundary. The nests are shown in Figure 1. The nests include one golden eagle, two ferruginous hawk, and one red-tail hawk nest. In addition, there inactive stick nests were found; two are within the permit area and two are just outside the project area. Nests that were previously identified just north of the permit area, near the eastern half of the site, were not checked due to lack of access on the private land.
A summary and nest photos of each of the nests is provided below. REAL WEST Page 2 ______
Golden Eagle Nest This nest, within a pine tree, was not previously identified but was in an area where golden eagles were often observed. For that reason, the scattered trees in the area were thoroughly searched for any nests. The large nest is at UTM 13T 0426126mE; 4638079mN.
One nearly-adult sized eaglet was on the nest while one adult eagle was observed flying overhead.
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Ferruginous Hawk Nest 1 This previously identified nest is on a water tank in the extreme northwest corner of the project area and just outside the permit boundary. The nest was active and three young were observed on the nest.
Ferruginous Hawk Nest 2 This nest was previously identified and active. It is within a cottonwood tree on the eastern third of the project area. One young was observed on the nest, however there is the possibility that more young were present.
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Red-tailed Hawk Nest This nest was previously inactive and is located in the extreme northeast corner of the permit area. One adult hawk was on the nest and, once it flushed, three eggs were observed in the nest.
Inactive Stick Nest 1 This stick nest is in a pine tree just outside the permit boundary in the extreme southwest corner of the site. It is within 715 yards of the active golden eagle nest.
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Inactive Stick Nest 2 This stick nest, located in a snag, is just outside the extreme northeast corner of the permit area but is visible within the permit area. The nest was inactive but in good conditions.
Inactive Stick Nest 3 This stick nest, located in a pine tree, is approximately 55 yards south of Inactive Stick Nest 2. The nest is in good condition.
Figure 1. Aerial photograph of the raptor nest locations.
Boswell Springs Wind Farm
June 2015 AES Raptor Nest Surveys *# *# .! *# Site Boundary *# *# *# 10 mile Buffer *# *# NESTS Species, Status .! .! *#*# BE, Occupied .!*# *# .! .! FH, Occupied *# FH, Unoccupied .! )".! .! GE, Occupied
Fetterman Rd. *# GE, Unoccupied .! RT, Occupied *#*# *# .! UNK, Occupied *# UNK, Unoccupied *# *#*# .!*#.! *# Eagle congregation areas )" 12+ GE and BE .! .! .! )" 4 BE ! . .! *#.! *# *#
.! .! .!
*# .! *# .!
*# )" .! Data Sources: .! ESRI Street Map *# 2009 NAIP Aerial .! Applied Ecological Services, Inc. 21938 Mushtown Road Prior Lake, MN 55372 .! 952-447-1919 www.appliedeco.com 0 1.5 3 6 Miles ±
1116 Albin St. (307) 742-3506 Laramie, WY 82072 Email: [email protected] www.realwestconsulting.com
DATE: May 7, 2015
PREPARED BY: Amber Travsky Real West Natural Resource Consulting 1116 Albin St. Laramie, WY 82072
PREPARED FOR: Kim Chapman and Genesis Mickel Applied Ecological Services 21938 Mushtown Road Prior Lake, MN 55372
SUBJECT: Boswell Springs Wind Farm Sage-grouse Lek Surveys
DISCUSSION: Surveys were conducted for the Boswell Springs Wind Farm project. The methodology and the results are presented below.
Methods Amber Travsky, a wildlife biologist with Real West Natural Resource Consulting, conducted surveys on the proposed Boswell Spring Wind Farm. The purpose of the surveys was to search for previously documented sage-grouse leks and search the project area and a 2-mile buffer area for previously undocumented leks.
The surveys were conducted on April 22 and 29 and May 6, 2015. The sage-grouse surveys followed Wyoming Game and Fish Department (WGFD) protocol with the surveys a minimum of 7 days apart and each being conducted from first light to an hour after sunrise.
Surveys were conducted by driving roads within the survey area, particularly the southern and eastern boundaries where previously reported sage-grouse leks are located and in suitable habitat within a 2-mile buffer. The site’s northwest corner was closely inspected due to the higher REAL WEST Page 2 ______density of sagebrush and prevalence of suitable habitat for sage-grouse. Stops were made approximately every half-mile in sagebrush habitat to listen for sounds of grouse. Known historical lek sites on or within two miles of the site were specifically checked (Table 1). The 2014 lek status, as reported by the Wyoming Game and Fish Department is also listed in Table 1.
Results During all three survey sessions the ground was clear of snow. The temperature during the dawn surveys ranged from 30 to 38 degrees to start the survey and rising approximately 10 degrees in the course of the survey. Winds varied only slightly, from calm to less than 5 mph out of the northwest. Cloud cover varied from 0 to 100 percent. Conditions in general were cool and calm and well within the parameters required in the protocol for sage-grouse surveys.
During the three surveys, no sage-grouse were seen or heard. While suitable habitat is present, particularly in the northwest corner of the site, no sage-grouse were observed on the site or within 2-miles.
Results of a search of the Wyoming Interagency Spatial Database and Online Management (WISDOM) System on March 24, 2015 indicated the project area remains outside any sage-grouse core area and there are no occupied leks within two miles of the site.
Table 1. Historical sage-grouse leks located on or near the Boswell Springs Wind Farm.
Distance from 2014 WGFD Lek Name Zone & Easting Northing Site Status Fetterman 21 13T 439100mE 4636200mN 0.78 mi southeast Unoccupied
Fetterman 22 13T 437101mE 4639491mN On site Unoccupied
Cordingly 13T 426000mE 4641800mN On site Not listed
Rock Creek 13T 426700mE 4632000mN 3.5 mi south Unoccupied Bend
Memorandum
To: Mr. Paul Martin, Intermountain Wind
From: Kim Chapman, Genesis Mickel, Patrick Daniels
Re: Preliminary Boswell Bat acoustic monitoring report (AES #15-0285) DRAFT
Date: January 8, 2015
Applied Ecological Services, Inc. (AES) was retained to assess the potential impacts on bats and bat activity in a 22,000 acre wind farm in Albany and Carbon Counties, Wyoming. Boswell Springs is located 23 miles east of Medicine Bow. Current wind farm plans call for 150 2.3MW turbines with 80m hub height and 107m rotor diameter. Thus the top of the rotor swept area will be 133.5m (438.0ft).
Data collected in 2015 will be used to assist in turbine layout and in the regulatory review process. The data will be compared to data collected in 2009-2011 in order to evaluate whether ecological and biological conditions have not changed since that time. If no change is observed, it may not be necessary to repeat these surveys in 2016 because the 2009-2011 and 2015 data would provide a two-year data set for use in turbine siting and regulatory review.
For this study, AES followed U.S. Fish and Wildlife Service (USFWS) land-based wind energy guidelines, Tier 3 (USFWS 2012). In August 2015, four AnaBat SD2 Bat Detector recording units (detectors) were deployed across the Boswell Springs site to document site-specific bat activity. Monitoring locations are shown in Map Exhibit 1 and correspond to 2009-2011 monitoring locations. All 2015 monitoring locations used a 4.5 m tower to place the microphone above ground noise. Sites 1, 2 and 4 represent wetland and water feature areas. These detectors were recording until October 23, 2015. Sites 3, 5, 6, and 7 represented upland grasslands. Previous acoustic monitoring efforts showed little bat activity in upland areas, so only one detector was used to monitor all of these sites at two week intervals, starting with site 6 from Aug 28-Sept 13, then site 3 from Sept 13-Sept 25, then site 5 from Sept 25-Oct 8, and finally site 7 from Oct 8-Oct 21. Despite anchoring, unit #4 was tipped over for two weeks, but nevertheless recorded bat call data. At the download session on October 11, the unit was raised again to the full 4.5 meter height. Detectors were deployed across the site in a typical configure, as shown for detector site 1, below.
Figure 1. Bat detector set-up at site 1
Call files were identified automatically using the Kaleidoscope and BCID programs, both of which are USFWS-approved software packages. Call data were summarized to illustrate the bat activity pattern at the Boswell site. BCID was primarily used for automatic identification of eastern bat species, and as such is reliable only for classifying the frequency range of the calls at the site into high, mid-range, and low frequency. Kaleidoscope was used as the primary identification software because it uses a call library of all western species of bats. Table 1. Site deployment dates and total detector nights
Type of Site Number Start Date End Date Detector Nights deployment Primary Habitat
1 8/28/2015 10/23/2015 57 Fixed Wetlands/Water
2 8/28/2015 10/23/2015 57 Fixed Wetlands/Water
3 9/13/2015 9/24/2015 12 Rotational Grasslands
4 8/28/2015 10/22/2015 55 Fixed Wetlands/Water
5 9/25/2015 10/8/2015 14 Rotational Grasslands
6 8/28/2015 9/12/2015 16 Rotational Grasslands
7 10/10/2015 10/21/2015 12 Rotational Grasslands
Kaleidoscope analysis identified ten bat species at the site. These were Big brown bat (Eptesicus fuscus), Western red bat (Lasiurus blossevilli), Hoary bat (Lasiurus cinereus), Silver-haired bat (Lasionycteris noctivagans), California myotis (Myotis californicus), Western small-footed myotis (Myotis ciliolabrum), Little brown myotis (Myotis lucifugus), Fringed myotis (Myotis thysanodes), Long-eared myotis (Myotis evotis), and Long-legged myotis (Myotis volans).
2
Table 2. Site 1 bat activity by species
Total Calls Per Species Calls Detector-Night % All Calls
Big brown (EPFU) 3 0.1 0.9
Western red (LABL) 6 0.1 1.8
Hoary (LACI) 33 0.6 10.2
Silver-haired (LANO) 127 2.2 39.1
California myotis (MYCA) 6 0.1 1.8
Western small-footed (MYCI) 11 0.2 3.4
Long-eared myotis (MYEV) 1 0.0 0.3
Little brown (MYLU) 102 1.8 31.4
Fringed myotis (MYTH) 2 0.0 0.6
Long-legged myotis (MYVO) 22 0.4 6.8
Unknown 12 0.2 3.7
Total Calls 325 5.7 100.0
Figure 2. Site 1 bat activity by date
Total Bat Calls Mean Temperature °F 180 70
160 F)
60 ° 140
50 120
100 40
80 30 Number of Calls 60
20 Daily Mean Temperature ( 40 10 20
0 0
Date
3
Table 3. Site 2 bat activity by species
Total Calls Per Species Calls Detector-Night % All Calls
Big brown (EPFU) 56 1.0 5.9
Western red (LABL) 9 0.2 1.0
Hoary (LACI) 262 4.6 27.7
Silver-haired (LANO) 413 7.2 43.7
California myotis (MYCA) 4 0.1 0.4
Western small-footed (MYCI) 22 0.4 2.3
Long-eared myotis (MYEV) 1 0.0 0.1
Little brown (MYLU) 96 1.7 10.1
Long-legged myotis (MYVO) 37 0.6 3.9
Unknown 46 0.8 4.9
Total Calls 946 16.6 100.0
Figure 3. Site 2 bat activity by date
Total Bat Calls Mean Temperature °F 180 70
160 F)
60 ° 140
50 120
100 40
80 30 Number of Calls 60
20 Daily Mean Temperature ( 40 10 20
0 0
Date
4
Table 4. Site 3 bat activity by species
Total Calls Per Species Calls Detector-Night % All Calls
Hoary (LACI) 1 0.1 25.0
Silver-haired (LANO) 2 0.2 50.0
Little brown (MYLU) 1 0.1 25.0
Total Calls 4 0.3 100.0
Figure 4. Site 3 bat activity by date
Total Bat Calls Mean Temperature °F 180 70
160 F)
60 ° 140
50 120
100 40
80 30 Number of Calls 60
20 Daily Mean Temperature ( 40 10 20
0 0
Date
5
Table 5. Site 4 bat activity by species
Total Calls Per Species Calls Detector-Night % All Calls
Big brown (EPFU) 3 0.1 1.0
Western red (LABL) 6 0.1 2.1
Hoary (LACI) 33 0.6 11.4
Silver-haired (LANO) 127 2.3 43.9
California myotis (MYCA) 6 0.1 2.1
Western small-footed (MYCI) 11 0.2 3.8
Long-eared myotis (MYEV) 1 0.0 0.3
Little brown (MYLU) 102 1.9 35.3
Fringed myotis (MYTH) 2 0.0 0.7
Long-legged myotis (MYVO) 22 0.4 7.6
Unknown 12 0.2 4.2
Total Calls 289 5.3 100.0
Figure 5. Site 4 bat activity by date
Total Bat Calls Mean Temperature °F 180 70
160 F)
60 ° 140
50 120
100 40
80 30 Number of Calls 60
20 Daily Mean Temperature ( 40 10 20
0 0
Date
6
Table 6. Site 5 bat activity by species
Total Calls Per Species Calls Detector-Night % All Calls
Hoary (LACI) 3 0.2 7.1
Silver-haired (LANO) 6 0.4 14.3
Unknown 33 2.4 78.6
Total Calls 42 3.0 100.0
Figure 6. Site 5 bat activity by date
Total Bat Calls Mean Temperature °F 180 70
160 F)
60 ° 140
50 120
100 40
80 30 Number of Calls 60
20 Daily Mean Temperature ( 40 10 20
0 0
Date
7
Table 7. Site 6 bat activity by species
Total Calls Per Species Calls Detector-Night % All Calls
Big brown (EPFU) 3 0.2 2.2
Western red (LABL) 6 0.4 4.3
Hoary (LACI) 17 1.1 12.3
Silver-haired (LANO) 86 5.4 62.3
California myotis (MYCA) 6 0.4 4.3
Western small-footed (MYCI) 11 0.7 8.0
Long-eared myotis (MYEV) 1 0.1 0.7
Unknown 8 0.5 5.8
Total Calls 138 8.6 100.0
Figure 7. Site 6 bat activity by date
Total Bat Calls Mean Temperature °F 180 70
160 F)
60 ° 140
50 120
100 40
80 30 Number of Calls 60
20 Daily Mean Temperature ( 40 10 20
0 0
Date
8
Table 8. Site 7 bat activity by species
Total Calls Per Species Calls Detector-Night % All Calls
Silver-haired (LANO) 3 0.3 33.3
Unknown 6 0.5 66.7
Total Calls 9 0.8 100.0
Figure 8. Site 7 bat activity by date
Total Bat Calls Mean Temperature °F 2.5 70
F)
60 ° 2
50
1.5 40
30
Number of Calls 1
20 Daily Mean Temperature ( 0.5 10
0 0
Date Ten species of bats were encountered during two months of acoustic monitoring during the fall migration period. No state or federally-threatened or endangered species of bats were detected. Most of the bats detected are considered Species of Special Concern and all are protected from take (harm, harass, kill) under Section 11, Chapter 52 of the Wyoming Game and Fish Regulations. The three fixed detectors located along wetlands and waterways were deployed for 56 days each on average. The number of bat calls ranged from 5.3 to 16.6 calls per detector night. The migratory tree bats, Hoary bat and Silver-haired bat, together with Little brown myotis consistently accounted for 70-80% of all calls at these locations. In 2010 similar activity levels were recorded at these same three locations, 1.0 to 10.4 calls per detector night. The greatest bat activity occurred at a reservoir along the main stem of a creek in the eastern part of the site. The detector that was rotated through grasslands at two-week intervals recorded 0.3 to 8.6 calls per detector night. At three of the four detectors, activity was 0.3-3.0 calls per detector night, consistent with the low activity level of 0.0 to 0.4 calls per detector night recorded in 2010. At the fourth location, Site 6, located just west of Fetterman Road, the detector recorded a higher than expected number of calls for grassland habitat.
9
This detector was deployed early in the migration period when large numbers of Hoary and Silver-haired bats were passing through the site. These migratory tree bats likely originate much farther north of the site and are flying south to more densely forested landscapes south of the site.
10
MAP EXHIBIT 1.
January 4, 2012
Mr. Paul Martin Intermountain Wind P.O. Box 353 Boulder, CO 80306
Subject: Observations of Golden Eagle and Ferruginous Hawk at the Boswell Springs Wind Farm (AES 08-0853) during 2011
Dear Paul Martin, During the 2010 raptor search of the Boswell Springs site one Ferruginous Hawk nest was discovered on site, and two Golden Eagle nests (one occupied and one unoccupied) were discovered off site (Map Exhibit 1). The Ferruginous Hawk nest was located in the northeastern portion of the site. The occupied Golden Eagle nest was located just over one mile southwest of the site. The unoccupied Golden Eagle nest was located just northwest of the site. These nest locations and possible impacts from wind development at the site to Golden Eagles and Ferruginous Hawks were discussed in a meeting with U.S. Fish and Wildlife Service (USFWS) on March 18, 2011. The USFWS requested additional observations of Golden Eagle and Ferruginous Hawk flight behavior at the site. A survey method was also recommended and discussed in the context of obtaining information that could be used in a model of wind project impacts to eagles being developed by the USFWS. This memo describes these surveys, the results of these surveys and discusses implications of these surveys for wind development at the site.
Regulations and Guidance
Bald Eagle and Golden Eagle Protection Act The Bald and Golden Eagle Protection Act (BGEPA) assigns legal authority to the USFWS to protect Bald and Golden Eagles from takings and disturbance. Rules for the issuance of permits under the BGEPA were finalized on September 11, 2009 (USFWS 2009). Permitted activities do not distinguish between lethal and non-lethal take, such as nest disturbance. Activities that affect either individual eagles or important eagle use areas are regulated. Important eagle use areas include nests, foraging areas, communal roost sites and the landscape features surrounding such sites that are essential for the continued viability of the site. Draft guidance for developing wind energy projects related to eagles was recently published by the USFWS (2011b). They were open for public comment until May 19, 2011, and finalized guidance are expected later in 2011 or early 2012. Although draft, this guidance is being actively used by the USFWS. The guidance recommends the development of an Eagle Conservation Plan if known important eagle use areas occur within 10 miles of a project footprint. If the Eagle Conservation Plan can demonstrate that all “incidental take” is avoided, minimized or mitigated through Advanced Conservation Practices, Avian Protection Plans or Wildlife Hazard Management Plans then a programmatic take permit may not be necessary.
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Programmatic take permits are issued for projects that undertake activities that may disturb or otherwise take eagles on an on-going basis and generally incorporate the implementation of Advanced Conservation Practices, the development of Avian Protection Plans or Wildlife Hazard Management Plans as a condition of the permit. Individual or “one-time” take permits are issued for the removal of eagle nests, direct take of individual eagles, and grandfathered incidental take permits issued under Section 7 of the Endangered Species Act (ESA). The BGEPA permitting process limits the number of permits issued for Golden Eagle under the BGEPA to no net loss of population for the regional population, and provides separate provisions for a programmatic take permit versus individual instances of a take. Golden Eagle populations are believed to be declining, and all incidental take of Golden Eagles is likely to require mitigation. In addition, this permit type also requires basic post-construction monitoring. The draft guidance suggests that Federal permitting for continuous but low-level takings, such as at a wind energy project, will trigger a review under the National Environmental Policy Act (NEPA 1969). Discussion and research in collaboration with the USFWS on a project by project basis is necessary to determine level of take and the possible need for a programmatic take permit.
Migratory Bird Treaty Act The Migratory Bird Treaty Act of 1918 (MBTA) assigns legal authority to the USFWS to protect migratory birds from takings. These include over 800 species of raptor, diurnal migrant and passerine migrant birds. Like the BGEPA, the MBTA only regulates direct takings, and not habitat modifications. The level of direct taking by a wind energy facility which would invoke prosecution under the MBTA has not been established. There is currently no mechanism to grant permission for incidental takings under the MBTA. The USFWS believes that it has the authority to create a process similar to that developed for the BGEPA under the MBTA, but has not begun to develop the necessary regulations (USFWS 2008).
Wind Development Guidance Guidance, recommendations and regulations regarding wind project development and wildlife impacts are still being developed and are constantly changing. On February 8, 2011 the USFWS released draft land-based wind energy guidelines to mitigate impacts to wildlife and their habitats related to land-based wind energy facilities (USFWS 2011a). These guidelines were open for public comment until May 19, 2011. A revised draft was published September 13, 2011, and was open for public comment until September 23, 2011 (USFWS 2011c). The draft guidelines outline a tiered research approach that includes searches of existing literature and data to identify potential issues of concern, field studies to provide additional data where necessary, and post-construction mortality studies to identify and quantify impacts. This guidance document recommends that wind developers voluntarily adhere to these guidelines and communicate with the USFWS as part of their due diligence process in order to avoid, minimize and mitigate impacts to species protected under the BGEPA and MBTA. Adherence to the guidelines is required for projects on federal lands. In turn the USFWS will consider adherence to the guidelines as evidence of due care, and “will take such adherence and communication fully into account when exercising its discretion with respect to any potential referral for prosecution” (USFWS 2011a). Previously, the USFWS had published Interim Voluntary Guidelines (USFWS 2003) which outlined recommendations for site and turbine design and operations and presented a quantitative method for initial site evaluation. The 2003 guidelines were not widely used and the 2011 guidelines will replace them.
Methods Surveys for Golden Eagle and Ferruginous Hawk activity were conducted at the Boswell Springs site from late April through August 2011 (Table 1), coinciding with the expected breeding and fledging periods for these species. Observations were conducted once in April, and twice during each subsequent month through August (Table 2). Observations consisted of three 2-hour survey periods at each point on each visit. Surveys were conducted at three points (Map Exhibit 1 & 2) located to provide clear and distant views of the site near known nests of Ferruginous Hawk and Golden Eagle, and to view as much of the site as possible. One point was located in the northeastern portion of the site approximately one mile northeast of an active
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Ferruginous Hawk nest. Two locations were in the western portion of the site. The southwestern point was located near a Golden Eagle nest known to be active in 2010, and presumed to be active in 2011. The northwestern point was located near a nest identified as unoccupied in 2010 and presumed to be an unoccupied eagle nest. In 2011 this nest was actively used by a pair of Ferruginous Hawks. Viewsheds from each point (Table 1) are shown on Map Exhibits 1 & 2. The three viewsheds combined represented 67% of the total site area. Views from the southwestern point were partially blocked by the elevation changes. Activity within the drainage itself could not be observed to the northeast; however the sky above this area was clearly visible.
Table 1. Hours of observation and viewshed areas at the Boswell Springs site Location Total Hours of Viewshed (km2) Viewshed within Project Observation Footprint (km2) Northeast 53.8 84 24 Northwest 54.0 25 11 Southwest 54.0 45 25
Table 2. Survey dates and weather conditions at the Boswell Springs site Month Dates General Conditions Chilly and windy. Temps ranged from 35 to 45 degrees with April 28 and 29 winds 10 to 20 mph. Snowfall by end of survey, limiting visibility. Mild and windy. Temps ranged from 40 to 70 degrees. Calm May 7 and 8 in early a.m. and then windy. Cool, variable winds. Temps ranged from 35 to 55 and winds 24 and 25 from calm in the morning to 20 mph. Some light rain during the survey. Mild temperatures from 40 to 70 degrees but very breezy June 7 and 8 except in the early morning. Calm in the morning but winds up to 30 mph in the afternoon. Mild temperatures with low of 39 early in the a.m. and then 21 and 22 up to 70 during day. Breezy with winds up to 20 mph. Pleasant temperatures from 55 to 75 degrees with breeze up July 8 and 9 to 15 mph. Mosquitoes plentiful. Mild temperatures from 55 to 75 degrees. Winds calm early 26 and 27 and late but up to 20 mph in middle of the day. Some light rain. Mild to hot with temperatures from 55 to 85 degrees. Winds August 4 and 5 mild, up to 10 mph in middle of the day. Mild in the morning at 50 degrees to a warm 80 degrees in 16 and 17 the middle of the day. Calm in morning with breeze at 15 mph in the middle of the day.
The viewshed at each point was divided into a grid of ½ by ½ mile cells to facilitate the mapping of flight paths. For each observation data recorded were: all eagles or Ferruginous Hawks observed, grid cell, flight behavior, distance and direction from the observer, and weather conditions. The flight origin direction and flight direction from the survey point, the flight height and time of observation were recorded. Estimates of flight heights were based on comparison with known heights of existing objects. Survey data were entered into an Access database for storage and analysis.
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Survey time of day varied at each point between dawn and dusk. Surveys were not performed in steady rain, fog, or steady winds over 25mph. Observations were made from within a parked vehicle in order to minimize disturbance due to presence at the site. Minutes of observed flight time were assigned to each individual gird cell observation. A perched bird not observed to leave its perch was assigned 1 minute of flight time within the grid cell. Minutes of flight time were totaled by grid cell separately for Golden Eagle and Ferruginous Hawk. Minutes of flight time were totaled for each viewshed and the minutes of flight time per minutes of observation at the point per unit area was calculated.
Results & Discussion
Golden Eagle Golden Eagles were observed from all three observation points (Table 3, Map Exhibit 1). From the northeast point Golden Eagle observations were rare. Most observations occurred off-site near the Wheatland Reservoir. Eagles flying near the reservoir were observed flying over the southern portion of the site on two occasions. One of these observations consisted of a single eagle, and the second of two eagles. An eagle was also observed flying off-site to the north of the site. At the northwest point observations also were rare. Eagle activity was slightly more frequent off-site to the north of the site, but even at that location few observations of eagles were made. The greatest Golden Eagle activity occurred at the southwest point, as expected due to the proximity of an active nest southwest of the site. The nest was known to be active in 2010. Nesting status in 2011 was not determined. The greatest activity from this presumed nest occurred northeast of the observation point along the escarpment paralleling Seven Mile Creek. About three-quarters of all observations occurred in an east- west corridor more or less parallel to Seven Mile Creek. The corridor was about a mile wide and extended eastward into the site for about 2.5 miles. There were few observations along the south edge of the project despite the fact that this area lies between Seven Mile Creek and active nest. This pattern of activity suggests that this eagle pair has a strong orientation to Seven Mile Creek and the adjacent area, perhaps using it as a travel corridor which connects to the Rock River where the nest is. The greater presence of eagles along the escarpment in the vicinity of Seven Mile Creek may be associated with favorable wind patterns at that location (west to south slopes with updrafts), or favorable foraging grounds in that vicinity, or a flight path to and from foraging grounds, or a combination of these factors. There is some correlation between activity and prairie dog density (Map Exhibit 2), suggesting that the eagles spend more time foraging in areas near the nest with higher prairie dog density. Eagles spent limited time in low prairie dog density areas closer to the nest site. This correlation is complicated by factors such as foraging range, and typical flight paths between foraging areas and the nest. Whatever the case, this location appears to comprise a use area for the pair of eagles nesting to the southwest. Other locations in the project boundary are not regularly used, although occasionally eagles pass through those areas.
Table 3. Flight observations at the Boswell Springs Site Location Golden Eagle Ferruginous Hawk Flight Minutes Flight Minutes/Minutes Flight Minutes Flight Minutes/Minutes of Observed on Site of Observation/km2 Observed on Site Observation/km2 Northeast 8 0.0001 579 0.007 Northwest 4 0.0001 4 0.0001 Southwest 211 0.004 1 0.00001
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Ferruginous Hawk Ferruginous Hawks were also observed from all observation points (Table 3, Map Exhibit 2), although only one flight was observed from the southwest point. This flight occurred just north of the observation point. The northwest point also had a low level of Ferruginous Hawk activity. The greatest activity was observed off-site near the active nest and to the north of the observation point, north and east of the nest. As mentioned, this nest was identified in 2010 as a possible unoccupied Golden Eagle nest. In 2011 it was occupied by a pair of Ferruginous Hawks. The greatest Ferruginous Hawk activity was recorded from the northeastern observation point. An active Ferruginous Hawk nest was located southwest of the point. About three-quarters of all observations occurred within 0.5 mile of the nest. Nearly all observations were within 1 mile of the nest. Most of the observed activity was from the nesting pair associated with this nest. Occasionally three Ferruginous Hawks were observed flying together. It is likely that there is another nest north of the site, and individuals may have been involved in territorial defense. Ferruginous Hawk activity was not correlated with prairie dog density (Map Exhibit 2), which suggests that prairie dog may not be the primary prey at this site.
Additional Observations Two additional unoccupied nest sites were identified in 2011 within the project site. One nest site just east of the southwestern observation point has a large stick nest in a tree with a second nest below. These nests are likely to be unoccupied Golden Eagle nests. The second nest site is located on a windmill just west of the northwestern observation point. This nest is in poor condition. Researchers not associated with the project were spot-lighting for Black-footed Ferret (Mustela nigripes) south of the site when AES was conducting the eagle surveys. A. Travsky (personal communication) observed the spot-lighting and has learned through her relationships with wildlife researchers that the ferret has been found near Wheatland Reservoir No. 3. Black-footed Ferret were introduced into the Shirley Basin and surrounding area, and this population is a nonessential experimental population (NEP) under section 10(j) of the ESA, as amended (USFWS 1991). As a NEP, the Black-footed Ferret is regulated as a Threatened, not Endangered Species. In addition, normal rules pertaining to Federal Threatened species may be modified by the USFWS. In the case of this NEP, individuals and corporations will be exempt from prosecution for accidental or incidental takings during the course of otherwise lawful activities. Two Mountain Plovers were observed on April 29th in the southwestern portion of the site near the southwestern observation point. This was during the spring migration. They were not observed again on the site. Mountain Plover is currently a candidate for listing under the ESA. Mountain Plover have been sought but not observed in previous surveys. Two bull Elk were observed near the center of the site on June 7th.
Applications and Next Steps The observation data on Bald Eagle and Ferruginous Hawk at the Boswell Springs wind project can be interpreted as follows. Eagle activity was greatest in the vicinity of an active eagle nest off-site to the southwest and Ferruginous Hawk activity was greatest around an active nest in the northeast portion of the site. Eagle and hawk activity was rare to non-existent over the remainder of the site. In addition, eagle and hawk activity exhibited an inverse relationship—where eagle activity was high, hawk activity was very low, and where hawk activity was high, eagle activity was very low. Nearly three-quarters of Ferruginous Hawk activity in the northeast part of the site occurred within 0.5 miles of the nest, and nearly all activity occurred within 1 mile of that nest. Three-quarters of the Bald Eagle activity occurred within 1 mile of Seven Mile Creek. These two locations appear to pose a significantly higher risk to eagles and Ferruginous Hawks than the remainder of the site. Future activity related to eagles and hawks at Boswell Springs could consist of the following: 1. Discuss the findings of this study with USFWS and Wyoming Game and Fish (WYG&F).
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2. Use the data on eagle use of the site in the USFWS eagle mortality model and predict expected mortality at the site. Use this outcome to decide on future steps, including implementation of advanced conservation practices (ACPs) as described in the eagle conservation planning guidance. 3. Decide on a process of engaging with USFWS and WYG&F in order to determine whether an eagle programmatic take permit is likely to be required for the site. Also discuss implications of Ferruginous Hawk use of the site. Because the species is not threatened or endangered, it is not covered by the federal or state endangered species laws; this is likely to consist of a set-back requirement. 4. If warranted, in the two years prior to construction, complete a second season of surveys for Golden Eagle and Ferruginous Hawk. 5. If warranted, combine the two years of survey data and re-run the eagle mortality model. Decide on ACPs to reduce or eliminate eagle mortality. Decide on how to approach the USFWS and WYG&F regarding likelihood of requiring a programmatic take permit for eagles. 6. Lay out a plan and budget for obtaining a programmatic take permit for Golden Eagle, if required.
Literature Cited USFWS (US Fish and Wildlife Service). 1991. Endangered and threatened wildlife and plants: establishment of a nonessential experimental population of Black-footed Ferrets in southeastern Wyoming. Federal Register 56(162):41473-41489. USFWS – Wind Turbine Guidelines Advisory Committee. 2003. Interim guidelines to avoid and minimize wildlife impacts from wind turbines. Washington, DC. USFWS Wind Turbine Guidelines Advisory Committee – Legal Subcommittee. 2008. Legal White Paper. http://www.fws.gov/habitatconservation/windpower/Subcommittee/Legal/Reports/Wind_Turbin e_Advisory_Committee_Legal_Subcommittee_White_Paper_(Final_As_Posted).pdf (Accessed 2008). USFWS. 2009. Eagle permits; take necessary to protect interests in particular localities; final rules. Federal Register. 50CRF Parts 13 and 22. USFWS. 2011a. U.S. Fish and Wildlife Service Draft Land-based wind energy guidelines. http://www.fws.gov/windenergy/docs/Wind_Energy_Guidelines_2_15_2011FINAL.pdf (Accessed 2011). USFWS. 2011b. Draft eagle conservation plan guidance. Washington, DC. http://www.fws.gov/windenergy/docs/ECP_draft_guidance_2_10_final_clean_omb.pdf (Accessed 2011). USFWS. 2011c. U.S. Fish and Wildlife Service Draft Land-based wind energy guidelines. http://www.fws.gov/windenergy/docs/WEG_September_13_2011.pdf (Accessed 2011).
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Map Exhibit 1. Golden Eagle Monitoring Locations and Minutes Observed
Map Exhibit 2. Ferruginous Hawk Monitoring Locations and Minutes Observed
November 3, 2011
Mr. Paul Martin Intermountain Wind P.O. Box 353 Boulder, CO 80306
Subject: Observations of Golden Eagle and Ferruginous Hawk at the Boswell Springs Wind Farm (AES 08-0853) during 2011
Dear Paul Martin, During the 2010 raptor search of the Boswell Springs site one Ferruginous Hawk nest was discovered on site, and two Golden Eagle nests (one occupied and one unoccupied) were discovered off site (Map Exhibit 1). The Ferruginous Hawk nest was located in the northeastern portion of the site. The occupied Golden Eagle nest was located just over one mile southwest of the site. The unoccupied Golden Eagle nest was located just northwest of the site. These nest locations and possible impacts from wind development at the site to Golden Eagles and Ferruginous Hawks were discussed in a meeting with U.S. Fish and Wildlife Service (USFWS) on March 18, 2011. The USFWS requested additional observations of Golden Eagle and Ferruginous Hawk flight behavior at the site. A survey method was also recommended and discussed in the context of obtaining information that could be used in a model of wind project impacts to eagles being developed by the USFWS. This memo describes these surveys, the results of these surveys and discusses implications of these surveys for wind development at the site.
Regulations and Guidance
Bald Eagle and Golden Eagle Protection Act The Bald and Golden Eagle Protection Act (BGEPA) assigns legal authority to the USFWS to protect Bald and Golden Eagles from takings and disturbance. Rules for the issuance of permits under the BGEPA were finalized on September 11, 2009 (USFWS 2009). Permitted activities do not distinguish between lethal and non-lethal take, such as nest disturbance. Activities that affect either individual eagles or important eagle use areas are regulated. Important eagle use areas include nests, foraging areas, communal roost sites and the landscape features surrounding such sites that are essential for the continued viability of the site. Draft guidance for developing wind energy projects related to eagles was recently published by the USFWS (2011b). They were open for public comment until May 19, 2011, and finalized guidance are expected later in 2011 or early 2012. Although draft, this guidance is being actively used by the USFWS. The guidance recommends the development of an Eagle Conservation Plan if known important eagle use areas occur within 10 miles of a project footprint. If the Eagle Conservation Plan can demonstrate that all “incidental take” is avoided, minimized or mitigated through Advanced Conservation Practices, Avian Protection Plans or Wildlife Hazard Management Plans then a programmatic take permit may not be necessary.
Programmatic take permits are issued for projects that undertake activities that may disturb or otherwise take eagles on an on-going basis and generally incorporate the implementation of Advanced Conservation Practices, the development of Avian Protection Plans or Wildlife Hazard Management Plans as a condition of the permit. Individual or “one-time” take permits are issued for the removal of eagle nests, direct take of individual eagles, and grandfathered incidental take permits issued under Section 7 of the Endangered Species Act (ESA). The BGEPA permitting process limits the number of permits issued for Golden Eagle under the BGEPA to no net loss of population for the regional population, and provides separate provisions for a programmatic take permit versus individual instances of a take. Golden Eagle populations are believed to be declining, and all incidental take of Golden Eagles is likely to require mitigation. In addition, this permit type also requires basic post-construction monitoring. The draft guidance suggests that Federal permitting for continuous but low-level takings, such as at a wind energy project, will trigger a review under the National Environmental Policy Act (NEPA 1969). Discussion and research in collaboration with the USFWS on a project by project basis is necessary to determine level of take and the possible need for a programmatic take permit.
Migratory Bird Treaty Act The Migratory Bird Treaty Act of 1918 (MBTA) assigns legal authority to the USFWS to protect migratory birds from takings. These include over 800 species of raptor, diurnal migrant and passerine migrant birds. Like the BGEPA, the MBTA only regulates direct takings, and not habitat modifications. The level of direct taking by a wind energy facility which would invoke prosecution under the MBTA has not been established. There is currently no mechanism to grant permission for incidental takings under the MBTA. The USFWS believes that it has the authority to create a process similar to that developed for the BGEPA under the MBTA, but has not begun to develop the necessary regulations (USFWS 2008).
Wind Development Guidance Guidance, recommendations and regulations regarding wind project development and wildlife impacts are still being developed and are constantly changing. On February 8, 2011 the USFWS released draft land-based wind energy guidelines to mitigate impacts to wildlife and their habitats related to land-based wind energy facilities (USFWS 2011a). These guidelines were open for public comment until May 19, 2011. A revised draft was published September 13, 2011, and was open for public comment until September 23, 2011 (USFWS 2011c). The draft guidelines outline a tiered research approach that includes searches of existing literature and data to identify potential issues of concern, field studies to provide additional data where necessary, and post-construction mortality studies to identify and quantify impacts. This guidance document recommends that wind developers voluntarily adhere to these guidelines and communicate with the USFWS as part of their due diligence process in order to avoid, minimize and mitigate impacts to species protected under the BGEPA and MBTA. In turn the USFWS will consider adherence to the guidelines as evidence of due care, and “will take such adherence and communication fully into account when exercising its discretion with respect to any potential referral for prosecution” (USFWS 2011a). Previously, the USFWS had published Interim Voluntary Guidelines (USFWS 2003) which outlined recommendations for site and turbine design and operations and presented a quantitative method for initial site evaluation. The 2003 guidelines were not widely used and the 2011 guidelines will replace them.
Methods Surveys for Golden Eagle and Ferruginous Hawk activity were conducted at the Boswell Springs site from late April through August 2011 (Table 1), coinciding with the expected breeding and fledging periods for these species. Observations were conducted once in April, and twice during each subsequent month through August (Table 2). Observations consisted of three 2-hour survey periods at each point on each visit. Surveys were conducted at three points (Map Exhibit 1 & 2) located to provide clear and distant views of the site near known nests of Ferruginous Hawk and Golden Eagle, and to view as much of the site as possible. One point was located in the northeastern portion of the site approximately one mile northeast of an active Ferruginous Hawk nest. Two locations were in the western portion of the site. The southwestern point was
located near a Golden Eagle nest known to be active in 2010, and presumed to be active in 2011. The northwestern point was located near a nest identified as unoccupied in 2010 and presumed to be an unoccupied eagle nest. In 2011 this nest was actively used by a pair of Ferruginous Hawks. Viewsheds from each point (Table 1) are shown on Map Exhibits 1 & 2. The three viewsheds combined represented 67% of the total site area. Views from the southwestern point were partially blocked by the elevation changes. Activity within the drainage itself could not be observed to the northeast; however the sky above this area was clearly visible.
Table 1. Hours of observation and viewshed areas at the Boswell Springs site Location Total Hours of Viewshed (km2) Viewshed within Project Observation Footprint (km2) Northeast 53.8 84 24 Northwest 54.0 25 11 Southwest 54.0 45 25
Table 2. Survey dates and weather conditions at the Boswell Springs site Month Dates General Conditions Chilly and windy. Temps ranged from 35 to 45 degrees with April 28 and 29 winds 10 to 20 mph. Snowfall by end of survey, limiting visibility. Mild and windy. Temps ranged from 40 to 70 degrees. Calm May 7 and 8 in early a.m. and then windy. Cool, variable winds. Temps ranged from 35 to 55 and winds 24 and 25 from calm in the morning to 20 mph. Some light rain during the survey. Mild temperatures from 40 to 70 degrees but very breezy June 7 and 8 except in the early morning. Calm in the morning but winds up to 30 mph in the afternoon. Mild temperatures with low of 39 early in the a.m. and then 21 and 22 up to 70 during day. Breezy with winds up to 20 mph. Pleasant temperatures from 55 to 75 degrees with breeze up July 8 and 9 to 15 mph. Mosquitoes plentiful. Mild temperatures from 55 to 75 degrees. Winds calm early 26 and 27 and late but up to 20 mph in middle of the day. Some light rain. Mild to hot with temperatures from 55 to 85 degrees. Winds August 4 and 5 mild, up to 10 mph in middle of the day. Mild in the morning at 50 degrees to a warm 80 degrees in 16 and 17 the middle of the day. Calm in morning with breeze at 15 mph in the middle of the day.
The viewshed at each point was divided into a grid of ½ by ½ mile cells to facilitate the mapping of flight paths. For each observation data recorded were: all eagles or Ferruginous Hawks observed, grid cell, flight behavior, distance and direction from the observer, and weather conditions. The flight origin direction and flight direction from the survey point, the flight height and time of observation were recorded. Estimates of flight heights were based on comparison with known heights of existing objects. Survey data were entered into an Access database for storage and analysis.
Survey time of day varied at each point between dawn and dusk. Surveys were not performed in steady rain, fog, or steady winds over 25mph. Observations were made from within a parked vehicle in order to minimize disturbance due to presence at the site. Minutes of observed flight time were assigned to each individual gird cell observation. A perched bird not observed to leave its perch was assigned 1 minute of flight time within the grid cell. Minutes of flight time were totaled by grid cell separately for Golden Eagle and Ferruginous Hawk. Minutes of flight time were totaled for each viewshed and the minutes of flight time per minutes of observation at the point per unit area was calculated.
Results & Discussion
Golden Eagle Golden Eagles were observed from all three observation points (Table 3). From the northeast point Golden Eagle observations were rare. Most observations occurred off-site near the Wheatland Reservoir. Eagles flying near the reservoir were observed flying over the southern portion of the site on two occasions. One of these observations consisted of a single eagle, and the second of two eagles. An eagle was also observed flying off-site to the north of the site. At the northwest point observations also were rare. Eagle activity was slightly more frequent off-site to the north of the site, but even at that location few observations of eagles were made. The greatest Golden Eagle activity occurred at the southwest point, as expected due to the proximity of an active nest southwest of the site. The nest was known to be active in 2010. Nesting status in 2011 was not determined. The greatest activity from this presumed nest occurred northeast of the observation point along the escarpment paralleling Seven Mile Creek. About three-quarters of all observations occurred in an east- west corridor more or less parallel to Seven Mile Creek. The corridor was about a mile wide and extended eastward into the site for about 2.5 miles. There were few observations along the south edge of the project despite the fact that this area lies between Seven Mile Creek and active nest. This pattern of activity suggests that this eagle pair has a strong orientation to Seven Mile Creek and the adjacent area, perhaps using it as a travel corridor which connects to the Rock River where the nest is. The greater presence of eagles along the escarpment in the vicinity of Seven Mile Creek may be associated with favorable wind patterns at that location (west to south slopes with updrafts), or favorable foraging grounds in that vicinity, or a flight path to and from foraging grounds, or a combination of these factors. Whatever the case, this location appears to comprise a use area for the pair of eagles nesting to the southwest. Other locations in the project boundary are not regularly used, although occasionally eagles pass through those areas.
Table 3. Flight observations at the Boswell Springs Site Location Golden Eagle Ferruginous Hawk Flight Minutes Flight Minutes/Minutes Flight Minutes Flight Minutes/Minutes of Observed on Site of Observation/km2 Observed on Site Observation/km2 Northeast 8 0.0001 579 0.01 Northwest 4 0.0001 20 0.0001 Southwest 211 0.003 1 0.00001
Ferruginous Hawk Ferruginous Hawks were also observed from all observation points (Table 3), although only one flight was observed from the southwest point. This flight occurred just north of the observation point. The northwest point also had a low level of Ferruginous Hawk activity. The greatest activity was observed off-site near the active nest and to the north of the observation point, north and east of the nest. As mentioned, this nest was
identified in 2010 as a possible unoccupied Golden Eagle nest. In 2011 it was occupied by a pair of Ferruginous Hawks. The greatest Ferruginous Hawk activity was recorded from the northeastern observation point. An active Ferruginous Hawk nest was located southwest of the point. About three-quarters of all observations occurred within 0.5 miles of the nest. Nearly all observations were within 1 mile of the nest. Most of the observed activity was from the nesting pair associated with this nest. Occasionally three Ferruginous Hawks were observed flying together. It is likely that there is another nest north of the site, and individuals may have been involved in territorial defense.
Additional Observations Two additional unoccupied nest sites were identified in 2011 within the project site. One nest site just east of the southwestern observation point has a large stick nest in a tree with a second nest below. These nests are likely to be unoccupied Golden Eagle nests. The second nest site is located on a windmill just west of the northwestern observation point. This nest is in poor condition. During field surveys spotlighting for Black-footed Ferret (Mustela nigripes) was observed south and west of the site, in or near the southwest corner of the site. Black-footed Ferret were introduced into the Shirley Basin in 1991. It is believed that the current abundance of this population is above 200 individuals, and it may extend as far east as Wheatland Reservoir No. 3 (A. Travsky, personal communication). This population is a nonessential experimental population (NEP) under section 10(j) of the ESA, as amended (USFWS 1991). As a NEP, the Black-footed Ferret is regulated as a Threatened, not Endangered Species. In addition, normal rules pertaining to Federal Threatened species may be modified by the USFWS. In the case of this NEP, individuals and corporations will be exempt from prosecution for accidental or incidental takings during the course of otherwise lawful activities. Two Mountain Plovers were observed on April 29th in the southwestern portion of the site near the southwestern observation point. This was during the spring migration. They were not observed again on the site. Mountain Plover is currently a candidate for listing under the ESA. Mountain Plover have been sought but not observed in previous surveys. Two bull Elk were observed near the center of the site on June 7th.
Applications and Next Steps The observation data on Bald Eagle and Ferruginous Hawk at the Boswell Springs wind project can be interpreted as follows. Eagle activity was greatest in the vicinity of an active eagle nest off-site to the southwest and Ferruginous Hawk activity was greatest around an active nest in the northeast portion of the site. Eagle and hawk activity was rare to non-existent over the remainder of the site. In addition, eagle and hawk activity exhibited an inverse relationship—where eagle activity was high, hawk activity was very low, and where hawk activity was high, eagle activity was very low. Nearly three-quarters of Ferruginous Hawk activity in the northeast part of the site occurred within 0.5 miles of the nest, and nearly all activity occurred within 1 mile of that nest. Three-quarters of the Bald Eagle activity occurred within 1 mile of Seven Mile Creek. These two locations appear to pose a significantly higher risk to eagles and Ferruginous Hawks than the remainder of the site. Future activity related to eagles and hawks at Boswell Springs could consist of the following: 1. Discuss the findings of this study with USFWS and Wyoming Game and Fish (WYG&F). 2. Use the data on eagle use of the site in the USFWS eagle mortality model and predict expected mortality at the site. Use this outcome to decide on future steps, including implementation of advanced conservation practices (ACPs) as described in the eagle conservation planning guidance. 3. Decide on a process of engaging with USFWS and WYG&F in order to determine whether an eagle programmatic take permit is likely to be required for the site. Also discuss implications of Ferruginous Hawk
use of the site. Because the species is not threatened or endangered, it is not covered by the federal or state endangered species laws; this is likely to consist of a set-back requirement. 4. If warranted, in the two years prior to construction, complete a second season of surveys for Golden Eagle and Ferruginous Hawk. 5. If warranted, combine the two years of survey data and re-run the eagle mortality model. Decide on ACPs to reduce or eliminate eagle. Decide on how to approach the USFWS and WYG&F regarding likelihood of requiring a programmatic take permit for eagles. 6. Lay out a plan and budget for obtaining a programmatic take permit for Golden Eagle, if required.
Literature Cited USFWS (US Fish and Wildlife Service). 1991. Endangered and threatened wildlife and plants: establishment of a nonessential experimental population of Black-footed Ferrets in southeastern Wyoming. Federal Register 56(162):41473-41489. USFWS – Wind Turbine Guidelines Advisory Committee. 2003. Interim guidelines to avoid and minimize wildlife impacts from wind turbines. Washington, DC. USFWS Wind Turbine Guidelines Advisory Committee – Legal Subcommittee. 2008. Legal White Paper. http://www.fws.gov/habitatconservation/windpower/Subcommittee/Legal/Reports/Wind_Turbin e_Advisory_Committee_Legal_Subcommittee_White_Paper_(Final_As_Posted).pdf (Accessed 2008). USFWS. 2009. Eagle permits; take necessary to protect interests in particular localities; final rules. Federal Register. 50CRF Parts 13 and 22. USFWS. 2011a. U.S. Fish and Wildlife Service Draft Land-based wind energy guidelines. http://www.fws.gov/windenergy/docs/Wind_Energy_Guidelines_2_15_2011FINAL.pdf (Accessed 2011). USFWS. 2011b. Draft eagle conservation plan guidance. Washington, DC. http://www.fws.gov/windenergy/docs/ECP_draft_guidance_2_10_final_clean_omb.pdf (Accessed 2011). USFWS. 2011c. U.S. Fish and Wildlife Service Draft Land-based wind energy guidelines. http://www.fws.gov/windenergy/docs/WEG_September_13_2011.pdf (Accessed 2011).
Map Exhibit 1. Golden Eagle Monitoring Locations and Minutes Observed
Map Exhibit 2. Ferruginous Hawk Monitoring Locations and Minutes Observed
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm ALBANY COUNTY, WYOMING
Submitted to: Mr. Paul Martin, Intermountain Wind PO Box 353 Boulder, CO 80306
Prepared by: Heather Kieweg, Doug Mensing and Kim Chapman Applied Ecological Services, Inc. 21938 Mushtown Road, Prior Lake, Minnesota 55372 Phone: (952) 447-1919, Fax: (952) 447-1920 Email: [email protected]
March 15, 2011
AES # 08-0853 AES # 08-0853
TABLE OF CONTENTS
1. Introduction ...... 1 1.1. Project Description ...... 1 1.2. Wildlife and Habitat at Boswell Springs Wind Farm ...... 1 1.3. Wind Development Regulations and Guidance ...... 2 1.3.1. Endangered and Threatened Species ...... 2 1.3.2. Bald and Golden Eagle Protection Act...... 2 1.3.3. Migratory Bird Treaty Act ...... 2 1.3.4. Bats ...... 2 1.3.5. Wind Development Guidance ...... 2 1.3.6. Other Regulations ...... 3 1.4. Communications with Wildlife Agencies ...... 3 2. Study Approach and Methods ...... 4 2.1. Recommended Biological Surveys, Studies and Mapping ...... 4 2.2. Habitat Cover Mapping & Point Selection ...... 6 2.3. Endangered and Threatened Species ...... 7 2.4. Bald and Golden Eagles ...... 7 2.5. Native and Sensitive Bird Species ...... 7 2.5.1. Field Methods ...... 8 2.5.2. Data Analysis ...... 10 2.6. Bats and Collision Risk ...... 11 2.7. Species of Greatest Conservation Need ...... 12 2.7.1. White-tailed Prairie Dog ...... 12 3. Results and Discussion ...... 12 3.1. Habitat ...... 12 3.2. Endangered and Threatened Species ...... 13 3.2.1. Mountain Plover ...... 13 3.2.2 Black-footed Ferret ...... 14 3.3. Bald and Golden Eagles ...... 14 3.4. Native and Sensitive Bird Species ...... 15 3.4.1. Collision Risk ...... 15 3.4.2. Habitat Displacement Risk ...... 21 3.5. Bat Habitat Based Risk Analysis ...... 22 3.6. Species of Greatest Conservation Need ...... 24 3.6.1. McCown’s Longspur ...... 24 3.6.2. Brewer’s Sparrow ...... 24 3.6.3. Ferruginous Hawk ...... 25 3.6.4. Lark Bunting ...... 25 3.6.5. White-tailed Prairie Dogs ...... 26 3.6.6. Amphibians and Reptiles ...... 26 3.6.7. Swift Fox ...... 26 4. Summary of Effects and Recommendations to Reduce Impacts ...... 28 4.1. Endangered and Threatened Species ...... 28 4.2. Bald and Golden Eagles ...... 28 4.3. Native and Sensitive Bird Species ...... 28 4.3.1. Native, Sensitive and Long-distance Migrant Bird Species Collision Risk ...... 28 4.3.2 Habitat Displacement Risk ...... 29 4.4. Bats and Collision Risk ...... 29 4.5. Species of Greatest Conservation Need ...... 29 5. Literature Cited ...... 30
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm i
TABLES Table 1. WYGF & USFWS Recommended Biological Surveys, Studies and Mapping...... 4 Table 2. AES habitat cover type descriptions...... 6 Table 3. Habitat types, number of sampling points (P) and number of surveys (N) by survey type for the first study season...... 7 Table 4. Dates of bird surveys at Boswell Springs...... 9 Table 6. Land Cover at proposed Boswell Springs site...... 13 Table 7. Native, sensitive, and long-distance migrant mean abundance and mean richness by habitat on-site during spring and fall passerine migration and breeding bird surveys1...... 17 Table 8. Native, sensitive, and long-distance migrant mean abundance and mean richness on-site and in reference area during fall passerine migration surveys...... 17 Table 9. Raptor abundance by survey...... 20 Table 10. Bat habitat-based risk analysis...... 23 Table 11. Amphibian and reptile habitat-based risk analysis...... 27
MAP EXHIBITS Map Exhibit 1. Site Location & Survey Points Map Exhibit 2. Site Habitats Map Exhibit 3. Winter Bird Locations Map Exhibit 4. Raptor Nest Locations Map Exhibit 5. Interpreted Prairie Dog Population Density Map Exhibit 6. Sensitive Areas
APPENDICES APPENDIX 1. SITE REVIEW APPENDIX 2. PER-POINT ABUNDANCE OF BIRDS SURVEYED DURING ALL POINT-COUNT SURVEYS ON SITE APPENDIX 3. PER-POINT ABUNDANCE OF BIRDS SURVEYED DURING FALL PASSERINE AND FALL RAPTOR SURVEYS APPENDIX 5 . USFWS SITE DEVELOPMENT AND CONSTRUCTION BEST MANAGEMENT PRACTICES (USFWS – WIND TURBINE GUIDELINES ADVISORY COMMITTEE 2010b) APPENDIX 6. WIND ENERGY DEVELOPMENT: BEST PRACTICES FOR MIGRATORY BIRDS (USFWS – ECOLOGICAL SERVICES 2010a)
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm ii EXECUTIVE SUMMARY The proposed Boswell Springs Wind Farm and associated phases (“site”) constitutes about 34 square miles of primarily Grassland and Upland shrub-scrub habitat. Elevations range from 6,713 to 7,192 feet, in the Rolling Sagebrush Steppe of the Wyoming Basin. Wetlands primarily follow riparian corridors throughout the site and a few reservoirs of open water occur along Seven-Mile Creek and Spring Creek. The topography is generally flat except for along the watercourses where it descends 60 to 80 feet. Preliminary plans are for 80-100m high turbines with 77-90m diameter blades. AES communicated with the Wyoming Game and Fish Department (WGFD) and U.S. Fish and Wildlife Service (USFWS) and to develop biological surveys that would characterize risks to wildlife at the site from wind development. Issues of concern included migrating passerines and raptors, breeding birds, Sage Grouse, bats, amphibians and reptiles, White-tailed Prairie Dog distribution and influence of Wheatland Reservoir on the site. AES coordinated methods with the WGFD and USFWS to investigate these concerns. The resulting surveys included a spring passerine survey, a spring raptor survey, a breeding bird survey, a fall passerine survey, a fall raptor survey, a winter bird survey, an aerial raptor nest search and nest monitoring, Sage Grouse lek surveys, bat habitat analysis, bat acoustic monitoring, analysis of Species of Greatest Conservation Need, amphibian and reptile habitat analysis, amphibian and reptile incidental observations, priority watershed mapping, White- tailed Prairie Dog concentration mapping and observations at Wheatland Reservoir. The bird surveys were conducted from April 2009 to April 2010. The bat acoustic monitoring is ongoing and results will be reported in an addendum to this report. Surveys in fall 2010 were paired with surveys in a reference area, which will be used as a control after construction. A second season of surveys will be completed prior to construction in order to validate the preliminary results reported here. Mountain Plover have been recently proposed for listing as a threatened species. There are historic records from the 1990’s on the site along Fetterman Road. No Mountain Plovers were found during the three survey periods conducted during the recommended search period, however no Mountain Plover specific surveys following USFWS survey protocol have been completed, and it is possible that Mountain Plover may be present at the site, but undetected. Golden Eagles were sighted on the site in the spring migration, breeding bird and fall migration surveys. Golden Eagles were found nesting 1.5 miles southwest of the site, and two additional nests that were unoccupied at the time of the survey were found near the site. Golden Eagle distribution did not correlate with White-tailed Prairie Dog distribution. Bald Eagles were observed twice during the fall migration. Given the lack of Golden Eagle mortality at the nearby Foote Creek Rim (FCR) facility and the limited use of the site by Bald Eagles collision risk for these species is very low. Passerine migrants were counted at 25 survey points in spring, breeding season and fall. Raptors were counted at 6 survey points in the spring and the fall. In all point count surveys, 42 different species were observed on site, and an additional species was observed in the reference area. Of the species seen on site 18 (43%) were classed as sensitive species (species at risk due to existing factors), and the additional species seen in the reference area was considered sensitive. This number is higher than expected and is due to the presence of species which are in decline regionally, but common elsewhere in their range (e.g., Mallard, Barn Swallow and Northern Shoveler). The most commonly observed species throughout the site, constituting 70% of individuals seen, were Horned Lark, Mallard, McCown’s Longspur, Blue-winged Teal, Green-winged Teal, Northern Shoveler, Gadwall, Western Meadowlark, Violet-green Swallow and Vesper Sparrow. The greatest abundance and richness of native birds, sensitive species and long-distance migrants (i.e., “neotropical migrants”) occurred at wetland points in riparian corridors. The Grassland and Upland shrub-scrub points had a significantly lower abundance and richness of native bird species, long- distance migrants, and significantly lower richness of sensitive species. Sensitive species abundance was lower at Grassland and Upland shrub-scrub points, but the difference was not significant.
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm iii
Raptors were present in low abundance at the site throughout the year. On average, 1.67 raptors were recorded per hour of observation. The site does not appear to be a raptor concentration area, but on some days the site may experience an elevated raptor passage rate as a broad front of raptors passes through the area. The most common raptor species on the site were Golden Eagle, Ferruginous Hawk and Northern Harrier. Golden Eagle and Ferruginous Hawk are both raptor species of concern to the USFWS. Two nests that are probably Red-tailed Hawk nests, one nest on a ledge that is possibly a Ferruginous Hawk nest and a possible nest on a structure were found on the site during the aerial survey. All of these nests were unoccupied at the time of the survey. In the reference area there are nests and possible nests of Golden Eagle, Ferruginous Hawk, Red-tailed Hawk and Swainson ’s Hawk. Two species, Vesper Sparrow and Northern Harrier, thought to be potentially sensitive to habitat displacement from wind development were found. These species are not declining in the BBS region nor are they SGCN species. Area sensitivity has not been studied for the McCown’s Longspur which is an SGCN species and abundant on the site in all habitats. The rarer Lark Bunting, also an SGCN species, may be area sensitive. Placement of turbines may result in shifting of territories or a reduction of nesting density for these species. No signs of Sage Grouse were observed during the 2009 grouse surveys, and all historical lek locations were unoccupied at the time of the surveys. The site lies outside the designated Sage Grouse Core Areas. Bat habitat risk analysis identified Big Brown Bat, Fringed Myotis and Western Small-footed Myotis as the species most likely to occur on the site. None of these species are known to be particularly sensitive to wind development. Results of ongoing bat acoustic monitoring will provide data on the site’s bat community and be included as an addendum to this report. Nine bird Species of Greatest Conservation Need (SGCN) were observed on the site. These species do not have a protected legal status, but it is recommended that impacts to these species be avoided or mitigated where possible. Of the nine species McCown’s Longspur, Brewer’s Sparrow, Ferruginous Hawk and Lark Bunting were likely to be breeding on the site. McCown’s Longspur was common on the site, and has the potential for direct collision mortality due to its sky-larking territorial displays, although these are typically below the rotor swept area. To date Boreal Chorus Frogs are the only species of amphibians and reptiles confirmed on the site. Amphibian and reptile species that are likely to use the Grassland and Upland shrub-scrub communities include Bullsnake, Greater Short-horned Lizard and Prairie Rattlesnake. Incidental observations for these species will continue to be made through October 2010. White-tailed Prairie Dogs were located in grasslands throughout the site. Prairie dogs were densest in grassland areas and least dense in Upland shrub-scrub habitats and along riparian corridors. Prairie dog density did not correspond to raptor abundance. Given these findings, specific recommendations focus on avoiding known sensitive areas, particularly wetlands along riparian corridors and wetlands over 5 acres in size. Possible presence of Mountain Plover at the site should be discussed with USFWS. Management concerns for the Golden Eagle and Ferruginous Hawk should be discussed with the USFWS and WGFD. Concerns for SGCN species—McCown’s Longspur, Brewer’s Sparrow, Ferruginous Hawk, Lark Bunting—should be discussed with the WGFD. Post-construction mortality surveys should be conducted for birds and bats, and post-construction point count surveys completed to document density changes of Vesper Sparrow and McCown’s Longspur using the BACI approach. Other general recommendations for wind farm design and operation are provided based on federal and state guidance. These recommendations will be reassessed after the completion of a second year of studies prior to the construction of the wind farm.
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm iv
ACKNOWLEDGEMENTS Intermountain Wind and Applied Ecological Services thank Scott Gamo, John Emmerich, Matt Fry and Mary Flanderka of the Wyoming Game and Fish Department for their guidance in using the Wyoming survey protocols and refining the survey methods used in the field. Scott Covington and Patricia Sweanor of the USFWS were very helpful in developing the raptor nest search and observation approach, as well as in identifying their issues of concern. We also thank Amber Travsky of Real West Natural Resource Consulting and Caitlin Coberly of Merlin Environmental, LLC, who contributed significantly to this study through their extensive field work.
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm v 1. Introduction Intermountain Wind retained Applied Ecological Services, Inc. (AES) to provide site review and biological surveys for a potential wind farm in central Albany County, Wyoming (Map Exhibit 1). In spring 2009, AES completed a Site Review for the site, which detailed potential issues and survey requirements (Appendix 1). AES conducted a season of biological surveys at the site from spring 2009 through Spring 2010. A second season of surveys will be completed prior to construction of the wind farm. This report summarizes methods and results of the first season’s biological surveys, discusses the implications of these surveys for the development of the wind farm site, and provides recommendations for avoiding and minimizing biological impacts. 1.1. Project Description The proposed Boswell Springs Wind Farm (the “site”) is an approximately 34 sq mi area located 40 miles northwest of Laramie, Wyoming (Map Exhibit 1). Design specifications for the wind turbines have not been completed. The turbines are expected to be 1-2 MW, with tower heights of 80-100m and rotors of approximately 77-90m diameter. Based on these dimensions, the upper limit of the rotor swept area (RSA) would be 118m to 145m, and the lower limit of the RSA would be from 35m to 62m. 1.2. Wildlife and Habitat at Boswell Springs Wind Farm The site is located in the Rolling Sagebrush Steppe of the Wyoming Basin. The basin is a broad intermontane region dominated by grasslands and shrublands that often are big sagebrush shrublands. Precipitation averages from 6 to 16 inches per year. The topography consists of rolling plains, with hills, cuestas, mesas and terraces. The site is relatively flat, but a westward-flowing watercourse descends 60 to 80 feet through the center of the site along Seven-mile Creek and to a lesser extent Spring Creek. Elevations range from 6,713 to 7,192ft (2,046 to 2,192m). South and east of the site the terrain descends to Rock Creek, and to the northeast of the site the landscape ascends and transitions into foothills of the Laramie Mountains. Sagebrush still dominates most of the region, but invasive European annual grasses are replacing sagebrush in some areas (Chapman et al. 2004). The site itself is dominated by grassland with pockets of high quality sagebrush in the northwestern and northeastern portions of the site. Riparian emergent wetlands occur along Seven-mile Creek and Spring Creek, and isolated emergent wetlands are scattered throughout the site. There are a few small reservoirs with open water along these creek corridors. While there are no large bodies of open water within the site, the Wheatland No. 3 Reservoir is located just southeast of the site. Development in the area supports cattle ranching. Stock handling areas, roads and fences, and stock ponds and reservoirs are the main constructed features. Conditions for wildlife are typical of ranching country that contains scattered development. Pronghorn antelope are the most frequently observed large game. The amount of forage available to wildlife on the site is less than would be expected with ungrazed conditions. Consequently, small mammal populations comprising the base of the food chain may be different than with ungrazed conditions. This may affect raptor populations. However, White-tailed Prairie Dogs use the site extensively. Some habitat fragmentation has occurred due to roads and development, but large, continuous habitat blocks remain and are expected to support species that may decrease with habitat fragmentation. Overall, wildlife at the site is representative of the region’s grasslands and shrub-scrub habitats.
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 1
1.3. Wind Development Regulations and Guidance
1.3.1. Endangered and Threatened Species Endangered and Threatened (ET) species are protected at the federal level under the Endangered Species Act (ESA). The federal ESA protects listed species and their habitats. There is a mechanism to grant permission for incidental takings under the ESA. The state of Wyoming only protects federally listed species, and does not maintain a separate state endangered and threatened species list. However, nongame wildlife is protected under WGFD Regulation Chapter 52 Nongame Wildlife.
1.3.2. Bald and Golden Eagle Protection Act The Bald and Golden Eagle Protection Act (BGEPA) assigns legal authority to the U.S. Fish and Wildlife Service (USFWS) to protect Bald and Golden Eagles from takings and disturbance. Rules for the issuance of permits under the BGEPA were finalized on September 11, 2009 (USFWS 2009). Permitted activities do not distinguish between lethal and non-lethal take and activities that affect individual eagles or important eagle use areas are regulated. The BGEPA permitting process limits the number of permits issued for bald eagles under the BGEPA in each region to estimated 5% of annual productivity for the regional population and provides separate provisions for a programmatic take permit versus individual instances of a take. Programmatic take permits are issued for projects that undertake activities that may disturb or otherwise take eagles on an on-going basis and generally incorporate the implementation of Advanced Conservation Practices, the development of Avian Protection Plans or Wildlife Hazard Management Plans as a condition of the permit. In addition, this permit type also requires basic post-activity monitoring. Individual or “one time” take permits are issued for the removal of eagle nests, direct take of individual eagles, and grandfathered incidental take permits issued under Section 7 of the Endangered Species Act.
1.3.3. Migratory Bird Treaty Act The Migratory Bird Treaty Act (MBTA) assigns legal authority to the US Fish and Wildlife Service (USFWS) to protect migratory birds from takings. These migratory birds include over 800 species of raptor, diurnal migrant, and passerine migrant. The MBTA only regulates direct takings, and not habitat modifications. The level of direct taking by a wind energy facility which would invoke prosecution under the MBTA has not been established. There is currently no mechanism to grant permission for incidental takings under the MBTA. The USFWS believes that it has the authority to create a process similar to that developed for the BGEPA under the MBTA, but has not begun to develop the necessary regulations (USFWS 2008b).
1.3.4. Bats At the federal level, bats are only protected if they are listed as endangered or threatened, and no federally protected bat species are expected to use the site. Since 1994 bats have been protected in Wyoming as part of nongame wildlife regulation – chapter 52. All bat species are protected from intentional take unless approved by the WGFD for control measures to address public health or human safety concerns.
1.3.5. Wind Development Guidance Guidance, recommendations and regulations regarding wind project development and wildlife impacts are still being developed and are constantly changing. The USFWS Wind Turbine Guidelines Advisory Committee completed its recommended guidelines to mitigate impacts to wildlife and their habitats related to land-based wind energy facilities on March 4, 2010. These guidelines are now pending approval by the Secretary of the Interior and are expected to be drafted into final recommendations by the USFWS in the near future. These guidelines outline a tiered
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 2
research approach that includes searches of existing literature and data to identify potential issues of concern, field studies to provide additional data where necessary, and post-construction mortality studies to identify and quantify impacts. This guidance document recommends that wind developers voluntarily adhere to these guidelines and communicate with the USFWS as part of their due diligence process in order to avoid, minimize and mitigate impacts to species protected under the BGEPA and MBTA. It also suggests that the USFWS should use its discretion with regard to prosecution under these acts (USFWS 2010b). In 2003 the USFWS published Interim Voluntary Guidelines (USFWS 2003) which outlined recommendations for site and turbine design and operations and presented a quantitative method for initial site evaluation. The 2003 guidelines were not widely used and the 2010 guidelines will replace them. The USFWS guidelines target “species of concern” and “species of habitat concern.” The guidelines define a species of concern as “any species which is listed as an endangered, threatened or candidate species under the Endangered Species Act, is subject to the Migratory Bird Treaty Act or Bald and Golden Eagle Protection Act, or is designated by law, regulation or other formal process for protection and/or management by the relevant agency or other authority, or has been shown to be significantly adversely affected by wind energy development, and ii) is determined to be possibly affected by the project.” It defines species of habitat fragmentation concern as those “whose genetic or demographic viability is reduced by separation of their habitats into smaller blocks, thereby reducing connectivity, and for which habitat fragmentation from a wind development project may create significant barriers to genetic or demographic viability of the affected population.” At the state level, the Wyoming Game and Fish Department (WGFD) have developed state-wide recommendations for wind developments. These recommendations have been published in draft form (WGFD 2010). These recommendations provide guidance on best management practices, baseline data collection and monitoring. While these are only recommendations, the WGFD does make an assessment of impacts to the Wyoming Industrial Siting Council (WISC) as part of the WISC permitting process, and advises wind energy developers regarding surveys and mitigations at wind farms. To date the WGFD has not found unacceptable impacts in proposed wind energy development projects submitted to the WISB. However, WGFD has negotiated with wind energy developers prior to and during the approval process in order to establish a scientifically valid set of baseline data and to avoid and minimize wildlife impacts that might have resulted from specific turbine siting plans.
1.3.6. Other Regulations Additional federal involvement may be triggered through the Clean Water Act (1972), National Historic Preservation Act (1966) and National Environmental Policy Act (NEPA 1969). The US Army Corps of Engineers (USACE) has permitting authority over proposed impacts to federally protected Waters of the United States, including many wetlands. Wetlands are also protected at the state level by the Wyoming Department of Environmental Quality (WYDEQ). Cultural resources are protected at the state level by the State Historic Preservation Office (SHPO) in collaboration with the federal Advisory Council on Historic Preservation. Federal permitting through the USACE or SHPO may trigger NEPA review of a proposed wind project. 1.4. Communications with Wildlife Agencies Initial wildlife concerns identified in an email to Paul Martin from Vern Stetler dated March 21, 2008 identified Antelope crucial winter ranges and occupied and historic sage grouse leks as issues of concern at the site. AES met with Scott Gamo and Matt Fry May 19, 2009 to discuss recommended studies for this site. Initial studies were already underway, and the WGFD was in the process of drafting recommendations for baseline data collection. The first round of AES studies from March-June 2009 was completed as planned simultaneous with the release of the WGFD recommendations, and
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 3
therefore the recommendations could not be fully accommodated, which WGFD acknowledged. From that point forward, WGFD recommended that the survey protocols in the recommendations be followed. AES detailed plans for biological surveys in a letter to Scott Gamo at the WGFD dated August 25, 2009. This letter proposed that the first round of studies be incorporated into the first year of construction monitoring despite differences in protocol from the new WGFD recommendations, and that future work would follow the new WGFD recommendations. The first year of survey work was completed on 2009-2010 and results from these surveys are reported here. The second year of survey work will be completed in the year prior to construction to provide further baseline data for the site. John Emmerich of WGFD responded with comments on October 2, 2009. This letter approved proposed study protocols with the request for further coordination on bat survey protocols and additional attention to newly developed water and stream monitoring protocols. In February-March 2010, AES communicated with Scott Covington and Patricia Sweanor of the USFWS regarding raptor nest searching and monitoring protocols. AES’s survey protocols were communicated to the USFWS. In a phone conversation with Scott Gamo of WGFD and Paul Martin (Intermountain Wind) on March 22, 2010, AES further discussed study protocols including bats, wetlands and riparian areas, big game, reptiles and amphibians, and Species of Greatest Conservation Concern. 2. Study Approach and Methods 2.1. Recommended Biological Surveys, Studies and Mapping Table 1 provides the dates and summary descriptions of biological surveys recommended for the site. More detailed methods for selected surveys are provided in the following pages.
Table 1. WYGF & USFWS Recommended Biological Surveys, Studies and Mapping. Survey Dates Description Comments
Federal ET Species – No Studies Required
BGEPA & MBTA Fixed-wing aircraft survey to detect Second year of study to Raptor Nest raptor nests and evidence of raptor April 26, 2010 be completed prior to Search breeding; site and reference area construction surveyed on 0.5 minute transects. Results to be reported in Monitor raptor activity to determine report addendum. Second Raptor Nest June-July 2010 flight paths in the areas of known year of study to be Monitoring nests. completed prior to construction 3 survey periods; 30-minute point count surveys; 9am-4pm; point Second year of study to Spring Raptor April 10,11 & 16, density 1 per 5-7 square miles; be completed prior to Migration Survey May 19, 2009 minimum point separation distance construction 2 miles September 11- Methods follow spring raptor 13, 2009; Second year of study to Fall Raptor migration survey with the addition of October 2-4, be completed prior to Migration Survey 6 reference points outside of the 2009; October construction site. 25-27
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Survey Dates Description Comments
BGEPA & MBTA 10-minute point count surveys conducted from dawn to 11am at 25 Second year of study to Spring Migratory May 19-20, 24- locations; count density of 1 point be completed prior to Passerine Survey 25, 2009 per 1-2 square miles distributed to construction represent habitat types; points separated by a minimum of 250m. 10-minute point counts conducted from dawn to 11am at 25 locations; Second year of study to Breeding Bird June 8 & 11, count density 1 point per 1-2 square be completed prior to Survey 2009 miles, distributed to represent construction. habitat types; points separated by a minimum of 250m. August 29 & 30, Methods follow spring migratory Second year of study to Fall Migratory 2009; September passerine survey with the addition be completed prior to Passerine Survey 11-13, 2009; of 25 reference points outside of the construction. October2-4, 2009 site, and three survey periods. December 15, Driving survey of passable roads on 2009; January Second year of study to site and reference area; all birds Winter Bird Survey 12, 2010; be completed prior to seen or heard recorded and February 23, construction. mapped. 2010 WGFD Regulations & Recommendations Driving surveys at first light on site April 11 & 16, Second year of study to Sage Grouse Lek in sagebrush habitat, particularly 2009 and May 7, be completed prior to Surveys near known lek locations; stops 2009. construction. every half mile. Bat Habitat Assessment of likely habitat use by
Analysis bat species. Results and detailed 1 met tower with a stationary methods to be reported in monitoring unit at 55m, and 8 Bat Acoustic June-October report addendum. Second locations at ground level monitored Monitoring 2010 year of study to be for 3 weeks each during the growing completed prior to season. construction. Evaluate site use by SGCN species SGCN analysis with particular attention to and Amphibian amphibians and reptiles including and Reptile Habitat mapping of potential habitat for Analysis these species Amphibian and All incidental observations of June-October, Results to be reported in Reptile Incidental amphibians and reptiles to be 2010 report addendum Observations reported. Mapping to assess whether or not Priority Watershed site is located within a priority Analysis watershed Use aerial photo analysis combined White-tailed Prairie with field verification to identify Dog concentration June 2010 areas of high-, medium- and low- mapping density White-tailed Prairie Dog populations. Wheatland Monitor activity and flight patterns Results to be reported in Reservoir June-July 2010 near Wheatland No. 3 Reservoir report addendum Observations
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2.2. Habitat Cover Mapping & Point Selection A habitat cover map was created to define, visualize and predict the locations where different wildlife communities were present (Map Exhibit 2). Base data were obtained from the NRCS National Land Cover Database – NLCD 2001 (USGS 2007), which has a resolution of 30x30m. Each NLCD land cover type was assigned to an AES habitat cover type for use in field surveys (Table 2). The raster image was clipped to the site boundary, and areas were calculated for each habitat type. Field observations in 2009 confirmed that the land covers had not significantly changed from 2001 when the aerial survey was completed. Delineation of Upland shrub-scrub and Grassland communities was inaccurate; therefore these two categories were combined in our mapping analysis. The site was compared with WGFD priority watershed data to determine whether the site lay within the state’s designated priority watersheds.
Table 2. AES habitat cover type descriptions. AES Habitat Cover Type Description
Developed Residential, commercial, industrial, and other developed land, including developed green space (e.g., golf-course, city park).
Cropland Regularly cultivated land. Pasture, hay meadow, and fallow field are grasslands.
Barren Land Land with sparse to no vegetation (e.g., mines, landfills, construction sites, sparsely vegetated shores).
Grassland Grass and herbaceous plants cover ≥90% of the ground in uplands.
Upland Shrub-Scrub Shrubs and scrubby or mature trees cover 10-50% of the ground. Includes brush land and savanna with trees and shrubs.
Upland Broadleaf Forest Trees cover ≥50% of the ground. Broadleaf deciduous trees are ≥90% of the tree cover.
Upland Coniferous Forest Trees cover ≥50% of the ground. Coniferous (needle-leaved) trees are ≥90% of the tree cover.
Upland Mixed Forest Trees cover ≥50% of the ground. A mixture of broadleaf and coniferous trees, with each covering <90% of the forest.
Forested Wetland A wetland or lowland flooded area with 50-100% tree cover. Shrub-Scrub Wetland Wetlands with 10-50% cover by shrubs, scrubby and mature trees. Includes savanna with trees and shrubs. Emergent Wetland A wetland with ≥90% cover of herbaceous plants. Open Water Water and sparse to no vegetation cover; rivers, streams, lakes, ponds.
Sample points were selected and classified in the field on the basis of AES habitat cover types. Although mapping data did not accurately distinguish between Grassland and Upland-shrub scrub communities the distinction was clear in the field. Points were located in Grassland and Upland shrub-scrub habitats, and in Emergent wetland and Open water habitats along the site’s riparian corridors. These were the only habitats dominant enough in the landscape to warrant sampling. Due to the strong influence of water in this arid environment, all points with Open water or Emergent wetland at the sampling point were classified as Wetland points.
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Bird sample points were distributed to achieve a geographic representation of the site. Consequently, the dominant land use—Grassland—received a large number of sample points. Upland shrub-scrub and Wetland habitats were adequately sampled for statistical analysis (Table 3, Map Exhibit 2). Additionally, point selection was constrained to areas that could be accessed by passable roads, resulting in limited coverage in some areas. Reference points—used as a control for post-construction data comparisons—were selected off-site along publically accessible roadways in habitats similar to those on the site. The number of off-site reference points was approximately equal to the number of points inside the Boswell Springs wind farm. Because the first study season coincided with the release of the WGFD sampling protocols, reference points are missing for the spring and summer surveys. In the second season, reference points will be sampled in all survey periods.
Table 3. Habitat types, number of sampling points (P) and number of surveys (N) by survey type for the first study season. Passerine Raptor Breeding Passerine Fall - Raptor Fall - P(N) Spring - P(N) Spring - P(N) Bird - P(N) P(N) Habitat On On On Site On Site On Site Reference Reference Site Site Grassland 14 (14) 4 (12) 14 (14) 14 (42) 19 (57) 4 (24) 4 (24) Upland shrub- 6 (6) 1 (3) 6 (6) 6 (18) 6 (18) 1 (6) 2 (12) scrub Wetland 5 (5) 1 (3) 5 (5) 5 (15) 1(6) Total 25 (25) 6 (18) 25 (25) 25 (75) 25 (75) 6 (36) 6 (36)
2.3. Endangered and Threatened Species A request for information was made to the Wyoming Natural Diversity Database (WYNDD) regarding biological issues of concern at the proposed site in 2009. WYNDD responded with e- mailed GIS and summary data on February 20, 2009 (WYNDD 2009). These features of concern were evaluated from the standpoint of potential impacts from the wind farm. 2.4. Bald and Golden Eagles The WYNDD query (WYNDD 2009) was used to identify if there were any existing records of nesting eagles within 5 miles of the site. Eagles and eagle nests were also searched for during spring and fall migration and during an aerial nest search. See below for detailed methods. 2.5. Native and Sensitive Bird Species Impacts to native bird species are of greater concern than to non-native bird species, such as European Starling and House Sparrow which have no legal protection. Impacts to bird species in decline due to existing environmental factors are of particular interest in wind farm impact studies. AES terms these already at-risk birds “sensitive species.” Sensitive species are most likely to experience cumulative impacts from wind energy development due to existing factors unrelated to wind energy development. In its monitoring and analyses, AES biologists use native species as a broad indicator of wind farm impacts and sensitive species as a specific indictor of effects to species at risk from historical or ongoing habitat loss and other impacts. Sensitive species are similar to the species of concern as defined in the USFWS recommendations; however the AES-defined sensitive species emphasize the conservation significance of a species. For
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example, Mourning Dove is protected by the MBTA and some state game laws, but its population is large and at low risk from wind energy development. Consequently, it is a “species of concern” to the USFWS, but not a “sensitive species” in our analysis. Sensitive species vary from ecological region to ecological region, based on the abundance and population trends of species. Bird species at the site were identified as sensitive if they met one of the following conditions: • Endangered, threatened, candidate or special concern on federal lists; • Wyoming Species of Greatest Conservation Need (SGCN) • Birds of Conservation Concern for Region 10, Northern Rockies – U.S. portion only (USFWS 2008a), • Critically endangered, endangered, vulnerable, near threatened in IUCN Red Book; • Known from literature to require large habitat blocks (area-sensitive species); • Significantly declining in USGS Breeding Bird Survey (BBS) data (Sauer et al. 2008); or • Demonstrated to be significantly adversely affected by wind energy development. The BBS declining bird list was derived 1980-2007 bird trend data for ecoregions of the U.S. The site is located in the Wyoming Basin (BBS Region 86). All native birds in this region which were significantly declining and had a relative abundance of <5 birds per route were considered sensitive. A species seen <5 times on a 25-mile BBS route is an uncommon species; those with >5 per BBS route were common; e.g., Red-winged Blackbird, American Robin, Horned Lark. The significance of a decline depended on the quality of the data—number of routes on which a bird was sighted, number of times it was sighted and number of years it was sighted. BBS presents trend significance with a 3-tiered Regional Credibility Measure. For the BBS declining bird analysis a trend was considered significant if the variance in the decline due to sampling error was less than the decline measured in the field. The least credible trends required a decline >5 percent annually to be significant; the moderately credible trends required a decline >3% to be considered significant; and the most credible trends were considered significant regardless of the level of decline. Additionally, we included native birds that were significantly declining in USFWS Region 6 but not significantly increasing in the Wyoming Basin and which had a relative abundance <5 birds per route in the Wyoming Basin. Long-distance migrants are species of birds whose summer breeding grounds and wintering areas are completely separated geographically. They migrate at night. Typically these species breed in North America and winter in Central or South America. Many long-distance migrants are sensitive species, and there is concern about the impacts of wind development on them. Passerine birds account for three-quarters of bird fatalities at wind farms, and half of all passerines killed at wind farms are thought to be nocturnal migrants (Erickson et al. 2001; CEIWEP 2007).
2.5.1. Field Methods In 2009, 179 point count surveys were conducted at the site, and an additional 111 point count surveys were conducted in a reference area near the site. A BACI (Before-After Control-Impact) approach was used after the first season’s breeding bird survey. All second year surveys will be conducting using a BACI approach, with the reference point counts serving as the control. Point- count surveys were conducted during the spring and fall migratory periods and the breeding bird season. An aerial search by fixed-wing aircraft identified raptor nest locations, and raptor nest monitoring gathered data on flight paths. A winter bird survey documented winter bird use on the site. Incidental observations of bird activity were recorded at the Wheatland Reservoir to detect elevated bird use in that vicinity, if it existed, and spillover effects in the adjacent Boswell Springs site. Results of the raptor nest monitoring and the Wheatland Reservoir observations will be reported in an addendum to this report.
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For the fall migration and winter bird surveys, and the raptor nest search, reference areas were located off site in order to provide control data for surveys conducted after turbine construction. These reference areas were in habitats similar to those present on site and are not expected to be impacted by wind development. Reference points were along publicly accessible roads near the wind farm site. We did not sample wetland habitats in the reference areas due to a lack of wetland habitat in the surrounding landscape. However, we adequately sampled the dominant habitats at the Boswell Springs wind farm—Grassland and Upland shrub-scrub—to enable post-construction data comparison at locations where turbines are likely to be located.
2.5.1.1. Spring and Fall Passerine Migration and Breeding Bird Surveys Point count passerine surveys assessed bird community abundance and species richness during the 2009 spring migration, breeding bird and fall migration seasons (Table 4). Passerine birds were surveyed once during the spring migration, once during the breeding season, and at three different time periods during the fall migration. Twenty-five points were located in three habitat types and geographically distributed across the site (Map Exhibit 2, Table 3). An additional twenty-five points were located in the reference area in similar habitats. Points were at a minimum 250 meters apart. This resulted in an overall point density of 1 point per 1-2 square miles.
Table 4. Dates of bird surveys at Boswell Springs. Passerine Bird Raptor Spring Fall Spring Fall Aerial Nest Migration Breeding Migration Winter Migration Migration Search 5/19-5/20, 6/8 & 8/29 & 12/15/2009 4/10- 9/11- 4/26/2010 5/24-5/25/2009 6/11/2009 8/30/2009 4/11/2009 9/13/2009 9/11- 1/12/2010 4/16/2009 10/2- 9/13/2009 10/4/2009 10/2- 2/23/2010 5/19/2009 10/25- 10/4/2009 10/27/2009
Point counts lasted for 10 minutes. Data recorded were: all birds seen and heard in an unlimited radius of the sampling point, number of individuals, behavior, distance and direction from the observer, weather conditions, flight origin direction, flight direction, and flight height. Estimates of flight heights were based on comparison with known heights of existing objects (e.g. power poles, towers, trees). Survey data were entered into an Access database for storage and analysis. Survey times varied with season. In the spring passerine migration surveys began around dawn and lasted until 11am or until a noticeable drop in bird activity. In the breeding season surveys were conducted from around dawn to 10am, or until a noticeable drop in bird activity occurred. The fall passerine migration took place from dawn to dusk. Point counts were not performed in steady rain, with poor visibility, or in steady, strong winds.
2.5.1.2. Spring and Fall Raptor Migration Surveys Raptor surveys were conducted at three different times in both spring and fall migratory periods, with one count conducted during each survey round in the spring and two in the fall (Table 4). Six point count locations with distant, unobstructed views were placed in Grassland or Upland shrub- scrub habitat within the site (Map Exhibit 2, Table 3). An additional six point count locations were placed in similar habitat areas in the reference area. Points were at least 2 miles apart, with a resulting point density of one point per every 5-7 square miles. Raptor point counts lasted 30 minutes. Data collection followed the passerine survey methods above. Raptor surveys were conducted between 9am and 4pm on days when weather was favorable for raptor migration.
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2.5.1.3. Raptor Nest Search & Raptor Nest Monitoring An aerial survey from a fixed wing aircraft flown by France Aviation was conducted on April 26, 2010. The site and a reference area were surveyed on half-minute transects at an elevation of 200 feet. To avoid disturbance, nests were not circled; even if nest status was uncertain. Locations of all raptor activity and confirmed and possible nests were recorded as GPS points. Where feasible, nests were field verified from the ground. Snow made passage difficult. Nests were classed as confirmed nests or possible nests. Confirmed nests were clearly nests. Possible nests were structures that may have been nests but which could not be absolutely confirmed as nests. The confirmed nests were classed as occupied or unoccupied, and the species using the nest identified where known. Unoccupied nests were nests that did not show occupancy at the time of the survey. These nests may have been occupied at other times during the season due to late nesting attempts or could be occupied in future years. Occupied nests, where access was possible, were monitored from the ground to establish information on flight paths. Golden Eagle and Red-tailed Hawk nests known to exist south of the site were not accessible by public roads and therefore were not monitored.
2.5.1.4. Winter Bird Survey A winter bird survey was conducted by driving passable roads within the site and reference area on one day per month in December 2009 and January and February, 2010 (Table 4). The survey route was driven twice on each day. The GPS locations of bird activity were mapped, and the species, abundance, flight behavior, and habitat recorded. The December survey covered 9.9 miles on site, and 14.4 miles within the reference area. The January and February surveys covered the same route as the December survey; however, 5.4 mile of the reference route along a two-track gas line access road that was no longer accessible due to snow, resulting in 4.5 miles surveyed on site, and 14.4 miles surveyed in the reference area.
2.5.1.5. Sage Grouse Lek Survey Surveys for Sage Grouse were conducted on April 11, April 16 and May 7, 2009. Surveys were conducted by driving roads within the survey area, particularly the southern and eastern boundaries where previous sage-grouse sightings had been reported on the Wyoming Natural Diversity Database (WYNDD 2009). The site’s northwest corner was also surveyed because it supported the best sagebrush habitat in the area. Stops were made approximately every half-mile in sagebrush habitat to listen for sounds of grouse. Known historical lek sites on or within two miles of the site were specifically checked (Table5). Surveys were conducted from first light to one hour after sunrise.
Table 5. Historical sage-grouse leks located on or near the Boswell Springs Wind Farm.
Zone & Distance from Lek Name Easting Northing 2008 Status Site
Fetterman 21 13T 439100mE 4636200mN Abandoned/Unoccupied 0.78 mi southeast Fetterman 22 13T 437101mE 4639491mN Abandoned/Unoccupied On site Cordingly 13T 426000mE 4641800mN Unoccupied On site Rock Creek Bend 13T 426700mE 4632000mN Unoccupied 3.5 miles south
2.5.2. Data Analysis Data were analyzed to determine the species present in different habitats and the richness and abundance of native, sensitive and long-distance migrant bird species across habitats. Exploration of the data indicated that the aggregate abundance by habitat was consistent across seasons and therefore data from all survey periods were combined for analysis. The effect of habitat on native and sensitive bird richness and abundance was tested for normality, and then a Kruskal-Wallis ranked ANOVA was completed, with pair wise comparisons using the Kolmogorov-Smirnov method. All
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points that had a Wetland or Open Water component were combined and classified as Wetland points. Wetlands surveyed at the site were exclusively in stream drainages. Although NLCD habitat mapping was inaccurate, differences observed in the field between Grassland and Upland shrub- scrub were notable and they were treated as separate habitats in the analysis. As a way to evaluate the utility of the reference points as a control, a Mann-Whitney rank sum test was performed to detect differences between Grassland and Upland shrub-scrub points on-site and in the reference area during the fall migratory period. There were no reference data available for the other seasons. For SGCN species and select sensitive species, the expected mortality rates were calculated based on existing mortality and abundance data from the Foote Creek Rim (FCR) facility (Young et al. 2003a and Johnson et al. 2000b) and abundance data from the spring passerine and breeding bird surveys at the Boswell Springs site. To determine expected mortality rate at FCR for a given species, we used mortality study turbine- carcass data to calculate the percentage of carcasses of that species out of all the carcasses. Then we used that percentage to calculate the proportion of the total mortality at FCR (1.5 BTY) due to that species. This calculation resulted in an expected mortality rate for that species at FCR. In order to determine the expected mortality rate at Boswell Springs the expected mortality rate from FCR needed to be adjusted for differences in abundance between the two sites. This was done by creating a ratio of the abundance at FCR (Johnson et al. 2000b) and the abundance at Boswell Springs to the expected mortality at FCR and the expected mortality at Boswell Springs. For species for which there were no individuals observed at the FCR facility, birds having similar flight behavior were used to approximate the expected mortality. For instance, the mortality rate of McCown’s Longspur, which was not observed at FCR, was estimated using the average mortality rate of three sparrows present at FCR because the longspur behaves like a sparrow rather than another type of bird, such as a warbler. The effect of the Wheatland Reservoir on nearby habitat was investigated. Three points in grassland habitat (3, 4, 5) located at 0.25-0.75 miles from the reservoir were compared to points in similar habitat farther away. A Mann-Whitney rank sum test was performed to detect differences in species richness and abundance between points near the reservoir and away from it. Data were from the fall passerine migration. Additional observations continue to be made to validate the preliminary findings reported here. 2.6. Bats and Collision Risk A desktop habitat analysis was conducted to assess the species of bats likely to be present on site in each habitat. Bats that use the general geographic area of the site were identified as those present in the site’s “latlong” in the Atlas of Birds, Mammals, Amphibians and Reptiles in Wyoming (Cerovski et al. 2004) or in several surrounding “latlongs”. The habitat requirements and range were assessed for each species, and those that were considered either “breeding possible” or “breeding unlikely” were assigned to the site habitats where they would be expected to occur. The habitat-based analysis used published descriptions of the species habitat requirements and ranges (Cerovski et al. 2004; Bat Conservation International 2009). For a “breeding possible” rating at a site, habitat was present, the site was in the species’ range, and the species was not rare. A rating of “breeding unlikely” meant the species had poor or marginal habitat at the site, was at the edge of its range, or was a rare species. Passive acoustic monitoring for bat activity is being conducted during the 2010 field season. One low monitoring unit is measuring bat activity for three weeks at each of 7 stations selected to represent potential bat habitat at the sites. The detailed methods and results of this survey will be reported in an addendum to this report.
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2.7. Species of Greatest Conservation Need Species of Greatest Conservation Need (SGCN) were identified in the Wyoming Wildlife Action Plan (WGFD 2005) as species requiring special consideration in the face of development, so as to prevent their decline. SGCN species observed on site included amphibians, small mammals and birds. AES consulted with WGFD to determine which of the SGCN species warranted additional study. In addition, the WGFD recommended a desktop habitat analysis for amphibians and reptiles, and the recording of incidental observations for all amphibians and reptiles at the site. To conduct the desktop habitat analysis, AES determined amphibians and reptiles likely to occur in the geographic region from the Atlas of Birds, Mammals, Amphibians and Reptiles in Wyoming (Cerovski et al. 2004). Those likely to occur on site were identified through a habitat-based analysis. The habitat-based analysis used published descriptions of the species habitat requirements and ranges (Cerovski et al. 2004, Nature Serve 2010). Species were considered likely to occur in the geographic region if there were atlas records for the site’s “latlong” or for several neighboring “latlongs”. From this initial list, species were classed as possibly breeding at the site, unlikely to breed at the site, or not present at the site. For “breeding possible,” the site must contain habitat for a species and be within a species’ range, and the species must not be rare. Species classed as “breeding unlikely” had poor or marginal habitat at the site, were at the edge of their range, or were rare. Species were then assigned to the habitats where they might occur on site. Species for which the site was out of range or which lacked appropriate habitat were not included.
2.7.1. White-tailed Prairie Dog White-tailed Prairie Dogs were generally present in grassland habitats on the site. Unlike Black-tailed Prairie Dogs they do not form dense colonies, but rather form dispersed colonies over larger areas. The White-tailed Prairie Dog is an SGCN species, and in addition is raptor prey. In order to determine if prairie dog activity might be influencing raptor presence, White-tailed Prairie Dog density was mapped using aerial photography, and mapping was verified by sampling transects in the field. Initial mapping was done by inspecting NAIP 2009 and BING Maps Web-service Imagery for the density of white dots associated with prairie dog burrows, and then mapping these locations as High, Medium and Low-to-No density areas. The minimum mapping unit was one-half square mile. Ground verification was conducted by sampling four transects in each category, High, Medium and Low-to-No density. Each transect was 100m long and all prairie dog burrows within 10m on either side of the transect were counted as a measure of density. A final map was produced of areas with different prairie dog densities. Prairie dog density was then compared to raptor abundance. 3. Results and Discussion 3.1. Habitat The Boswell Springs wind farm is predominately covered by Grassland and Upland shrub-scrub (sagebrush) habitat (Map Exhibit 2, Table 6). Sagebrush dominates the northwestern and northeastern portions of the property, while Grassland dominates the remaining areas. Seven-mile Creek and Spring Creek drain the center of the site, and Emergent Wetland and Open Water Wetlands are associated with these drainages. While some wetlands in these areas were mapped according to the NLCD classification as Forested wetlands, none of the wetlands on the site were actually forested. The Wheatland No. 3 Reservoir located to the southeast of the site is in a priority watershed as designated by WGFD (2009). This watershed covers a small area in the site’s southeastern corner (Map Exhibit 2)
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Table 6. Land Cover at proposed Boswell Springs site. Land Cover Acres Percent of Site Developed 106 0.49 Barren Land 8 0.03 Grassland and Upland Shrub-Scrub 21,145 97.62 Forested Wetland 119 0.55 Emergent Wetland 280 1.29 Open Water 4.2 0.02
3.2. Endangered and Threatened Species The State of Wyoming affords legal protection to animal and plant species that are listed under the Federal Endangered Species Act. A search of the Wyoming Natural Diversity Database (WYNDD 2009) revealed historic and unconfirmed records of the federally endangered Black-footed Ferret (Mustela nigripes) within 5 miles of the site. The federally threatened Canada Lynx (Lynx canadensis) and Greenback Cutthroat Trout (Oncorhynchus clarkia stomias) are also listed as potentially found near the site. However, the Lynx primarily uses subalpine habitat, and the Greenback Cutthroat Trout is thought to be extirpated from Wyoming. To our knowledge, there are no reports of large mammals, such as Lynx, being impacted by wind farm development. Fish are also unlikely to be impacted by the site so long as erosion is controlled during construction and soils are stabilized after construction. There is little standing water on the site, and fish are unlikely to persist in the site’s shallow stockponds or intermittent streams. The database also has records of the Mountain Plover (Charadrius montanus) along Fetterman Road within the site. The Mountain Plover recently was proposed for listing as a threatened species (USFWS 2010c).
3.2.1. Mountain Plover The Mountain Plover (Charadrius montanus), S2 (state imperiled) and G3 (globally vulnerable), was proposed for listing as a federally threatened species June 28, 2010 (USFWS 2010c). Recently populations have been stable, but historically the population contracted severely. Market hunting may have been one of the initial causes of population decline. Other causes include conversion of short-grass prairie to agricultural land, decline of prairie-dog towns which provided foraging and nesting habitat, and habitat loss in wintering areas (NatureServe 2010). The plover nests in high plains/short grass prairie and areas of short sagebrush. It is often associated with prairie dog towns (Wyoming Natural Diversity Database 2009). Construction, operation or maintenance activities at a wind farm project on the FCR Facility caused a severe reduction in nesting frequency and success of Mountain Plovers (Johnson et al. 2000b). The Biodiversity Alliance recommends avoiding all Mountain Plover nesting habitat (Molver 2008). There are 4 records of Mountain Plovers from several locations along Fetterman Road inside the site from 1991 and 1995. There are also 5 records from a nearby Breeding Bird Survey route from 1990 to 1999, and 14 other records within 5 miles of the site from 1983 to 1998. There are no database records at or near the site from the last ten years. No Mountain Plovers were found during the three survey periods conducted in the May 1 to June 15 period recommended by the USFWS (USFWS 2002). The surveyor was experienced in searching for Mountain Plover and covered the area of suitable plover habitat extensively during each survey period. However, the USFWS survey protocol was not used. It is possible that Mountain Plover were present but undetected at the site.
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3.2.2 Black-footed Ferret The Black-footed Ferret (Mustela nigripes) is state ranked S1 (critically imperiled) and critically imperiled globally as well. It is a federally endangered species. The species was extirpated across most of its range through prairie dog and predator control programs. A major obstacle to its re- introduction and recovery is the species’ susceptibility to sylvatic plague. The ferret is associated with prairie dog colonies in Grassland. White-tailed Prairie Dogs, one of the ferret’s prey species, are present throughout the site (Map Exhibit 5). Historic occurrences are reported by the Wyoming Natural Diversity Database (2009) from two vague historic 1960-era records for locations within 5 miles of the site. Habitat is present at the site, but no records of ferrets at the site exist. The Shirley Basin Black-footed Ferret Recovery Area boundary is located approximately 3 miles west of the site—although the release site is significantly to the northwest—and it is possible that the ferret could appear at the wind farm in the future. At this time Black-footed Ferret has not been seen at the site. If the ferret should appear in the future, the effect of the wind farm project on the pattern of colonization and use of the site by ferrets cannot be known. 3.3. Bald and Golden Eagles Bald and Golden Eagles (Haliaeetus leucocephalus, Aquila chrysaetos) are protected by the BGEPA. The Wyoming Natural Diversity Database (WYNDD 2009) has records for both Bald and Golden Eagles on the site and within 5 miles of the site. Both Bald and Golden Eagles were sighted during the ground surveys. During the aerial surveys Golden Eagles were found nesting one and one-half miles southwest of the site in an aspen tree. One eagle was present at the nest. There were no signs of eggs. An additional Golden Eagle nest, unoccupied at the time of the survey, was found just northwest of the site (Map Exhibit 4). Bald Eagles were observed twice on the site during the fall migration at points 2 and 21 (Map Exhibit 1), and two birds were observed in the reference area during the aerial survey. Golden Eagles were observed 33 times on the site (5 during spring surveys, 1 during breeding bird survey, and 22 during fall surveys) and 23 times in the reference area (18 during the fall and 5 during the winter bird surveys (Map Exhibit 3)). The one sighting during the breeding season was at point 25 in the southern portion of the site within 5 miles of the known nesting location. During the spring and fall migrations Golden Eagle sightings were distributed across the site with no particular pattern to the observations. The distribution of eagle sightings did not correlate with abundance of White-tailed Prairie Dogs. Golden Eagles have a broad habitat association, utilizing open country that includes deserts, grasslands, savannas and woodlands. They nest on cliffs or ledges, or in large trees. Nesting habitat is available near Boswell Springs in stream drainages and areas of broken topography, and foraging habitat exists throughout the site. Golden Eagles experienced high mortality at the Altamont Wind Farm (Smallwood and Thelander 2008) where a thousand turbines were placed in densely populated hunting and migration areas. Since then, turbine design has changed dramatically, reducing the number of raptor kills. Taller towers put the rotor-swept area above usual hunting elevations. Solid tubular support towers do not provide the perching opportunities previously implicated in raptor mortality. Fewer and larger blades appear to be easier to see and do not have the “smear” associated with older turbine construction. In addition, wind farm developers are more aware of the importance of siting wind turbines away from raptor concentration associated with migration and foraging. For comparison, data on Golden Eagles from the FCR facility were used. FCR is located 25 miles southwest of the Boswell site in similar habitat, although the terrain is considerably hillier with less wide open space, and there is more surrounding forest cover. There were no Golden Eagles killed at the FCR I facility from 1998 to 2002 (Young et al. 2003a) despite a consistent presence of Golden
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 14
Eagles at the site; however one Golden Eagle carcass was found at the FCR II and III facilities in a 1.5 year study (Young et al 2003b). At FCR, Golden Eagles had an abundance of 0.62 birds/survey in the spring, 0.48 birds/survey in summer, 0.70 birds/survey in fall, and 0.34 birds/survey in winter (Johnson 2000b). By comparison, Golden Eagles were present at Boswell with 0.22 birds/survey in the spring raptor surveys, 0.04 birds/survey in the breeding bird survey, and 0.44 birds/survey during fall raptor surveys. The density of Golden Eagles in migration and the breeding period is consistently lower than that at FCR. Considering the limited Golden Eagle mortality during four years of monitoring at the FCR facility (0.3 Golden Eagles per 100,000m2 RSA) (Young et al. 2003b) and the lower density at the Boswell site, the risk of collision is very low. Likewise, the limited use of the Boswell site by Bald Eagles suggests a very low collision risk for that species. Data from the second season of surveys will be used to validate this preliminary finding. 3.4. Native and Sensitive Bird Species The intent of AES’s general research on birds was to describe the distribution and abundance of native, sensitive and long-distance migrant bird species at different locations in the site so that decisions to use or avoid different areas could be made. AES observed 42 different species of birds on-site during the spring and fall migratory surveys (raptor and passerine) and the breeding bird survey (Appendix 2), and one species, Loggerhead Shrike, incidentally between survey points. During the fall migratory survey period 30 species were observed on site and 11 species were observed at the reference points (Appendix 3). One species observed in the reference area, American Coot, was not observed on site. All these species are considered native to the area and no non-native species were recorded. Of the 42 native bird species seen in point count surveys on the site, 18 (43%) were classified as sensitive species by criteria described above. Of these 18 sensitive species, 7 are experiencing declining abundance as indicated in Breeding Bird Survey data, and 9 species were derived primarily from lists of species of concern, including Wyoming Species of Greatest Conservation Need (WGFD 2005) and Birds of Conservation Concern (USFWS 2008a). The other two species, Northern Harrier and Vesper Sparrow, were classified as sensitive because they respond negatively to habitat fragmentation. The sensitive species list includes three BBS declining species which are otherwise common elsewhere in their range including: Barn Swallow, Mallard and Northern Shoveler. Loggerhead Shrike is also considered sensitive due to its presence on the Birds of Conservation Concern List, and American Coot (seen only in the reference area) is considered a sensitive species because it is declining in the region. Sensitive species have the greatest need for conservation action given their population status and trends and their habitat requirements. Because long-distance migrants are especially susceptible to collision risk, AES analyzed these species separately. Ten (23%) of the species observed were classified as long-distance migrant species. Native species, sensitive species and long-distance migrants are treated separately in the analysis below.
3.4.1. Collision Risk Death by collision is the most apparent risk to native and sensitive birds. Recent studies suggest that bird behavior is a stronger predictor of collision risk than other factors, such as observed flight height or local abundance (de Lucas et al. 2008, Smallwood et al. 2009). However, habitat is important in predicting the location of species. As a result, avoiding habitats supporting concentrations of native and sensitive bird species reduces collision risk for birds that are susceptible due to their behavior.
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 15
3.4.1.1. Native Bird Species Collision Risk Temperatures were 30-84° F during the spring migration surveys, 38-53° F during the breeding bird survey, and 28-78° F during the fall migration surveys. The coldest temperatures were in late October and early November surveys. Sky conditions varied from clear to 100% cloud cover, and wind speeds varied from calm to over 12 mph. In general the data did not have a normal distribution in habitats. Consequently, statistical tests were used that handled non-normal data distributions, as described in the methods section above. In all seasons, Wetlands in riparian corridors had higher mean abundance and richness of native bird species than in Grasslands or Upland shrub-scrub habitat (Table 7). The difference in abundance and species richness was significantly different between the Wetland and either the Grassland or Upland shrub-scrub points. The higher richness and abundance of birds in Wetland habitats is due to a more complex habitat structure than Grassland or Upland shrub-scrub and to the presence of water in an arid environment. The Wetland habitat supports a group of species largely absent elsewhere at the site, particularly flocking ducks and shorebirds. In combination with grassland species entering the riparian zone survey points, this elevated the species richness of wetlands. The most common species across all survey periods, with over 40 individuals seen, were Horned Lark, Mallard, McCown’s Longspur, Blue-winged Teal, Green-winged Teal, Northern Shoveler, Gadwall, Western Meadowlark, Violet-green Swallow, and Vesper Sparrow (Appendix 2). These species comprised the majority (70%) of the individuals observed in surveys across the site. At the nearby Foote Creek Rim (FCR) facility overall mortality was estimated to be 1.5 BTY (birds/turbine/year) (Young et al. 2003a). This is slightly below studies in Pacific Northwest and Upper Midwest where a mortality rate of 1.98 and 2.22 BTY were measured (CIEWEP 2007). The FCR facility is situated in Grassland and Upland shrub-scrub habitat similar to that found at the site although the terrain at FCR is hillier with less large open flat areas as compared to Boswell. The bird communities at the two sites are similar in general species composition. However bird diversity and richness at Boswell were higher than at FCR in the spring migration and breeding season. There were 6.51 birds/survey at FCR versus 12.7 birds/survey at Boswell, and 2.96 species/survey at FCR versus 4.7 species/survey at Boswell (Johnson et al. 2000b). Wetlands are limited in the FCR study area. Removing the wetland points from the Boswell data results in a mean abundance of 9.5 birds/survey and a mean richness of 3.7 species/survey, still higher than the FCR data. The most common species at FCR were Horned Lark, Vesper Sparrow, Brewer’s Sparrow, Cliff Swallow, Brewer’s Blackbird, Green-tailed Towhee, Pine Siskin, American Robin, American Goldfinch and Chipping Sparrow. The most common species at the Boswell Grassland and Upland shrub-scrub points were McCown’s Longspur, Horned Lark, Vesper Sparrow, Western Meadowlark, American Avocet, Brewer’s Sparrow, Lark Bunting, Killdeer, Brewer’s Blackbird and American Crow. McCown’s Longspur, American Avocet and American Crow were not present at the FCR facility. In summary, bird density and richness is 30-50% higher (excluding wetlands) at Boswell than at FCR, and some species were only found at Boswell, most notably McCown’s Longspur, which was common. However, the two sites are similar and near enough to each other so that expected mortality rates Boswell may be like those at FCR. As has been found at other wind farms (CIEWEP 2007), passerine birds comprise the majority of mortality at FCR. Overall mortality from both turbines and meteorological towers at FCR consisted of 92% passerine birds. About half of the carcasses found (64 of 122) were considered migrants based on the dates of observation. The most common mortality occurred in Horned Lark, with 28 individuals found. Mortality at Boswell is predicted to be similar to that at FCR with mortality highest in species such as Horned Lark that are the most common and historically experience higher than average mortality at wind farms due to their flight behavior.
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 16
Table 7. Native, sensitive, and long-distance migrant mean abundance and mean richness by habitat on-site during spring and fall passerine migration and breeding bird surveys1. Long-distance Native Species Sensitive Species Migrant Species On Site On Site On Site Mean Mean Mean Mean Mean Habitat (N) Abund. Mean Rich. Abund. Rich. Abund. Rich. Wetland (5) 41.88a 5.80c 13.80 2.04e 4.56g 1.32j Upland shrub-scrub (6) 5.17b 2.40d 1.73 1.07f 0.60h 0.27k k Grassland (14) 7.04b 2.10d 2.17 0.84f 1.50h 0.40 1Numbers in the same column with similar letters are statistically the same, and numbers with different letters are statistically different.
Surveys were completed in Grasslands during the fall migratory period simultaneously at the site and reference area. A comparison of these data at the site and reference area showed no statistically significant differences in mean abundance or richness for native and sensitive species or for long- distance migrants (Table 8). Consequently, use of the reference area as a control in the BACI approach will be valid. However, a second season of observations will be made to confirm this preliminary finding.
Table 8. Native, sensitive, and long-distance migrant mean abundance and mean richness on-site and in reference area during fall passerine migration surveys. Long-distance Migrant Native Species Sensitive Species Species Mean Mean Mean Location (N) Abund. Mean Rich. Abund. Mean Rich. Abund. Mean Rich. On Site (20) 16.33 3.00 1.67 1.33 1.33 0.33 Reference (25) 29.33 2.33 1.33 1.33 1.33 0.67
The investigation of the effect of the Wheatland Reservoir on the bird community during the fall migration revealed nothing unusual. There was no significant difference in the richness or abundance of birds between points at 0.25-0.75 miles from the Wheatland Reservoir and in similar habitat farther away. This suggests that the extensive water area at the Wheatland Reservoir does not significantly change the richness and abundance of the bird community in its vicinity. Rather certain species, such as waterfowl and shorebirds, may use the shoreline and open water of the reservoir, but not venture far beyond the reservoir’s edges. This finding will be validated with incidental observations being made periodically at the reservoir in the growing season of 2010, and reported in an addendum to this report.
3.4.1.2. Sensitive and Long-distance Migrant Bird Species Collision Risk Wetlands had a greater mean abundance and mean richness of sensitive bird species and long- distance migrants than Grassland and Upland shrub-scrub (Table 7). These differences were significant for all measures except for abundance of sensitive species. Grassland and Upland shrub- scrub did not differ significantly in richness or abundance for either sensitive species or long-distance migrants. There were three to eight times as many individuals of sensitive birds and long-distance migrants in Wetlands than in Grasslands or Upland shrub-scrub. Wetland sensitive species (14) included (Appendix 2): Mallard, Blue-winged Teal, Northern Shoveler, Black Tern, American Avocet, Ferruginous Hawk, McCown’s Longspur, Vesper Sparrow, Golden Eagle, Brewer’s Sparrow, Northern Harrier, Barn Swallow, Redhead and Bald Eagle. Grassland contained twelve sensitive species: McCown’s Longspur, Vesper Sparrow, Golden Eagle, American
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 17
Avocet, Northern Harrier, Ferruginous Hawk, Sage Sparrow, Brewer’s Sparrow, Lark Bunting, Barn Swallow, Bald Eagle and Say’s Phoebe. Upland shrub-scrub contained eleven sensitive species: McCown’s Longspur, Vesper Sparrow, Brewer’s Sparrow, Golden Eagle, Northern Harrier, Say’s Phoebe, Ferruginous Hawk, Sage Sparrow, Barn Swallow, Lark Bunting and Burrowing Owl. Long-distance migrant species were not particularly common at the site, and were most common at Wetland points. Nine species occurred in Wetland habitats (Black Tern, Wilson’s Phalarope, American Avocet, Horned Grebe, Willet, Cliff Swallow, McCown’s Longspur, Barn Swallow and California Gull), four in Grassland habitat (McCown’s Longpur, American Avocet, Barn Swallow, and Rough-legged Hawk), and three in Upland shrub-scrub habitat (McCown’s Longspur, Barn Swallow and California Gull). Collision risk to sensitive species may be greater in Wetlands than in Grasslands or Upland shrub- scrub due to the greater abundance of sensitive species in those habitats. Many of the sensitive species in the Wetlands were ducks and shorebirds that were confined to these habitats, and frequently present in large flocks. Other species such as Ferruginous Hawk, Brewer’s Sparrow, McCown’s Longspur, Vesper Sparrow, Northern Harrier, Barn Swallow and Golden Eagle were present across all habitats. AES researchers also observed that species associated with Wetlands usually did not occur much beyond the edge of those habitats. Thus the risk of collision in Wetlands may be affected by how close turbines are placed to Wetlands. Whether waterfowl move between the Wheatland Reservoir and the site’s wetlands is not known; observational data are being recording in the growing season of 2010 and will be reported in an addendum to this report. Turbines are most likely to be placed in Grasslands and Upland shrub-scrub habitats at Boswell Springs. Collision risk to sensitive species and long-distance migrants in grassland is moderate given the moderate abundance of these species in point counts. The behavior of individual species affects the risk, however. For instance, although during a four-year-study Vesper Sparrow was not observed to fly in the rotor-swept area of turbines at Buffalo Ridge, Minnesota, Johnson et al. (2000a) reported that 2 of 55 fatalities there consisted of Vesper Sparrow. This is probably the result of display flights (Wells and Vickery 1994) that take the bird into the rotor swept area. Of sensitive species at Boswell Springs McCown’s Longspur, Lark Bunting and Vesper Sparrow have high abundance and a flight behavior that sometimes takes them into the rotor swept area while engaged in territorial displays. This may increase their risk of collision, although McCown’s Longspur display elevations occur primarily below the rotor swept area. Calculated expected mortality, based on values from Foote Creek Rim, for McCown’s Longspur is 0.44 BTY; for Lark Bunting is 0.18 BTY; for Vesper Sparrow is 0.05 BTY. A second season of surveys will validate these preliminary findings.
3.4.1.3. Raptor Collision Risk Raptors were present at the site at low abundances throughout the year (Table 9). A total of 80 individual raptors were seen in the spring and fall migration surveys and in the breeding bird survey at the site during 47.8 hours of observations, for an average of 1.67 raptors per hour of observation. Golden Eagle, Ferruginous Hawk, Northern Harrier and Turkey Vulture were the most commonly observed raptors. Additionally, five Golden Eagle and four Rough-legged Hawks were seen during the winter bird survey in the reference areas near the site. No raptors were observed on site during the winter bird surveys. The nearest fall hawk watch location to the site is Commissary Ridge near Kemmerer in southwest Wyoming (Hawk Migration Association of North America 2010a). Commissary Ridge is approximately 300 miles west of Boswell Springs. In 2009 there were 532 hours of observations from August 27-November 5 at Commissary Ridge, during which 2,840 raptors were observed (5.34 raptors/hour). On survey dates at Commissary Ridge that corresponded to survey dates at Boswell Springs, there were 206 raptors observed in 78.5 hours (2.62 raptors/hour). Dominant birds at Commissary Ridge, with over 100 individuals per species, were Red-tailed Hawk, Sharp-shinned Hawk, Cooper’s Hawk, Golden Eagle, Swainson’s Hawk and American Kestrel. Fourteen other
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species had fewer than 100 birds over the count period. By comparison, in the fall migration there were 2.0 raptors/hour at Boswell Springs, and no Red-tailed Hawk, Sharp-shinned, Cooper’s or Swainson’s Hawks. The nearest spring hawk watch location is Dinosaur Ridge, near Denver, Colorado (Hawk Migration Association of North American 2010b). Dinosaur Ridge is approximately 200 miles south of Boswell Springs. Spring 2009 surveys were conducted in April and May and 592 raptors were observed in 81.75 hours of observations (7.24 raptors/hour). Dates of observations at the hawk watch site did not correspond with dates of observations at Boswell Springs. The dominant species were Red-tailed Hawk, Cooper’s Hawk, Turkey Vulture and American Kestrel. During spring migration at Boswell Springs, 1.06 raptors/hour were observed and no Cooper’s Hawks were seen. In summary, the passage of raptors at Boswell Springs in spring was similar in composition to that at Dinosaur Ridge, but over the entire survey period was one-seventh to one-third the overall rate of passage at Dinosaur Ridge and Commissary Ridge respectively. For those days in the fall when surveys occurred at both Commissary Ridge and Boswell Springs, the raptor count was similar (2.62 versus 2.0 raptors/hour). It appears that in general Boswell Springs is not a significant concentration area during spring and fall raptor migration, but on some days in the fall the rate of raptor passage may be elevated as a broad front of raptors passes through in synchrony with the passage of weather fronts across the region. This preliminary finding will be validated in the second season of surveys.
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Table 9. Raptor abundance by survey. Spring Migration Breeding Bird Fall Migration Total Abundance Common Abundance (13.17 Abundance (4.17 Abundance (30.5 (47.84 hours Name hours observation) hours observation) hours observation) observation)
American 1 0 1 2 Kestrel
Bald Eagle 0 0 2 2
Burrowing 0 0 1 1 Owl Ferruginous 2 2 14 18 Hawk Golden 5 1 22 28 Eagle Northern 2 2 13 17 Harrier Prairie 0 0 1 1 Falcon Red-tailed 1 0 0 1 Hawk Rough- 1 0 0 1 legged Hawk Turkey 0 0 7 7 Vulture Unidentified 2 0 0 2 Raptor
Total 14 (1.06 raptors/hr) 5 (1.20 raptors/hr) 61 (2.00 raptors/hr) 80 (1.67 raptors/hr)
The aerial raptor nest survey at Boswell Springs in April, 2010 found two nests on site that are probably Red-tailed Hawk nests (Map Exhibit 4, points 38 & 43): one unoccupied nest on a ledge, possibly a Ferruginous Hawk nest (point 46), and a possible nest on a structure (point 36). In the reference area there were nests and possible nests of Golden Eagle, Ferruginous Hawk, Red- tailed Hawk and Swainson’s Hawk. The occupied Golden Eagle nest is 1.5 miles southwest of the site (point 6). There was a mature Golden Eagle perched next to the nest at the time of the aerial survey. No eggs were present in the nest. There was a second nest in a nearby aspen that was unoccupied at the time of the survey. The third eagle nest, also unoccupied at the time of the survey, is located just northwest of the site (point 7). The two occupied Ferruginous Hawk nests (points 109 & 35) are located north of the site. A female was incubating eggs at the time of the survey at point 35, and the male was nearby. There were four Ferruginous Hawk nests that showed no signs of occupancy at the time of the survey (points 25, 33, 21, 30), and one structure that may have been a Ferruginous Hawk nest at point 31. There was an occupied Red-tailed Hawk nest south of the site (point 9 – one adult on nest and one nearby) and two additional Red-tailed Hawk nests (points 17 and 15) whose occupancy could not be determined due to poor visibility. Lastly there was an occupied Swainson’s Hawk nest 7.5 miles southwest of the site. During the 6 hours of aerial survey time a total of 23 individual raptors were observed. On site there were two Ferruginous Hawks, one Northern Harrier and one Red-tailed Hawk. To the north of the site there were six sightings: one mature Golden Eagle, one juvenile Golden Eagle, one Cooper’s
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Hawk and the three Ferruginous Hawks associated with occupied nests. South of the site there were 13 raptor sightings: two Bald Eagles, two juvenile Golden Eagles, one mature Golden Eagle at the occupied nest, another mature Golden Eagle, two Northern Harriers, three Red-tailed Hawks and two Swainson’s Hawks. The highest concentration of raptors was seen along the Rock River valley southwest of the site. The other raptor sightings were scattered across the reference areas and the site. By several indications, raptor nesting activity is less at Boswell than in the reference area, probably due to available locations for nesting. This preliminary finding will be evaluated during a second season of surveys. Boswell Springs is not a likely concentration area for raptors during the fall or spring migration period, but is visited by two species of particular concern to the USFWS, Golden Eagle and Ferruginous Hawk. It is important, however, to recall that when wind farms are not located at raptor concentration areas, such as ridgelines and passes, raptor fatality rates have been documented to be much lower than for passerine birds and other groups (Johnson et al. 2000a; CIEWEP 2007). For example, only five raptor deaths were recorded in four years of monitoring at the FCR facility (0.03 BTY - 3 American Kestrels, 1 Northern Harrier, 1 Short-eared Owl) (Young et al. 2003a). No Golden Eagles or Ferruginous Hawks were killed, despite their presence at the FCR. Mortality rates should be similar at Boswell Springs due to the visibility afforded to raptors by flat terrain and distant unobstructed views.
3.4.2. Habitat Displacement Risk Bird species most at risk of habitat displacement are sensitive to the size of habitat patches or to intrusions into their habitat by human activities and infrastructure. Prior studies to detect habitat effects caused by wind turbines have focused on grassland, steppe and shrubland birds since these seem more sensitive to habitat displacement than forest or wetland birds and appear to be experiencing greater declines as a group in North America than forest birds (Leddy et al. 1999; Herkert et al. 2003; CIEWEP 2007; Mabey and Paul 2007). Certain grassland bird species appear to have lower nesting densities in the vicinity of wind turbines; e.g., Savannah Sparrow (Leddy et al. 1999; Johnson et al. 2000). While prairie grouse species are not known to be displaced by wind turbines, their avoidance of other areas disturbed by humans suggests they may respond negatively to wind farm development (Manville 2004; CIEWEP 2007). Possible mechanisms for avoidance behavior include the perception by grassland birds that turbines are vertical structures, like trees, and are to be avoided, and the visual disturbance of moving blades. Others have documented displacement of grassland birds due to traffic noise (e.g., Forman et al. 2003), but it is not known if a noise level from a wind turbine is perceived by birds to be similar to the same noise level from traffic. AES uses sensitive species as an indicator of displacement risk because it includes species that are already rare and should be protected, those that are area sensitive and at risk due to additional habitat fragmentation, and those that are known to be adversely affected by wind turbines. Habitats that contain more individuals of sensitive species may be at greater risk of habitat displacement than those with few. A few species at Boswell Springs are considered sensitive to habitat displacement. In the breeding season the potentially area-sensitive Vesper Sparrow (Dechant et al. 2000) was present in Grassland (8 of 14 points) and Upland shrub-scrub (3 of 6 points), but rare in Wetland (1 of 5 points). The area-sensitive Northern Harrier (Johnson and Igl 2001) was rare overall, present at a single Grassland and Wetland point in the breeding season. Neither Vesper Sparrow nor Northern Harrier are declining in the BBS region nor are they SGCN species. Of the SGCN species area sensitivity has not been studied for McCown’s Longspur (Dechant et al. 1999b), which is abundant at the site, but the rarer Lark Bunting may be area-sensitive (Dechant et al. 1999a). Brewer’s Sparrow is common at the site but is not known to be area sensitive and appears able to find and use small Upland shrub-
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scrub patches with sagebrush (Vasquez 2005). See section 3.6 below for a discussion of risk to these species. In summary, habitat displacement may occur in Grasslands and Upland shrub-scrub due to the response of grassland birds to tall structures, noise or human disturbance. The placement of turbines in Grassland and Upland shrub-scrub at the site may result in a shifting of territory location or a reduction in nesting density in Vesper Sparrow, which is not an SGCN species nor declining in the region. What is less clear is whether displacement will occur in McCown’s Longspur, which is abundant at the site but has not been studied for area-sensitivity. Declines in this species may largely be due to management practices, rather than habitat fragmentation (Dechant et al. 1999b). These preliminary findings will be studied in the second season of surveys.
3.4.2.1. Sage Grouse Displacement Risk No signs of Sage Grouse were observed in the 2009 grouse surveys. Historical lek locations were unoccupied at the time of the surveys. The site lies outside the designated Sage Grouse Core Areas. Since there is no evidence of Sage Grouse using the site at this time, impacts to Sage Grouse are unlikely. However, the presence in the area of Sage Grouse in the past and of good sagebrush habitat currently raises the possibility that Sage Grouse will use the area in the future. This possibility will be investigated by conducting a second year of Sage Grouse monitoring prior to the construction of the wind farm. 3.5. Bat Habitat Based Risk Analysis Of eighteen bat species in Wyoming, three possibly occur at the site and five are unlikely to occur at the site (Table 10). The range or the habitat for the other six species is absent at Boswell Springs. The dominant habitat mapped at the sites is Grassland and Upland shrub-scrub. Species most likely to be found in these habitats are Big Brown Bat, Fringed Myotis and Western Small-footed Myotis. As discussed, passive acoustic monitoring is occurring at the site and a report of findings will be produced at the end of 2010.
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Table 10. Bat habitat-based risk analysis. Habitat % Site Species Possible at Site Species Unlikely at Site Qualifying Land Factors for Cover Unlikely at Site Common Name Scientific Name Common Name Scientific Name Grassland & 97.61% Big Brown Bat Eptesicus fuscus Townsend's Big-eared Bat Corynorhinus townsendii Requires mine & Upland cave roosts Shrub/Scrub Fringed Myotis Myotis thysanodes Pallid bat Antrozous pallidus Rare statewide Western Small-footed Myotis Myotis ciliolabrum Emergent 1.29% Big Brown Bat Eptesicus fuscus Little Brown Myotis Myotis lucifugus Mostly forest-using Wetland Forested 0.55% Big Brown Bat Eptesicus fuscus Hoary Bat Lasiurus cinereus Mostly forest-using Wetland Little Brown Myotis Myotis lucifugus Mostly forest-using Silver-haired Bat Lasionycteris noctivagans Mostly forest-using Developed 0.49% Big Brown Bat Eptesicus fuscus Little Brown Myotis Myotis lucifugus Mostly forest-using Open Water 0.02% Big Brown Bat Eptesicus fuscus Hoary Bat Lasiurus cinereus Mostly forest-using Fringed Myotis Myotis thysanodes Little Brown Myotis Myotis lucifugus Mostly forest-using Western Small-footed Myotis Myotis ciliolabrum Pallid bat Antrozous pallidus Rare statewide Silver-haired Bat Lasionycteris noctivagans Mostly forest-using Bold Text indicates species known to be susceptible to collisions with wind turbines. Species Possible at Site = habitat at site, site is in range, and species is not rare Species Unlikely at Site = poor/marginal habitat, edge of range, or rare species
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3.6. Species of Greatest Conservation Need Nine bird Species of Greatest Conservation Need (SGCN) were observed on the site. While these species do not have a legal protected status, it is recommended that impacts be avoided or mitigated where possible. The SGCN species included: McCown’s Longspur (125 individuals at multiple points), Brewer’s Sparrow (16 individuals at multiple points), Ferruginous Hawk (18 individuals at multiple points), Lark Bunting (4 individuals at multiple points), Bald Eagle (2 individuals at 2 points in fall survey), Black Tern (35 individuals on 2 fall survey days at 1 point), Burrowing Owl (individual in the fall survey), Redhead (3 individuals at 1 point in spring survey) and Sage Sparrow (9 individuals at 3 points in spring survey). The McCown’s Longspur, Brewer’s Sparrow, Ferruginous Hawk and Lark Bunting were observed during the breeding season, and field observations indicate that these may potentially breed at Boswell Springs. The other species were observed in spring and fall migrations at a few sample points or in low numbers. Due to their rarity and ephemeral presence at the site, these species will not be considered further.
3.6.1. McCown’s Longspur In all surveys 125 individuals of McCown’s Longspur were recorded on site. Of these 73 (58%) were observed during the breeding season. Those observed during the breeding season included 59 individuals at twelve of fourteen Grassland points, 12 at three of six Upland shrub-scrub points, and two individuals at a Wetland point embedded in Grassland habitat. There is no clear geographic pattern to their distribution on the site. McCown’s Longspur breeds in short-grass prairie or heavily grazed mid-grass prairie and prefers grasslands with sparse litter cover. Sometimes it breeds in cultivated lands. It is unknown whether McCown’s Longpur is area sensitive as no studies have investigated the relationship between patch size and nest success (Dechant et al 1999b). McCown’s Longspur populations are increasing in the region, but decreasing survey-wide when data from the United States and Canada data are combined (Sauer et al. 2008). McCown’s Longspur is not present at the FCR facility (Johnson et al. 2000b) and published mortality data are not available for this species. Collision risk for the species is likely to be relatively low as typical flight heights are well below the RSA, including its well-known aerial flight display which typically reaches 10m into the air (With 1994). Since no McCown’s Longspurs were present at the FCR site, Brewer’s Sparrow and Chipping Sparrow mortality and abundance were used to calculate expected mortality. At FCR there were 2 Brewer’s Sparrow and 3 Chipping Sparrow carcasses found, or 6.0% of all mortality. The expected mortality adjusted for abundance (0.554 Chipping Sparrows & Brewer’s Sparrows per survey at FCR, 2.7 McCown’s Longspurs per survey at Boswell Springs) is 0.44 BTY. A second season of surveys will validate these preliminary findings.
3.6.2. Brewer’s Sparrow Brewer’s Sparrow was found at four of the six Upland shrub-scrub locations during the breeding season (points 6, 7, 12, 13, Map Exhibit 1). It was also found at point 19, a Wetland point surrounded by Upland shrub-scrub habitat. During the spring migration four individuals were seen: three at Grassland points and one at an Upland shrub-scrub point. During the fall migration four birds were found, two at point 19 and at one each at two Upland shrub-scrub points. In summary, Brewer’s Sparrow was common in Upland shrub-scrub habitat in the breeding season, and present during spring and fall migration. Brewer’s Sparrow requires sagebrush habitat for nesting (Walker 2004). In North America, the Brewer’s Sparrow chiefly occupies low (<3ft) shrub-scrub habitat, primarily sagebrush (Short 1984;
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 24
Vasquez 2005). A typical nesting density is one nest per 0.5-2ha. In Colorado it is known to occupy sagebrush patches as small as 6ha (Vasquez 2005). While nesting was not confirmed at Boswell Springs, the presence of adult singing males suggests that breeding was attempted. The consistent presence of the species at most of the Upland shrub- scrub points indicates that it is probably present throughout the Upland shrub-scrub habitats at the site. Flight behavior of this species suggests that collision risk will be relatively low; however 2 individuals were presumed killed at turbines in the four-year monitoring study at the Foot Creek Rim facility (Young et al. 2003a). If we assume similar mortality to the FCR facility, mortality for this species would be 0.02 BTY (2.4% of the overall 1.5BTY mortality estimate; 0.448 Brewer’s Sparrows per survey at FCR and 0.25 Brewer’s Sparrows per survey at Boswell Springs). Displacement is not likely to occur as area sensitivity has not been demonstrated in this species (Vasquez 2005). A second season of surveys will validate these preliminary findings.
3.6.3. Ferruginous Hawk Ferruginous Hawk used the site in all seasons. In the breeding season, two Ferruginous Hawks were found at two points (10 and 14, Map Exhibit 1) in the north near the off-site occupied nests. In migration, 14 individuals were seen at six points in the fall (points 2, 3, 4, 5, 6, 15) and two at two points in the spring (15, 12). Two individuals were spotted during the aerial nest survey. In the reference area, 9 individuals were sighted in the fall migration at six points, and three individuals were sighted during the aerial nest survey, all near the occupied nests north of the site. Except for the tendency of the hawks to concentrate in the north of the site and in the reference area to the north, there is no clear geographic pattern to the other hawk sightings. Threats to Ferruginous Hawks include habitat loss, accidental poisoning, and human disturbance. It is particularly sensitive to disturbance during the nesting season with remote nests typically having greater nesting success (NatureServe 2009). They utilize open habitat including grasslands, shrub/scrub and desert areas. Common nesting locations include tall trees and willows along riparian corridors or on steep slopes, ledges, and river-cut banks. The hawk was observed at low density across the site in all seasons, though it appears concentrated in the breeding season toward the north of the site, perhaps in relationship to occupied nests located north of the site in the reference area. Wind turbines at the site are not likely to result in a high level of mortality, given low raptor mortality rates at FCR and other wind farm sites. No Ferruginous Hawks were reported in the FCR mortality data (Young et al. 2003a). Disturbance of nesting pairs may result from construction in the north part of the site during the critical nesting period. Habituation to wind turbines is known to occur in raptors, as the high raptor use of the Altamont facility has demonstrated. A second season of surveys will validate these preliminary findings.
3.6.4. Lark Bunting Lark Bunting was found at two points during the breeding bird survey (points 1 and 13, Map Exhibit 1). Three individuals were found at a Grassland point (1) and one at an Upland shrub-scrub point (13). Nesting was not confirmed for this species, but its presence in breeding habitat during the breeding season suggests that breeding was attempted on site. The species was not observed on site during migration. Lark Buntings breed in the short-grass prairie region of North America, and typically prefer short grass areas often with a bare soil and shrub component. They may be area sensitive as they are not typically found in small isolated grassland patches, but no studies have directly examined the relationship between patch size and nesting success (Dechant et al 1999a). They are declining in the region and nationally (Sauer et al 2008). One Lark Bunting was killed in four years of observation at the FCR facility (Young et al. 2003a). The mortality rate for Lark Bunting is not known from other post-construction studies. If we
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 25
assume similar mortality to the FCR facility we would expect a mortality of 0.18 BTY (1.2% of the overall 1.5 BTY mortality estimate; 0.01 Lark Buntings per survey at FCR and 0.1 Lark Bunting per survey at Boswell Springs). Despite an aerial display that causes this bird to climb to a height of 10m (Shane 2000), its flight behavior is much like other sparrow-like birds, with associated low mortality rates. The low density of this species at Boswell Springs and its generally non-risky flight behavior suggest that collision mortality will likely be low, although its displacement response to turbines is unknown. A second season of surveys will validate these preliminary findings.
3.6.5. White-tailed Prairie Dogs White-tailed Prairie Dogs (Cynomys leucurus) were located in Grasslands throughout the site. Inspection of the aerial imagery for sign of prairie dog presence resulted in a map of population density (Map Exhibit 5). Prairie Dogs were densest in Grassland areas and least dense in Upland shrub-scrub habitats and along riparian corridors.
Field verification of the remote-sensed map showed the map to be generally accurate. Transects in areas mapped with high density prairie dog burrows had a mean count of 17.4 burrows per transect. Those mapped as medium density had a mean count of 8 burrows per transect, and those mapped as low-to-none had a mean count of 3.5 burrows per transect. The difference was significant between high density areas and both medium and low-to-none areas. The difference was insignificant between medium density areas and low-to-none areas.
High density prairie dog areas will experience the greatest impact from wind turbine construction, and low-to-none areas the least. Prairie dogs likely will habituate to the presence of wind turbines, but a small percentage of available habitats may be lost to turbine pads and roads.
3.6.6. Amphibians and Reptiles Twenty species of amphibians and reptiles were identified as likely to occur in the general area of the site. American Bullfrog, Boreal Toad, Northern Leopard Frog, Woodhouse’s Toad, Wyoming Toad, Eastern Yellow-bellied Racer, Plains Hog-nosed Snake, Red-lipped Plateau Lizard, Northern Sagebrush Lizard, Western Painted Turtle and Western Spiny Softshell were considered out of range or lacking habitat at the site. Many of these required elevations below 6,000 feet, well below the 7,310-8,524ft elevation of the site. The remaining species were rated as “breeding possible” or “breeding likely” and assigned to habitats on the site (Table 11). Only one species, the Boreal Chorus Frog, was confirmed to be present on the site. Incidental observations of reptiles and amphibians are being made in spring and summer 2010 and will be reported in an addendum to this report. Amphibian and reptile species that use the Upland shrub-scrub and Grassland habitats are most likely to be impacted by the wind farm development because these habitats may contain most of the turbines and associated development. Although no individuals have been observed on site, breeding in these habitats is possible for Bullsnake, Greater Short-horned Lizard and Prairie Rattlesnake.
3.6.7. Swift Fox A Swift Fox (Vulpes velox) was observed on the site on August 29, 2009 during the fall passerine survey at point 11 in the north central portion of the site. The Swift Fox has been declining due to loss of habitat, habitat fragmentation, habitat degradation caused by control of prairie dog populaitons, collision with vehicles, competition from red fox and coyote and possibly other unknown factors, and is a SGCN species in Wyoming. Increased vehicular use of the site could increase the collision risk. Other impacts to mid-sized mammals from wind development have not been documented, and overall risk is expected to be low.
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Table 11. Amphibian and reptile habitat-based risk analysis. % Site Breeding Possible Breeding Unlikely Qualifying Factors for Breeding Land Unlikely Habitat Cover Common Name Scientific Name Common Name Scientific Name Grassland Pituophis Intermountain and Upland 97.61% Bullsnake Thamnophis elegans vagrans Water very limited on site catenifer sayi Wandering Gartersnake Shrub/Scrub Uncommon, specimens outside of Ornate Box Turtle Terrapene ornata ornata Goshen county probably released Greater Short- Phrynosoma Lampropeltis triangulum Pale Milksnake Typically below 6000 feet horned Lizard hernandesi multistriata Cnemidophorus sexlineatus Uncommon, prefers sandy loose Prairie Racerunner viridis soil Crotalus viridis Ambystoma tigrinum Prairie Rattlesnake viridis Tiger Salamander Water very limited on site Emergent Boreal Chorus Pseudacris Intermountain 1.29% Thamnophis elegans vagrans Water very limited on site Wetland Frog* maculata Wandering Gartersnake Pituophis Cnemidophorus sexlineatus Uncommon, prefers sandy loose Bullsnake Prairie Racerunner catenifer sayi viridis soil Tiger Salamander Ambystoma tigrinum Water very limited on site Forested Boreal Chorus Pseudacris Intermountain 0.55% Thamnophis elegans vagrans Water very limited on site Wetland Frog* maculata Wandering Gartersnake Tiger Salamander Ambystoma tigrinum Water very limited on site Pituophis Intermountain Developed 0.49% Bullsnake Thamnophis elegans vagrans Water very limited on site catenifer sayi Wandering Gartersnake Tiger Salamander Ambystoma tigrinum Water very limited on site Boreal Chorus Pseudacris Intermountain Open Water 0.02% Thamnophis elegans vagrans Water very limited on site Frog* maculata Wandering Gartersnake Pituophis Cnemidophorus sexlineatus Uncommon, prefers sandy loose Bullsnake Prairie Racerunner catenifer sayi viridis soil Tiger Salamander Ambystoma tigrinum Water very limited on site Species Possible at Site = habitat at site, site is in range, and species is not rare Species Unlikely at Site = poor/marginal habitat, edge of range, or rare species * Species confirmed on site
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 27
4. Summary of Effects and Recommendations to Reduce Impacts Best management practices are recommended by the Wyoming Game and Fish Department (2010), U.S. Fish and Wildlife Service Wind Turbine Guidelines Advisory Committee (2010b) and the U.S. Fish and Wildlife Service Ecological Services (2010a) (Appendix 4, 5, 6). In addition to these recommendations, site-specific recommendations derived from the 2009-2010 surveys are provided below. A second season of surveys will be completed prior to construction of the wind farm and these recommendations may be consequently revised. 4.1. Endangered and Threatened Species There are no rare features that require special consideration at the site. However, the Mountain Plover has just been proposed for listing as a federally threatened species. Historic records exist for Mountain Plover on the site along Fetterman Road, and Mountain Plover habitat is present at the site. No Mountain Plovers have been observed at the site during any surveys conducted to date. Mountain Plovers are not always observed using point counts and casual observations even during the May 1-June 15 optimal survey period, and therefore may be present on the site despite current lack of evidence. • Coordinate need for Mountain Plover surveys with USFWS and WGFD and carry out, if warranted. 4.2. Bald and Golden Eagles A few Bald Eagles were observed on the site in migration. No evidence was found that Bald Eagles nested on or near the site. An occupied Golden Eagle nest and a second unoccupied nest were located one and one-half miles southwest of the site, and an unoccupied nest was just northeast of the site. Golden Eagles were observed at the site in the spring, breeding and fall surveys and in the reference area during the winter surveys. • Discuss the occurrence and management of Golden Eagle with USFWS and WGFD. • Avoid disturbing nests during the critical nesting period by following the eagle management guidelines during construction. 4.3. Native and Sensitive Bird Species Collision risk and the risk of displacement from habitat would affect sensitive bird species more than other native bird species because such species already are experiencing problems that make them a focus of conservation. For this reason, sensitive bird species are of the greatest interest in risk assessment. Of the 53 native bird species documented in point count surveys in the West Arc area, 23 are classified as sensitive. This number is higher than expected due to bird species which are declining in the region but are common elsewhere (e.g., Mallard, Barn Swallow, Blue Jay).
4.3.1. Native, Sensitive and Long-distance Migrant Bird Species Collision Risk Analysis of point count data identified significant differences in the number of native and sensitive species by habitat. Grassland and Upland shrub-scrub habitat had fewer native, sensitive and long- distance migrant species than did Wetlands. Since collision risk is related to local abundance, with behavior an important additional factor, Grassland and Upland shrub-scrub habitat pose a lower risk to native and sensitive bird species compared to wetland habitats at the site. Raptors were present in low numbers at the site throughout the year. There is no significant raptor concentration at the site during the spring or fall migration period. Due to the low abundance of raptors at the site their collision risk is expected to be low.
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 28
• Avoid placing turbines in wetland habitats (Map Exhibit 6). • Place turbines 100m from riparian corridors and wetlands larger than 5 acres. • Place turbines 1600m from active raptor nests; no active nests were detected on-site or within 1600m of the site boundary in the first survey season. • Conduct post-construction mortality survey and document number of fatalities of grassland and shrub-scrub bird species. Mortality is predicted to be highest in species that are commonest and historically experience higher than average mortality at wind farms (e.g., Horned Lark).
4.3.2 Habitat Displacement Risk Some grassland bird species (e.g., Savannah Sparrow) appear to avoid wind turbines, reducing their nesting density and affecting the local population. Vesper Sparrows and Northern Harriers are also considered area sensitive and may be impacted by wind development. Lark Bunting and McCown’s Longspur may also be area sensitive. Vesper Sparrows and McCown’s Longspurs were found at many Grassland and Upland shrub-scrub locations. Neither of these species is declining in the BBS region, but McCown’s Longspur is listed as an SGCN species. • Conduct post-construction point count surveys to document density of Vesper Sparrow and McCown’s Longspur in grassland and shrub-scrub habitats, using the BACI approach. 4.4. Bats and Collision Risk The three bat species most likely to be found in the Grassland and Upland shrub-scrub habitat where the turbines will primarily be placed are Big Brown Bat, Fringed Myotis and Western Small-footed Myotis. None of these species are known to be particularly sensitive to wind development based on mortality data from existing wind farms. Additional information on bat species composition and relative abundance will be available as an addendum to this report when the first season of bat acoustic monitoring is completed in October 2010. There is, however, a generally poor understanding of the relationship between monitored bat abundance and bat mortality. • Conduct a one year post-construction mortality study for bats. • Monitor development of bat mortality mitigation strategies and implement if feasible. 4.5. Species of Greatest Conservation Need Nine SGCN bird species were observed at the site. Of these McCown’s Longspur, Brewer’s Sparrow, Ferruginous Hawk and Lark Bunting are likely to breed at the site. McCown’s Longspur is common throughout the site with 125 individuals sighted during all surveys. Amphibian and reptile species that are most likely to use the Grassland and Upland shrub-scrub habitats are Bullsnake, Greater Short-horned Lizard, and Prairie Rattlesnake. None of these species has been observed on the site to date. Boreal Chorus Frogs have been observed on site. White-tailed Prairie Dogs are present on site with greatest concentrations in Grassland habitats. • Discuss McCown’s Longspur, Brewer’s Sparrow, Ferruginous Hawk, Lark Bunting and White-tailed Prairie Dog with WGFD.
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 29
5. Literature Cited Bat Conservation International. 2009. Species and profiles. http://www.batcon.org/index.php/education/article-and-information/species-profiles.html (Accessed 2009). Cerovski, A.O., M. Grenier, B. Oakleaf, L. Van Fleet, and S. Patla. 2004. Atlas of Birds, Mammals, Amphibians, and Reptiles in Wyoming. Wyoming Game and Fish Department Nongame Program, Lander. Chapman, S.S., S.A. Bryce, J.M. Omernik, D.G. Despain, J. ZumBerge and M. Conrad. 2004. Ecoregions of Wyoming (color poster with map, descriptive text, summary tables, and photographs). U.S. Geological Survey (map scale 1:1,400,000), Reston, Virginia. Accessed http://www.epa.gov/wed/pages/ecoregions/wy_eco.htm#Ecoregions%20denote, 4/20/2009. CEIWEP (Committee on Environmental Impacts of Wind-Energy Projects). 2007. Environmental impacts of wind-energy projects, Chapter 3. National Research Council, National Academies Press, Washington DC. Dechant, J.A., M.L. Sondreal, D.H. Johnson, L.D. Igl, C.M. Goldade, A.L. Zimmerman and B.R. Euliss. 1999a (revised 2002). Effects of management practices on grassland birds: Lark Bunting. Northern Prairie Wildlife Research Center, Jamestown, ND. Dechant, J.A., M.L. Sondreal, D.H. Johnson, L.D. Igl, C.M. Goldade, P.A. Rabie and B.R. Euliss. 1999b (revised 2002). Effects of management practices on grassland birds: McCown’s Longspur. Northern Prairie Wildlife Research Center, Jamestown, ND. Dechant, J.A., M.F. Dinkins, D.H. Johnson, L.D. Igl, C.M. Goldade and B.R. Euliss. 2000 (revised 2002). Effects of management practices on grassland birds: Vesper Sparrow. Northern Prairie Wildlife Research Center, Jamestown, ND. de Lucas, M., G.F.E. Janss, D.P. Whitfield and M. Ferrer. 2008. Collision fatality of raptors in wind farms does not depend on raptor abundance. Journal of Applied Ecology 45:1695-1703. Erickson, W.P., G.D. Johnson, M.D. Strickland, D.P. Young, Jr., K.J. Sernka and R.E. Good. 2001. Avian collisions with wind turbines: A summary of existing studies and comparisons to other sources of avian collision mortality in the United States. National Wind Coordinating Collaborative, Washington DC. http://www.nationalwind.org/pubs/default.htm. Forman, R.T., D. Sperling, J.A. Bissonette, A. P. Clevenger, C.D. Cutshall, V.H. Dale, L. Fahrig, R. France, C.R. Goldman, K. Heanue, J.A. Jones, F.J. Swanson, T. Turrentine and T.C. Winter. 2003. Road ecology: science and solutions. Island Press, Washington DC. Hawk Migration Association of North America. 2010a. Commissary Ridge raptor migration project. Jeff Smith and Mike Neal (lead contacts). Data provided by the Hawk Migration Association of North America (www.hmana.org) through its online HawkCount database (www.hawkcount.org). Accessed June 2010. Hawk Migration Association of North America. 2010b. Dinosaur Ridge Hawk Watch Site. Jeff Tim Smart and Jeff Birek (lead contacts). Data provided by the Hawk Migration Association of North America (www.hmana.org) through its online HawkCount database (www.hawkcount.org). Accessed June 2010. Herkert, J., D.L. Reinking, D.A. Wiedenfeld, M. Winter, J.L. Zimmerman, W.E. Jensen, E.J. Finck, R.R. Koford, D.H. Wolfe, S.K. Sherrod, M.A. Jenkins, J. Faaborg, & S.K. Robinson. 2003.
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Effects of prairie fragmentation on the nest success of breeding birds in the midcontinental United States. Conservation Biology 17:587-594. Johnson, G.D, W.P. Erickson, M.D. Strickland, M.F. Shepherd and D.A. Shepherd. 2000a. Avian monitoring at the Buffalo Ridge, Minnesota Wind Resource Area: Results of a 4-year study. Western EcoSystems Technology, Inc., Cheyenne WY. Johnson, G.D. D.P. Young, W.P. Erickson, C.E. derby, M.D. Strickland, R.E. Good and J.W. Kern. 2000b. Final Report. Wildlife monitoring studies for the Seawest Windpower Project carbon County, Wyoming 1995-1999. Western EcoSystems Technology, Inc. Johnson, D.H., and L.D. Igl. 2001. Area requirements of grassland birds: a regional perspective. Auk 118(1):24-34. Jamestown, ND: Northern Prairie Wildlife Research Center Online. http://www.npwrc.usgs.gov/resource/birds/gbarea/index.htm (Accessed 2010). Leddy, K.L., K.F. Higgins and D.E. Naugle. 1999. Effects of wind turbines on upland nesting birds in Conservation Reserve Program grasslands. Wilson Bulletin 111:100-104. Mabey, S and E. Paul. 2007. Critical literature review: impact of wind energy and related human activities on grassland and shrub –steppe birds. Report to the National Wind Coordinating Collaborative by the Ornithological Council, Chevy Chase MD. NatureServe. 2010. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.0. NatureServe, Arlington, VA. http://www.natureserve.org/explorer (Accessed 2010). Sauer, J.R., J.E. Hines and J. Fallon. 2008. The North American breeding bird survey, results and analysis 1966 – 2007, Version 5.15.2008. USGS Wildlife Research Center, Laurel, MD. Shane, Thomas G. 2000. Lark Bunting (Calamospiza melanocorys), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/542 Short, H.L. 1984. Habitat suitability index models: Brewer's sparrow. U.S. Fish Wildlife Service Report FWS/OBS-82/10.83, Fort Collins CO. Smallwood K.S. and C. Thelander. 2008. Bird mortality in the Altamont Pass Wind Resource Area, California. Journal of Wildlife Management 72:215-223. Smallwood, K.S., L. Rugge and M.L. Morrison. 2009. Influence of behavior on bird mortality in wind energy developments. The Journal of Wildlife Management 73:1082-1098. USFWS (US Fish and Wildlife Service). 2002. Mountain Plover survey guidelines—Montana. USFWS Ecological Services, Billings MT. USFWS – Wind Turbine Guidelines Advisory Committee. 2003. Interim guidelines to avoid and minimize wildlife impacts from wind turbines. USFWS – Division of Migratory Bird Management. 2008a. Birds of conservation concern. Published at: http://library.fws.gov/Bird_Publications/BCC2008.pdf (Accessed 2009). USFWS – Wind Turbine Guidelines Advisory Committee – Legal Subcommittee. 2008b. Legal White Paper. Published at http://www.fws.gov/habitatconservation/windpower/Subcommittee/Legal/Reports/Wind _Turbine_Advisory_Committee_Legal_Subcommittee_White_Paper_(Final_As_Posted).pdf (Accessed 2009). USFWS. 2009. Eagle permits; take necessary to protect interests in particular localities; final rules. Federal Register. 50CRF Parts 13 and 22. USFWS - Ecological Services. 2010a. Wind energy development: best management practices for migratory birds. USFWS, Wyoming Ecological Services Field Office, Cheyenne WY.
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USFWS – Wind Turbine Guidelines Advisory Committee. 2010b. Preamble and Policy Recommendations. Published at http://www.fws.gov/habitatconservation/windpower/wind_turbine_advisory_committee.h tml (Accessed 2010). USFWS. 2010c. Endangered and threatened wildlife and plants; listing the mountain plover as threatened. Federal Register 75:124. USGS (U.S. Geological Survey). 2007. nlcd_wy_utm13.tif derived from the National Land Cover Database (NLCD 2001) (United States Geological Survey, 30-Meter Grid). USDA NRCS - National Cartography & Geospatial Center, Washington DC. Vasquez, M. 2005. Brewer’s Sparrow (Spizella breweri) species assessment. Unpublished report, US Forest Service (Grand Mesa, Uncompahgre, Gunnison National Forests), Gunnison CO. Walker, B. 2004. Effects of management practices on grassland birds: Brewer’s Sparrow. Northern Prairie Wildlife Research Center, Jamestown ND. http://www.npwrc.usgs.gov/resource/literatr/grasbird/brsp/brsp.htm (Accessed 2010). Wells, J.V. and P.D. Vickery. 1994. Extended flight songs of Vesper Sparrows. The Wilson Bulletin. 106:696-702. WGFD (Wyoming Game and Fish Department). 2005. A comprehensive wildlife conservation strategy for Wyoming. http://gf.state.wy.us/wildlife/compconvstrategy/# (Accessed 2009). WGFD (Wyoming Game and Fish Department). 2009. Laramie Region: Aquatic and Combined Crucial Priority Areas. Unpublished map. WGFD, GIS Unit, Cheyenne WY. http://gf.state.wy.us/habitat/portal/index.asp. WGFD (Wyoming Game and Fish Department). 2010. Wildlife protection recommendations for wind energy development in Wyoming. March 2010 (3/19/10) Draft. Cheyenne WY. With, K.A. 1994. McCown's Longspur (Calcarius mccownii), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/096 Wyoming Natural Diversity Database (WYNDD). 2009. Data compilation for H. Kieweg, completed February 20, 2009. Unpublished report. Wyoming Natural Diversity Database, University of Wyoming, Laramie WY. Young, D.P., W.P. Erickson, R.E. Good, M.D. Strickland and G.D. Johnson. 2003a. Final report: avian and bat mortality associated with the initial phase of the Foote Creek Rim Windpower Project, Carbon County, Wyoming November 1998-June 2002. Western EcoSystems Technology, Inc. http://www.west-inc.com/reports/fcr_final_mortality.pdf (Accessed July 2010). Young, D.P., W.P. Erickson, M.D. Strickland, R.E. Good and K.J. Sernka. 2003b. Comparison of avian responses to UV-light-reflective paint on wind turbines. Western EcoSystems Technology, Inc. http://www.west-inc.com/reports/fcr_nrel.pdf (Accessed July 2010).
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Map Exhibit 1. Site Location & Survey Points
Map Exhibit 2. Site Habitats
Map Exhibit 3. Winter Bird Locations
Map Exhibit 4. Raptor Nest Locations
Map Exhibit 5. Interpreted Prairie Dog Population Density
Map Exhibit 6. Sensitive Areas
Addendum to Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm ALBANY COUNTY, WYOMING
Submitted to: Mr. Paul Martin Intermountain Wind PO Box 353 Boulder, CO 80306
Prepared by: Heather Kieweg, Maegan Droessler, Doug Mensing and Kim Chapman Applied Ecological Services, Inc. 21938 Mushtown Road, Prior Lake, Minnesota 55372 Phone: (952) 447-1919, Fax: (952) 447-1920 Email: [email protected]
January 14, 2011
AES # 08-0853 AES # 08-0853
TABLE OF CONTENTS
Executive Summary ...... iii 1. Introduction ...... 1 1.1. Project Description ...... 1 2. Study Approach and Methods ...... 1 2.1. Bat Acoustic Monitoring ...... 1 2.2. Raptor Nest Monitoring ...... 3 2.3. Incidental Amphibian Observations ...... 3 2.4. Wheatland Reservoir Observations ...... 3 3. Results and Discussion ...... 3 3.1. Bat Acoustic Monitoring ...... 3 3.2. Raptor Nest Monitoring ...... 9 3.3. Incidental Amphibian Observations ...... 10 3.4. Wheatland Reservoir Observations ...... 11 4. Summary of Effects and Recommendations to Reduce Impacts ...... 11 4.1. Bats and Collision Risk ...... 11 4.2. Risk to Nesting Raptors ...... 12 4.3. Risk to Amphibians and Reptiles ...... 12 4.4. Risk to Birds Utilizing Wheatland Reservoir No. 3 ...... 12 5. Literature Cited ...... 13
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm i
TABLES Table 1. Bat Acoustic Monitoring Set-up and Dates ...... 2 Table 2. 2010 Bat Monitoring Location Description for 3 Meter Portable Tripod Tower ...... 2 Table 3. Bat Species Detected at Proposed Boswell Springs Wind Farm ...... 5 Table 4. Bat Activity (Calls per Night) Statistics for 3 Meter Portable Tripod Tower over Various Habitats ...... 6 Table 5. Bat Activity Statistics from Acoustic Monitoring at Proposed Boswell Springs Wind Farm . 8 Table 6. Bat Calls per Night at Wind Farms (Pre-Construction) in Pennsylvania, Wisconsin, Wyoming and Iowa ...... 8 Table 7. Monitoring Observations of Occupied Ferruginous Hawk Nest...... 9 Table 8. Amphibian Observations at Site...... 10 Table 9. Wheatland Reservoir Number 3 Observation Details ...... 11
FIGURES Figure 1. Nightly Bat Activity with Daily Mean Temperature ...... 7
MAP EXHIBITS Map Exhibit 1. Site Location & Bat Acoustic Monitoring Locations Map Exhibit 2. Raptor Nest Locations Map Exhibit 3. Amphibian and Reptile Locations
APPENDICES Appendix 1. Acoustic Bat Data Voucher Calls Appendix 2. Site Photographs
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm ii Executive Summary The proposed Boswell Springs Wind Farm and associated phases (“site”) constitutes about 34 square miles of primarily Grassland and Upland shrub-scrub habitat. Elevations range from 6,713 to 7,192 feet, in the Rolling Sagebrush Steppe of the Wyoming Basin. Wetlands primarily follow riparian corridors throughout the site and a few reservoirs of open water occur along Seven-Mile Creek and Spring Creek. The topography is generally flat except for along the watercourses where it descends 60 to 80 feet. Preliminary plans are for 80-100m high turbines with 77-90m diameter blades. Bat activity at the site was typical of that found at other wind farms. Bat activity was extremely dependent upon habitat with bat activity at water containing habitats such as wetlands and reservoirs consistently present, and bat activity in grassland and sagebrush habitats extremely low or absent. Myotis species were the most commonly recorded species of the four bat species recorded on site. Myotis species have suffered from low levels of mortality at most wind sites. Two migratory forest bats, Hoary Bat and Eastern Red Bat were recorded on site. These bats are susceptible to mortality during the fall migration, and it should be expected that they would experience mortality at the site. However, there is no reason to expect that mortality would be greater at the site than at other wind farms in the region. Two confirmed unoccupied nests and two possible nests were identified on site during the aerial survey. Only one of these nests, a Ferruginous Hawk nest, was occupied during the 2010 breeding season. This nest is located in the northeastern corner of the site, and most observed flight activity was within a mile of the nest. Boreal Chorus Frogs were observed on seven different occasions on site, and Tiger Salamanders were observed on two different occasions. Both species are likely present throughout the site in wetlands and small pools within the riparian areas. No other species of reptiles or amphibians were observed. Observations at Wheatland Reservoir Number 3 showed that while there was considerable waterfowl use of the reservoir there were no clear flight paths between the reservoir and the site. Waterfowl remained on or above the reservoir. Given these findings, specific recommendations focus on avoiding known sensitive areas, and do not differ from those given previously in the Year 1 final report (Kieweg et al. 2010). Sensitive areas include wetlands along the riparian corridors and wetlands over 5 acres in size. Management concerns for the Ferruginous Hawk should be discussed with the USFWS and WGFD, and the occupied Ferruginous Hawk nest should be buffered. A second year of surveys will be completed prior to construction to validate these recommendations
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm iii
1. Introduction Intermountain Wind retained Applied Ecological Services, Inc. (AES) to provide biological surveys for a potential wind farm in central Albany County, Wyoming (Map Exhibit 1). AES conducted a season of biological surveys at the site from spring 2009 through fall 2010. Results of surveys completed through spring 2010 were reported in a final report of the first year of survey work Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm (Kieweg et al. 2010). This report addendum summarizes methods and results of field work conducted during the summer and fall of 2010 including: bat acoustic monitoring, incidental amphibian and reptile observations, monitoring of raptor nests and additional observations of the bird community at the Wheatland Reservoir. Implications of these surveys for the development of the wind farm project are discussed and recommendations for avoiding and minimizing biological impacts are provided. A second season of surveys will be completed prior to construction of the wind farm. 1.1. Project Description The proposed Boswell Springs Wind Farm (the “site”) is an approximately 34 sq mi area located 40 miles northwest of Laramie, Wyoming (Map Exhibit 1). The site is located in the Rolling Sagebrush Steppe of the Wyoming Basin. The basin is a broad intermontane region dominated by grasslands and shrublands that often are big sagebrush shrublands. Precipitation averages from 6 to 16 inches per year. The topography consists of rolling plains, with hills, cuestas, mesas and terraces. The site is relatively flat, but a westward-flowing watercourse descends 60 to 80 feet through the center of the site along Seven-mile Creek and to a lesser extent Spring Creek. Elevations range from 6,713 to 7,192ft (2,046 to 2,192m). South and east of the site the terrain descends to Rock Creek, and to the northeast of the site the landscape ascends and transitions into foothills of the Laramie Mountains. Sagebrush still dominates most of the region, but invasive European annual grasses are replacing sagebrush in some areas (Chapman et al. 2004). Design specifications for the wind turbines have not been completed. The turbines are expected to be 1-2 MW, with tower heights of 80-100m and rotors of approximately 77-90m diameter. Based on these dimensions, the upper limit of the rotor swept area (RSA) would be 118m to 145m, and the lower limit of the RSA would be from 35m to 62m. 2. Study Approach and Methods 2.1. Bat Acoustic Monitoring Bat activity data were collected using broadband acoustic detectors (AnaBat SD-2 zero-crossing ultrasonic detectors, Titley Electronics Pty Ltd, Ballina, NSW Australia). These AnaBat detectors record the frequency of bat echolocation calls over time to compact flash cards (CF cards). We calibrated sensitivity of the detectors according to Larson and Hayes (2000) prior to field deployment. One detector was mounted on a portable tripod located on private land east of Medicine Bow, Wyoming (Map Exhibit 1). Seven monitoring locations were chosen for the 3m portable tripod. This method was requested by the Wyoming Game and Fish Department in order to represent the different habitats found within the site (Map Exhibit 1). A description of habitat types and deployment dates can be found on Table 2. The tripod tower was equipped with one detector, installed at 3m above ground level. The microphone for the detector was placed in a waterproof casing (Bat-hat; EME Systems, Berkeley, California, USA) with a detector plate positioned at 45 degrees to reduce lower elevation noises. The microphone was positioned to face due north, opposite the prevailing wind direction. The microphone was connected with a Teflon extension cable to the detector/recording system, which was housed at ground level in a weatherproof box.
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 1
The detector was powered by a 12V battery, recharged daily by a 10W solar panel attached to the tower at ground level. The detector was programmed to record calls from 6:00 pm to 6:00 am each day from May 25 to October 19, 2010. This report provides data collected from the one detector installed in 2010.
Table 1. Bat Acoustic Monitoring Set-up and Dates Anabat Serial Number Sensor Elevation Deployment Date Removal Date 80246 3 meters May 25, 2010 October 19, 2010
Table 2. 2010 Bat Monitoring Location Description for 3 Meter Portable Tripod Tower Site Number Start Date End Date Habitat Description
1 5/25/2010 6/16/2010 Playa pond on grassland 2 6/16/2010 7/09/2010 Small reservoir 3 7/10/2010 7/29/2010 Sagebrush 4 7/29/2010 8/18/2010 Wetland with creek 5 8/18/2010 9/08/2010 Grassland with rock outcroppings 6 9/8/2010 9/29/2010 Grassland 7 9/29/2010 10/19/2010 Reservoir and wetland area
Bat acoustic monitoring data were downloaded approximately every three weeks following deployment. Upon arrival at the monitoring location, the AnaBat unit was turned off, the CF cards removed and replaced with an empty card. The CF cards were downloaded using a computer application program, cfcread.exe, designed for downloading and processing AnaBat data. Once the data were downloaded, they were transferred for later analysis to a folder with the site name, card number and date of download. Each card was given a specific number which correlated to the monitoring location, unit number and monitoring elevation (Table 1). Once data downloads were completed, the data were transferred to an ftp site at AES’s main headquarters in Brodhead, Wisconsin for processing. We downloaded and processed data collected from the detector throughout the sampling period. All irrelevant noise was eliminated from the data prior to summary and analysis using filters in the AnaBat analysis program, AnalookW.exe. The clean bat calls were placed in previously labeled bat call files with monitoring location, CF card number and date of download. We defined a bat call as a series of ≥2 echolocation calls with duration of ≥10 ms (Hayes 1997; Thomas 1988; Weller 2007). Each call file was visually inspected to determine whether it was a bat pass. Bat passes were then identified to species, comparing minimum frequency and call shape to a library of vocal signatures (O’Farrell and Gannon 1999). Myotis were identified only to genus level due to the difficulty in differentiating between species. Unidentifiable calls were labeled as being produced by high (≥35 kHz) or low (<35 kHz) echolocating bats based on their minimum frequency. To determine relative activity at a monitoring location it is necessary to quantify the number of bat calls or call sequences per unit time. For individual species the bat activity was calculated as the number of bat call files per night. This simple count of total recorded files has been shown to over- estimate activity levels in some cases (Kalcounis et al. 1999) because multiple call sequences in a file could be made by a many individuals of a single species, resulting in an underestimate, or multiple files of call sequences could be made by one individual in a short amount of time, producing an overestimate. Miller (2001) suggested that an Activity Index be calculated by counting the number of
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 2
1-minute intervals, indicated by a recorded file, in a single night in which a particular species is active. A species is considered present during a 1-minute block of time regardless of the number of sequences within a file, or the number of files for that species in the 1-minute interval (Miller 2001). In our experience the simple metric of calls or call sequences per night by species differed only slightly from the Activity Index proposed by Miller (2001). This lack of difference may be characteristic of landscapes in the West where our studies were completed. For this reason we report only the simple calculation of calls or call sequences per night. 2.2. Raptor Nest Monitoring An aerial survey from a fixed wing aircraft flown by France Aviation was conducted on April 26, 2010. The site and a reference area were surveyed on half-minute transects at an elevation of 200 feet. To avoid disturbance, nests were not circled; even if nest status was uncertain. Locations of all raptor activity and confirmed and possible nests were recorded as GPS points. Nests were classed as confirmed nests or possible nests. Confirmed nests were clearly nests. Possible nests were structures that may have been nests but it was not possible to confirm this due to poor visibility and other factors. The confirmed nests were classed as occupied or unoccupied, and the species using the nest identified where known. Unoccupied nests were nests that did not show occupancy at the time of the survey. These nests may have been occupied at other times during the season due to late nesting attempts or could be occupied in future years. Where possible nests were field verified from the ground. Snow made passage impossible at the time of the aerial survey, therefore ground confirmations were made later in the season. Occupied nests, where access was possible, were monitored from the ground to establish information on flight paths. 2.3. Incidental Amphibian Observations Species and location were recorded for all amphibians and reptiles observed on site. Incidental observations of reptile and amphibian species were completed during all surveys from spring 2009 through fall 2010. Incidental observations were augmented with deliberate searches in summer 2010. For amphibians these searches included walking wetland perimeters, flushing amphibians from emergent vegetation, and dip-netting into open water and submergent vegetation. Deliberate searches occurred on June 16 and August 18, 2010 and consisted of over five hours of surveying. For reptiles these searches included searching rock outcrop areas. 2.4. Wheatland Reservoir Observations The Wheatland Reservoir is a large body of water southeast of the site. Records of many Species of Greatest Conservation Need (SGCN) are known from the Reservoir including: Ferruginous Hawk, Clark’s Grebe, Bald Eagle, Black-crowned Night Heron, Caspian Tern, Common Loon, Long-billed Curlew and Peregrine Falcon (WYNDD 2009). In addition there are historical records of American White Pelican, California Gull and Herring Gull breeding colonies near the reservoir. In order to characterize bird use of the reservoir and to establish whether flight paths exist between the reservoir and the site, additional observations of bird activity on the north, northwest and western banks of the reservoir were made in the summer of 2010. 3. Results and Discussion 3.1. Bat Acoustic Monitoring Impacts to bat species are of increasing concern (Arnett et al. 2008). Most wind farms have not documented large bat kills, but migratory forest bats are affected in some areas and in West Virginia an estimated 1,364 - 1,980 bats were killed in a 6-week period in 2004 (Arnett 2005). Because bats in the temperate zone give birth to one or two young each year; the biological and cumulative
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 3
significance of the reported mortality is unclear (O’Shea and Bogan 2003). Of 45 bat species in the continental U.S., six are federally endangered and 20 are at risk. Cave-hibernating bats are also declining due to White Nose Syndrome, a fungal disease that eliminates 95% of populations where it occurs in the Northeast and Midwest (Bat Conservation International 2010). The low reproductive rate, the potential for high mortality, and large proportion of at-risk species has raised concern with biologists and regulatory agencies. Few resident bats seem to be killed at wind farm facilities and most wind farms have not documented large bat kills. For farms that reported kills, Johnson (2005) identified 11 species and learned that over 90 percent were migratory forest bats (Hoary (Lasiurus cinereus), Eastern Red (Lasiurus borealis), Silver-haired (Lasionycteris noctivagans)) and Tri-colored Bat (Perimyotis subflavus, formerly Eastern Pipistrelle). The first three migratory forest bat species travel up to 1,200 miles in spring and fall and spend summers in the northern United States and Canada (Kurta 1995; Cryan 2003). The Tri- colored Bat (not expected to occur at the site) migrates shorter distances to hibernate (Bat Conservation International 2009). Half of all reported bat collisions occurred between August 16-31 and a quarter of all collisions between September 1-15, presumably corresponding with the peak of fall bat migration (Johnson 2005; Arnett et al. 2008). Most of the other collisions were July 16-August 16 and September 16- October 15. There is little mortality during the April-May spring migration for unknown reasons (Zinn and Baker 1979; Cryan 2003; Cryan 2008). Mortality is often associated with passing weather fronts and nights with low wind speed when bats appear to migrate (Arnett et al. 2008). Some biologists reported that migratory forest bats travel in flocks (Carter 1950; Thomas 1921), in daytime (Jackson 1961; Hall 1946; Mumford and Whitaker 1982), and at an altitude of up to several thousand feet (Griffin and Thomson 1982; Peurach 2003). Mortality is also associated with a bat’s preferred altitude (Allen Kurta unpublished data); and the Hoary Bat is found most often above 30m, in the rotor swept height, rather than at lower elevations (Baerwald and Barclay 2009). A consistent pattern between habitat and mortality has not been established (Arnett et al. 2008), but turbines placed in habitats with low bat activity are likely to pose less risk to bats compared to forests, rivers and lakeshores where bat activity tends to be higher (Johnson 2005; Arnett 2005). When foraging, moving and migrating, bats appear to follow edges and linear features (Hall 1962; Furlonger et al. 1987; Verboom and Huitema 1997; Murray and Kurta 2004; Arnett 2005; Cryan and Veilleux 2007; Kurta et al. 2007; also see Larkin 2006). Infrared imagery shows that bats often investigate towers, pass them multiple times, and land on stationary blades (Horn et al. 2008). Bats may avoid most direct collisions but appear susceptible to the pressure change caused by passing blades. Lung hemorrhaging (barotrauma) has been found in 90 percent of examined bat fatalities (Baerwald et al. 2008). Several hypotheses exist to explain the ultimate cause of bat mortality at wind farms. Of these, Cryan and Barclay (2009) recommend two hypotheses as priorities for experimentation: 1) turbines attract bats, and 2) bat collision is random and unrelated to species, age or sex. If high mortality is due to turbines attracting bats, design modifications or other technology could be developed to reduce risk to bats. If collisions are random, better siting of wind farms to avoid migratory pathways and areas of concentration may be appropriate. Three species (Hoary Bat, Eastern Red Bat and Silver-haired Bat) known to occur in Wyoming near the Boswell Springs site have experienced a high level of impact at other wind farms (Johnson 2005). The Hoary Bat is a tree bat and one of the largest bats in Wyoming. It ranges from Canada to South America. These bats typically inhabit forested areas and tend to avoid humans. Hoary Bats migrate long distances in groups following the same migration paths as birds. The Eastern Red Bat, a medium-sized bat, ranges from Canada to central Florida east of the Rocky Mountains. This species
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 4
also can migrate long distances. Silver-haired Bat, another tree bat found in Wyoming also migrates long distances, has a range similar to the Hoary Bat and prefers mature forested areas with water nearby. Like many bats, it roosts under bark but also in hollow trees, which are more common in mature than in young forests. Mortalities at the Foote Creek Rim facility (approximately 25 miles northwest of the site) consisted of 87% migratory forest bats, primarily Hoary Bats and a few Silver- haired Bats (Young et al. 2003). Three other species also have reported impacts at wind farms. The Big Brown Bat is large and ranges from southern Canada to northern South America. In general it inhabits cities, towns and rural areas and is uncommon in heavily forested areas. The Little Brown Bat is medium-sized and ranges from southern Alaska to Mexico. Little Brown Bats inhabit forested areas near water. The Northern Myotis (which is not thought to be on-site) is a medium-sized bat distributed sparsely across forested regions of the eastern United States from southern Canada to Florida. Northern Myotis typically roost and forage in dense forest stands. At the Foote Creek Rim facility Little Brown Bats represented 9% of total mortality and Big Brown Bat represented 1% of total mortality (Young et al. 2003). Four species of bats (Big Brown Bat, Hoary Bat, Eastern Red Bat, Pallid Bat), unidentified Myotis species and two unidentified groups of bats (high and low echolocation frequencies) were detected at the site (Table 3). There are four documented species of Myotis in Albany County, WY. These include Western Small-footed Bat, Little Brown Bat, Fringed Myotis, and Long-legged Myotis. Roosting and foraging preferences of these species with available on-site resources suggest likely use by the Western Small-footed Bat and Fringed Myotis. Unidentified high-frequency bats may include the Little Brown Bat, Eastern Red Bat, Western Small-footed Bat, Fringed Myotis, and Long-legged Myotis; low-frequency bats may include the Hoary Bat, Big Brown Bat, Silver-haired Bat, Pallid Bat, and Townsend’s Big-eared Bat. Call vouchers for these species can be found in Appendix 1.
Table 3. Bat Species Detected at Proposed Boswell Springs Wind Farm Scientific Common Roosting Detection Period Subfamily Feeding Habitat Name Name(s) Habitat During Survey Species of Greatest Conservation Need - Tier II Meadows, over Eptesicus Buildings or 5/25/2010 – Vespertilioninae Big Brown Bat water, among fuscus trees 6/30/2010 trees, backyards Among trees, Lasiurus 7/30/2010 – Vespertilioninae Eastern Red Bat clearings and over Trees borealis 8/14/2010 water Little Brown, Over water, near Western small- trees, over Buildings, Myotis 5/25/2010 – Myotinae footed, Fringed, pastures, or dead trees, species 8/27/2010 and Long-legged streets near mines, caves Myotis roosts Species of Greatest Conservation Need - Tier III Antrozous Trees, rock Vespertilionidae pallidus Pallid Bat Ground crevices, 6/27/2010 mines, caves Not listed as Species of Greatest Conservation Need Lasiurus Clearings, fields, 5/25/2010 – Vespertilioninae Hoary Bat Trees cinereus and over streams 7/3/2010
In order to sample in various habitats, and determine habitat use by the different bat species, the 3m tripod was moved every 3 weeks when data cards were exchanged (site locations and descriptions located in Table 2; site photographs are located in Appendix 2). Data results for the various habitats are listed below in Table 4.
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 5
The habitats with the most bat calls/night were the playa pond on the grassland and the small reservoir (accounting for 90 percent of all calls). Both of these habitats had significant open water that would have attracted insects and foraging bats. Bats were also found in small numbers at the wetland/creek site that also had open water and in fewer numbers (4 bats) at the grassland site with rock outcrops that did not have open water. No bats were detected at Site 3, 6, or 7. The presence of non-bat noise in the data indicated that the monitors were recording properly. Site 3 and 6 had no water present. The reservoir (Site 7) had water, but monitoring was conducted after Sept. 30 when bat activity was probably limited by cold temperatures and low insect activity. These data indicate that water is a key factor influencing bat activity at Boswell Springs, as it has been shown at other locations. Some species of insectivorous bats concentrate foraging directly over or in the vicinity of water (Bogdanowicz 1994; Brigham 1991; Jaberg et al. 1998). Water is also required for drinking by many species (Kurta et al. 1989, 1990), which is reflected in the concentration of bats observed at watering holes in arid and semiarid regions (Lumsden and Bennett 1995; Swewczak et al. 1998). Some bats also visit watering holes to obtain nutrients such as calcium and sodium, which may otherwise be limiting resources, especially during pregnancy and lactation (Barclay 1995).
Table 4. Bat Activity (Calls per Night) Statistics for 3 Meter Portable Tripod Tower over Various Habitats Calls per night Big All % of Habitat Brown Hoary Eastern Pallid Myotis Unknown Total All Site Description Bat Bat Red Bat Bat Species Species Calls Calls
1 Playa pond on 0.22 0.39 0 0 0.83 0.43 1.87 17.8 grassland 2 Small reservoir 0.53 1.0 0 0.06 6.06 2.59 10.24 72.2 3 Sagebrush 0 0 0 0 0 0 0 0 4 Wetland/creek 0 0 0.15 0 0.15 0.7 1.0 8.3 5 Grassland with 0 0 0 0 0.22 0.22 0.44 1.7 rock outcrops 6 Grassland 0 0 0 0 0 0 0 0 7 Reservoir and 0 0 0 0 0 0 0 0 wetland area
From May 25 to October 19, 2010 (149 consecutive nights) we recorded a total of 241 calls from the detector. Bat activity was highly variable over the study period (Figure 1) due to a combination of seasonal changes in bat activity and sampling in habitats with varying amounts of quality bat foraging habitat. Bat activity peaked from mid-June through mid-July when the equipment was monitoring the highest quality bat habitats with abundant water resources. During this time period the bat activity increased as the mean daily temperatures increased. Recorded calls were absent from mid- July to early August when the sampling equipment was in Sagebrush habitat with no water resources to attract foraging bats. A small bat activity peak occurred in August as migrating forest bats joined the resident bats, and as young-of-the-year bats joined older bats. The levels of bat activity during this period were likely lower than at sites with water. Bat activity was absent in September, again probably due to the poor quality of the Grassland habitat for bat foraging. Finally late in the season as the daily mean temperature dropped below 50°F and cold nights and frost reduced insect populations there were no recorded bats despite recording in a wetland/reservoir habitat. By this time bats had moved south or entered hibernacula.
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Figure 1. Nightly Bat Activity with Daily Mean Temperature
The seasonal pattern and peaks in this study shows similarities to that in several other studies. In Tennessee, bat activity exhibited a seasonal peak from August to mid-September in all three years of the study (Fiedler 2004). Similar patterns were also reported in Minnesota (Johnson et al. 2004), Pennsylvania (Arnett et al. 2006), Wisconsin (Redell 2006) and Wyoming (Gruver 2002). However, in an Iowa study bat activity peaked in July and August and declined in September; detection had mostly ceased by October (Jain 2005). The timing of high activity and the overall incidence of bat fatality has been previously reported (e.g., Fiedler 2004; Johnson et al. 2004; Jain 2005) and suggest that temporal patterns of activity may prove useful for predicting the timing of fatality events (Redell et al. 2006). We found that bat activity generally increased with increasing temperatures (Figure 1), with peaks in the bat activity corresponding directly to peaks in temperature. Acoustic monitoring studies at other wind facilities reported similar variation in bat activity with temperature (e.g., Fielder 2004; Redell et al. 2006; Reynolds 2006). Erickson and West (2002) reported that both regional patterns of climatic conditions as well as local weather conditions could predict activity of bats. Strong winds can influence insect abundance and activity, which in turn influences bat activity. Bats are known to be less active in periods of rain, low temperatures and strong winds (Eckert 1982; Erickson and West 2002). Myotis species was the most frequently recorded bat (likely the Western small-footed or Fringed Myotis) 52.7 percent of all calls) (Table 5). The Hoary Bat comprised 10.8 percent of all calls. The Big Brown Bat made up 5.8 percent of calls, the Eastern Red Bat 1.2 percent of calls, and Pallid Bat 0.4 percent of calls. The remaining calls were unidentifiable in the high frequency call group (21.6 percent of all calls) or low frequency call group (7.5 percent of calls). Acoustic data collected at the nearby Foote Creek Rim site found a similar distribution of calls with 79.2% of calls belonged to species of Myotis, while the remaining 20.8% of calls were from Big Brown, Silver-haired and Hoary Bats (Gruver 2002). The high percentage of Myotis calls at the Foote Creek Rim site is consistent with the results from Boswell Springs. Higher numbers of migratory bats, particularly Hoary Bats may have been recorded if monitoring had occurred at higher elevations or in the vicinity of water during the August migration period. No Hoary Bat calls were recorded during the August migration period.
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Table 5. Bat Activity Statistics from Acoustic Monitoring at Proposed Boswell Springs Wind Farm
Species Elev. Totals % All Calls Calls Per Night Big Brown Bat 3m 14 5.8 0.09 Hoary Bat 3m 26 10.8 0.17 Eastern Red Bat 3m 3 1.2 0.02 Pallid Bat 3m 1 0.4 0.01 Myotis 3m 127 52.7 0.85 Unknown >35 kHz 3m 52 21.6 0.35 Unknown <35 kHz 3m 18 7.5 0.12 Total Calls 241 - 1.62
The mean number of calls per night was 1.62 across the entire monitoring season, 0.3 calls per night during the July 15 – Sept. 30 migratory period, and 5.43 calls per night during the May 25 – July 3 sampling in the highest quality habitats. The overall bat activity and the migratory period activity is lower than results from studies in south-central Wisconsin in a July 19-Sept. 30 survey (Redell et al. 2006), Pennsylvania in an August 1 through November 1 survey (Arnett et al. 2006), Wyoming (June 26 – August 21, 2000 and June 11 – Aug 13, 2001 survey) (Gruver 2002), and Iowa (September 4 – October 9, 2003 and May 26 – September 24, 2004 survey) (Table 6). The early season high quality habitat activity is lower than results from all of these studies except the Pennsylvania study.
Table 6. Bat Calls per Night at Wind Farms (Pre-Construction) in Pennsylvania, Wisconsin, Wyoming and Iowa
Bat Call Type Sensor Elevation PA WI IA WY Mean
High Frequency (>25Hz) High (>40m) 1.0 2.0 NA NA 1.5 Low (<2m) 2.0 10.0 NA NA 6.0
Low Frequency (<25Hz) High (>40m) 0.4 5.0 NA NA 2.7 Low (<2m) 1.5 6.0 NA NA 4.3 High & Low Frequency High & Low NA NA 55.5 2.2 28.9 Total Calls Per Night 4.9 23.0 55.5 2.2 21.4
In summary bat acoustic monitoring revealed that bat activity patterns were generally typical of that found at other wind farms, and the site had generally lower activity levels than many other wind farms. Bat activity was highly dependent upon the presence of water in the habitat with the highest activity rates near wetlands and open water bodies. A high percentage of the activity was from Myotis, which are known to be susceptible, but not highly susceptible, to mortality. If monitoring had occurred at higher elevations a greater number of Hoary Bats, which tend to forage at high elevations, may have been recorded. Hoary Bats have suffered from significant levels of mortality at several wind farms, but this site does not appear to be on a significant migration path for Hoary Bats. Acoustic monitoring from the nearby Foote Creek Rim facility recorded slightly higher numbers of bats/night than that found at this site. At the Foote Creek Rim the estimated bat mortality (corrected for observer error and scavenger removal) was 1.34 bats/turbine/year (Young et al. 2003). There is no reason to expect that bat mortality at this site will be greater than mortality at the Foote Creek Rim. A second year of surveys will be completed prior to construction to validate these preliminary findings.
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3.2. Raptor Nest Monitoring Two confirmed nests, unoccupied at the time of the survey, and two possible nests were identified on the site during the aerial survey (Map Exhibit 2). Ground observations showed that the possible nest at point 36, a nest on a building, was unoccupied and had been covered in barbed wire. The possible nest at point 46 was not located during ground surveys. At point 43 there is a large unoccupied nest located in a conifer. It is large enough to possibly be a Golden Eagle nest. Nest number 38 was an occupied Ferruginous Hawk nest, which was also occupied in 2009. Below the occupied nest there was a second unoccupied nest. Flight activity at the occupied nest was monitored and results are reported below. The nests in the reference area to the south and southwest of the site were inaccessible by public road, therefore ground confirmation of nesting status was not possible. These nests included three occupied nests (Golden Eagle, Red-tailed Hawk, Swainson’s Hawk) and four unoccupied nests (two Ferruginous Hawk nests and two probable Red-tailed Hawk nests). Of the nests in the reference area to the north of the site one nest was inaccessible: a Ferruginous Hawk nest unoccupied at the time of the aerial survey (point 25). The possible nest at point 31 was not found. Ground confirmation on June 17, 2009 found that the remaining four nests (points 7, 33, 35 and 109) were unoccupied, although the nests were all in good condition. The Ferruginous Hawk nest located at point 38 was monitored for 5.7 hours from June 16 – July 29, 2010 (Table 7). During this time three flights to and from the nest were observed. Two of the flights were brief flights away from the nest a half-mile to the east and west. The third flight was in a wandering path to the southeast with the raptor last observed ¾ of a mile southeast of the nest. Other observations of Ferruginous Hawks during the 2009 breeding season were made at two locations, one within ½ mile of the nest and one just over 4 miles from the nest.
Table 7. Monitoring Observations of Occupied Ferruginous Hawk Nest. Date Start/End Temp Wind Cloud Comments Time Cover 6/16/2010 0930 - 1020 62 10 mph out Clear There was one brief flight west of the nest of NW ½ mile and back to the nest. The rest of the time the bird remained at the nest. 6/16/2010 1825 - 1925 62 15 mph out 50% Watched Northern Harrier but did not see of W the Ferruginous Hawk fly from nest. 7/09/2010 0900 - 1000 58 Trace out of 10 % No raptors observed. W 7/10/2010 0915-1020 61 10-15 mph 40% One Ferruginous Hawk flew from the nest out of W to the east for ½ mile and looped back to the nest. A second Ferruginous Hawk followed a wandering path from the nest to the southeast. It was probably foraging, although it flew high away from the nest, landed on a hillside and then continued away from the nest to the southeast until it was lost from visibility approximately ¾ of a mile away. It did not return to the nest during the observation period. 7/10/2010 1200 - 1215 80 10-15 mph 75% No raptors observed. out of W 7/29/2010 1230 – 1300 74 15 mph out 50% No raptors observed. of W
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In summary one occupied Ferruginous Hawk nest was discovered in the northeastern portion of the site. All other nest structures on site were unoccupied in 2010. Wind turbines at the site are not likely to result in a high level of Ferruginous Hawk mortality, given low raptor mortality rates at Foote Creek Rim (FCR) and other wind farm sites. No Ferruginous Hawks were reported in the FCR mortality data (Young et al. 2003). Disturbance of nesting pairs may result from construction in the north part of the site during the critical nesting period. Habituation to wind turbines is known to occur in raptors, as the high raptor use of the Altamont facility has demonstrated. A second season of surveys will validate these preliminary findings. 3.3. Incidental Amphibian Observations Boreal Chorus Frogs were observed seven times and Tiger Salamanders were observed twice during survey work at the site (Map Exhibit 3, Table 8). Boreal Chorus Frog observations were from vocalizations at all but one location, and Tiger Salamander observations were visually confirmed. No other amphibians or reptiles were observed during surveys on the site. Table 8. Amphibian Observations at Site. Common Name Scientific Name Date Location Notes
Boreal Chorus Frog Pseudacris maculata 5/24/2009 A9: creek/pond vocalizations only Boreal Chorus Frog Pseudacris maculata 6/16/2010 A1: playa pond vocalizations only Boreal Chorus Frog Pseudacris maculata 6/16/2010 A2: borrow ditch vocalizations only Boreal Chorus Frog Pseudacris maculata 6/16/2010 A3: reservoir vocalizations only Boreal Chorus Frog Pseudacris maculata 7/9/2010 A4: creek/pond vocalizations only Visibility poor, identity Tiger Salamander** Ambystoma tigrinum 8/18/2010 A5: creek/pond not positively confirmed Boreal Chorus Frog Pseudacris maculata 7/29/2010 A6: creek/pond vocalizations only Tiger Salamander Ambystoma tigrinum 8/18/2010 A7: stock reservoir Boreal Chorus Frog Pseudacris maculata 8/18/2010 A8: stock reservoir
Boreal Chorus Frogs were observed in wetlands and ponds along both Seven-mile Creek and Spring Creek, and were also observed in one playa pond. They are likely present throughout the site in wetlands and small pools in the riparian areas and isolated playa ponds. They may overwinter in upland areas adjacent to the wetlands, or travel a few hundred meters between wetlands through upland habitats (NatureServe 2010). The species is considered both globally secure and secure in Wyoming. Assuming proper precautions are taken to protect riparian areas risk to Boreal Chorus Frogs would most likely be limited to direct mortality from vehicular traffic. Tiger Salamanders were located along Seven-mile Creek in a stock reservoir and in another ponded area. They are likely present in small numbers throughout the site in areas of ponded water during the breeding season, and within a few hundred meters of water bodies in upland habitats where burrowing is possible during the non-breeding season. The species is considered globally secure and apparently secure in Wyoming (NatureServe 2010). Again, assuming proper precautions are taken to protect riparian areas, the risk to Tiger Salamander would most likely be limited to direct mortality from vehicular traffic. Surveys were not exhaustive and it is likely that small populations of other amphibian and reptile species are present on the site. Possible species include: Bullsnake, Intermountain Wandering Gartersnake, Prairie Rattlesnake, Pale Milksnake, Prairie Racerunner, Ornate Box Turtle and Greater Short-horned Lizard. Risks to these species could include direct mortality from vehicular traffic, harassment from staff employed to construct or maintain the turbines and limited loss of habitat due
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 10
to turbine and road construction. A second year of surveys will be completed prior to construction to validate these preliminary findings. 3.4. Wheatland Reservoir Observations A total of 5.2 hours of observations of bird behavior in and around the north and west sides of Wheatland Reservoir Number 3 were made from June 16, 2010 through August 18, 2010 (Table 9). The time of day of observation varied from early morning to late afternoon. Bird activity was concentrated on and near the reservoir. There was little activity off the water, and no observations of consistent flight paths between the Reservoir and the proposed site. Risk to birds using the Wheatland Reservoir is minimal due to their tendency to remain on or near the Reservoir.
Table 9. Wheatland Reservoir Number 3 Observation Details Date Start/End Temp Wind Cloud Comments Time Cover 6/16/2010 16:40 – 60 15 mph 60% Considerable waterfowl on reservoir but little 17:40 out of W movement off the water. 6/16/2010 19:30 – 62 10 mph 50% Waterfowl abundant but flights restricted to 20:30 out of W over reservoir. 7/09/2010 10:10 – 62 Calm 10 % Turkey Vulture and songbirds observed but no 10:40 discernable flight paths. 7/10/2010 12:20 – 80 10-15 mph 75% General songbird activity with no discernable 13:00 out of W flight path from reservoir to/from site. 7/29/2010 14:30 – 88 10-15 mph 60% No discernable flight path from reservoir to 15:45 out of W wind farm site. 8/18/2010 07:30 – 58 5 mph out Clear Observed northern harrier in area but no 08:15 of SW discernable flight pattern between reservoir and wind farm site. 4. Summary of Effects and Recommendations to Reduce Impacts Best management practices are recommended by the Wyoming Game and Fish Department (2010), U.S. Fish and Wildlife Service Wind Turbine Guidelines Advisory Committee (2010b) and the U.S. Fish and Wildlife Service Ecological Services (2010a). In addition to these recommendations, site- specific recommendations derived from the summer and fall 2010 surveys are provided below. These recommendations augment, but do not substantially change the recommendations provided in the final report on the first year of survey work (Kieweg et al. 2010). A second season of surveys will be completed prior to construction of the wind farm and these recommendations may be consequently revised. 4.1. Bats and Collision Risk Four species of bats were documented on site, including two migratory forest bats (Hoary Bat and Eastern Red Bat). These species have had significant documented mortality at other sites including the nearby Foote Creek Rim site (Young et al. 2003), creating a strong possibility of some mortality at the Boswell Springs site, but the levels are likely to be similar to or lower than at Foote Creek Rim and similar to that at other wind farms which are properly sited to avoid known migratory pathways and bat concentration areas.
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 11
a. AES recommends that wind turbines be set back from the stream and significant wetland areas due to the higher quality bat habitat occurring there compared to sagebrush and grassland habitats. b. AES recommends that the wind farm operator annually review the latest findings on ways to reduce migratory forest bat mortality at wind farms. Research has shown that changing the rotor start-up speed or altering the pitch angle of the blade can reduce bat mortality 50-70% without significantly compromising production (Baerwald et al. 2009). Findings from lower wind areas, such as the Midwest, may not be as useful in higher wind areas. c. We recommend that mortality reduction measures be considered as they are developed. These measures should be proven to significantly reduce migratory forest bat mortality in a cost-effective way. d. Conduct a one-year post construction mortality study for bats to validate the expectations of this study. 4.2. Risk to Nesting Raptors One occupied raptor nest, a Ferruginous Hawk nest, was found in the northeast corner of the site. No other occupied raptor nests were found on the site. • Place turbines 1600m from occupied raptor nests. • Discuss management concerns for Ferruginous Hawk with USFWS and WGFD. 4.3. Risk to Amphibians and Reptiles Two amphibians, Boreal Chorus Frog and Tiger Salamander, were confirmed in several riparian and wetland areas on site. They are likely present throughout the site in wetland and riparian areas. No other amphibian or reptile species were observed, although surveys were not exhaustive and small populations of other reptile and amphibian species may be present. • Advise employees on site to drive with caution during peak movement periods for amphibians and reptiles. 4.4. Risk to Birds Utilizing Wheatland Reservoir No. 3 Although there is considerable use of the Wheatland Reservoir by waterfowl species, and many records of SGCN species at the site, there are no apparent flight paths between the reservoir and the site. Species using the reservoir typically remain on or above the open water and collision risk would be limited. , and collision risk with the wind farm would be limited to the possibility of collisions during ascent or descent from the reservoir during inclement weather conditions. • Set turbines back 800m from Wheatland Reservoir No. 3.
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 12
5. Literature Cited Arnett, E.B. 2005. Relationship between bats and wind turbines in Pennsylvania and West Virginia: an assessment of fatality search protocols, patterns of fatality, and behavioral interactions with wind turbines. Unpublished report. Bats and Wind Energy Cooperative, Bat Conservation International, Austin TX. Arnett, E. B., J. P. Hayes and M. M. P. Huso. 2006. An evaluation of the use of acoustic monitoring to predict bat fatality at a proposed wind facility in south-central Pennsylvania. An annual report submitted to the Bats and Wind Energy Cooperative. Bat Conservation International, Austin, TX. Arnett, E.B., W.K. Brown, W.P. Erickson, J.K. Fiedler, B.L. Hamilton, T.H. Henry, A. Jain, G.D. Johnson, J. Kerns, R.R. Koford, C.P. Nicholson, T.J. O’Connell, M.D. Piorkowski and R.D. Tankersley Jr. 2008. Patterns of bat fatalities at wind energy facilities in North America. Journal of Wildlife Management 72:61-78. Baerwald, E.F., G.H. D’Amours, B.J. Klug and R.M.R. Barclay. 2008. Barotrauma is a significant cause of bat fatalities at wind turbines. Current Biology 18:695-696. Baerwald, E.F. and R.M.R. Barclay. 2009 Geographic variation in activity and fatality of migratory bats at wind energy facilities. Journal of Mammalogy 90:1341-1349. Baerwald, E.F., J. Edworthy, M. Holder and R.M.R Barclay. 2009. A large-scale mitigation experiment to reduce bat fatalities at wind energy facilities. Journal of Wildlife Management 73:1077-1081. Barclay, R. M. R. 1995. Does energy or calcium availability constrain reproduction in bats? Symposium of the Zoological Society of London 67:245-258. Bat Conservation International. 2009. Species and profiles. http://www.batcon.org/index.php/education/article-and-information/species-profiles.html (Accessed 2009). Bat Conservation International. 2010. White-nose Syndrome. http://www.batcon.org/index.php/what-we-do/white-nose- syndrome/subcategory/intro.html (Accessed 2010). Bogdanowicz, W. 1994. Myotis daubentonii. Mammalian Species 475:1-9. Brigham, R. M. 1991. Flexibility in foraging and roosting behavior by the Big Brown bat (Eptesicus fuscus). Canadian Journal of Zoology 69: 117-121. Carter, T. D. 1950. On the migration of the Red Bat, Lasiurus borealis. Journal of Mammalogy 31:349-350. Chapman, S.S., S.A. Bryce, J.M. Omernik, D.G. Despain, J. ZumBerge and M. Conrad. 2004. Ecoregions of Wyoming (color poster with map, descriptive text, summary tables, and photographs). U.S. Geological Survey (map scale 1:1,400,000), Reston, Virginia. http://www.epa.gov/wed/pages/ecoregions/wy_eco.htm#Ecoregions%20denote (Accessed 2009). Cryan, P. M. 2003. Seasonal distribution of migratory Tree Bats (Lasiurus and Lasionycteris) in North America. Journal of Mammalogy 84:579-593. Cryan, P.M. and J.P. Veilleux. 2007. Migration and use of autumn, winter, and spring roosts by Tree Bats. In M.J. Lacki, J. P. Hayes and A. Kurta (eds.). Bats in forests: Conservation and management, p. 153-175. Johns Hopkins University Press, Baltimore, MD.
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Cryan, P.M. 2008. Mating behavior as a possible cause of bat fatalities at wind turbines. Journal of Wildlife Management 72:845-849. Cryan, P.M. and R.M.R. Barclay. 2009. Causes of bat fatalities at wind turbines: Hypotheses and predictions. Journal of Mammalogy 90:1330-1340. Eckert, H. G. 1982. Ecological aspects of bat activity rhythms. In T. H. Kunz, editor. Ecology of bats, p. 201-242. Plenum Press, New York. Erickson, J. L. and S. D. West. 2002. The influence of regional climate and nightly weather conditions on activity patterns of insectivorous bats. Acta Chiropterologica 4:17-24. Fiedler, J. K. 2004. Assessment of bat mortality and activity at Buffalo Mountain Windfarm, eastern Tennessee. M.S. Thesis. University of Tennessee, Knoxville, TN. Furlonger, C. L., H. J. Dewar and M. B. Fenton. 1987. Habitat use by foraging insectivorous bats. Canadian Journal of Zoology 65:284-288. Griffin, D.R. and D. Thompson. 1982. High altitude echolocation of insects by bats. Behavioral Ecology and Sociobiology, Springer. Gruver, J. C. 2002. Assessment of bat community structure and roosting habitat preferences for the Hoary Bat (Lasiurus cinereus) near Foote Creek Rim, Wyoming. Thesis. University of Wyoming, Laramie, WY. Hall, E.R. 1946. Mammals of Nevada. University of California Press, Berkeley CA. Hall, J.S. 1962. A life history and taxonomic study of the Indiana Bat, Myotis sodalis. Reading Public Museum and Art Gallery Scientific Publications 12:1-68. Hayes, J.P. 1997. Temporal variation in activity of bats and the design of echolocation-monitoring studies. Journal of Mammalogy 78:514-524. Horn, J.W., E.B. Arnett and T.H. Kunz. 2008. Behavioral responses of bats to operating wind turbines. Journal of Wildlife Management 72:123-132. Jaberg, C., C. Leuthold and J.D. Blant. 1998. Foraging habitats and feeding strategy of the Parti- coloured Bat Vespertilio murinus L., 1758 in Western Switzerland. Myotis 36:51-61. Jackson, H.H.T. 1961. Mammals of Wisconsin. University of Wisconsin Press, Madison WI. Jain, A. A. 2005. Bird and bat behavior and mortality at a northern Iowa windfarm. Thesis. Iowa State University, Ames, IA. Johnson, G. D., M. K. Perlik, W. E. Erickson and M. D. Strickland. 2004. Bat activity, composition, and collision mortality at a large wind plant in Minnesota. Wildlife Society Bulletin 32:1278- 1288. Johnson, G.D. 2005. A Review of bat mortality at wind-energy developments in the United States. Bat Research News 46:45-49. Kalcounis, M.C., K.A. Hobson, R.M. Brigham and K.R. Hecker. 1999. Bat activity in the Boreal forest: importance of stand type and vertical strata. Journal of Mammalogy 80:673–682. Kieweg, H., D. Mensing and K. Chapman. 2010. Assessment of wind energy and wildlife interactions at Boswell Springs Wind Farm. Applied Ecological Services, Inc. Prior Lake, MN. Kurta, A., G. P. Bell, K. A. Nagy and T. H. Kunz. 1989. Water balance of free-ranging :Little Brown Bats (Myotis lucifugus) during pregnancy and lactation. Canadian Journal of Zoology 67: 2468-2472.
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Kurta, A., T. H. Kunz and K. A. Nagy. 1990. Energetics and water flux of free-ranging Big Brown Bats (Eptesicus fuscus) during pregnancy and lactation. Journal of Mammalogy 71: 59-65. Kurta, A. 1995. Mammals of the Great Lakes Region. University of Michigan Press, Ann Arbor, MI. Kurta, A., L. Winhold, J.O. Whitaker, Jr. and R. Foster. 2007. Range expansion and changing abundance of the Eastern Pipistrelle (Chiroptera: Vespertilionidae) in the central Great Lakes region. American Midland Naturalist 157: 404–411. Larkin, R.P. 2006. Migrating bats interacting with wind turbines: What birds can tell us. Bat Research News 47:23-32. Larson, D. J. and J. P. Hayes. 2000. Variability in sensitivity of AnaBat II bat detectors and a method of calibration. Acta Chiropterologica 2: 209–213. Lumsden, L. F. and A. F. Bennett. 1995. Bats of a semiarid environment in south-eastern Australia; biogeography, ecology and conservation. Wildlife Research 22: 217-240. Miller, B.W. 2001. A method for determining relative activity of free flying bats using a new activity index for acoustic monitoring. Acta Chiropterologica 3:93–105. Mumford, R.E. and J.O. Whitaker, Jr. 1982. Mammals of Indiana. Indiana University Press, Bloomington, IN. Murray, S.W. and A. Kurta. 2004. Nocturnal activity of the endangered Indiana Bat (Myotis sodalis). Journal of Zoology 262:197-206. NatureServe. 2010. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.0. NatureServe, Arlington, VA. http://www.natureserve.org/explorer (Accessed 2010). O’Farrell, M. J. and W. L. Gannon. 1999. A comparison of acoustic versus capture technique for the inventory of bats. Journal of Mammalogy 80:24-30. O'Shea, T.J. and M.A. Bogan. 2003. Monitoring trends in bat populations of the United States and territories: Problems and prospects. U.S. Geological Survey, Biological Resources Discipline, Information and Technology Report, USGS/BRD/ITR-2003-0003:1-274. Peurach, S.C. 2003. High-altitude collision between an airplane and Hoary Bat, Lasiurus cinereus. Bat Research News 44:2-3. Redell, D., E. B. Arnett, J. P. Hayes and M. M. P. Huso. 2006. Patterns of pre-construction bat activity determined using acoustic monitoring at a proposed wind facility in south-central Wisconsin. A final report submitted to the Bats and Wind Energy Cooperative. Bat Conservation International, Austin, TX. Reynolds, D. S. 2006. Monitoring the potential impact of a wind development site on bats in the Northeast. Journal of Wildlife Management: in press. Swewczak, J. M., S. M. Szewczak, M. L. Morrison and L. S. Hall. 1998. Bats of the White and Inyo Mountains of California-Nevada. Great Basin Naturalist 58: 66-75. Thomas, D. W. 1988. The distribution of bats in different stages of Douglas-fir forests. Journal of Wildlife Management 52:619-626. Thomas, O. 1921. Bats on migration. Journal of Mammalogy 2:167. U.S. Fish and Wildlife Service (USFWS) - Ecological Services. 2010a. Wind energy development: Best management practices for migratory birds. USFWS, Wyoming Ecological Services Field Office, Cheyenne, WY.
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U.S. Fish and Wildlife Service (USFWS) – Wind Turbine Guidelines Advisory Committee. 2010b. Preamble and policy recommendations. http://www.fws.gov/habitatconservation/windpower/wind_turbine_advisory_committee.h tml (Accessed 2010). Verboom B. and H. Huitema. 1997. The importance of linear landscape elements for the Pipistrelle Pipistrellus pipistrellus and the Serotine Bat (Eptesicus serotinus). Landscape Ecology 12:117-125. Weller T.J. 2007. Assessing population status of bats in forests: Challenges and opportunities. In M.J. Lacki, J.P. Hayes and A. Kurta (eds.). Bats in forests: Conservation and management. Johns Hopkins University Press, Baltimore, MD. Wyoming Game and Fish Department (WGFD). 2010. Wildlife protection recommendations for wind energy development in Wyoming. March 19, 2010 Draft. Cheyenne, WY. Wyoming Natural Diversity Database (WYNDD). 2009. Data compilation for H. Kieweg, completed February 20, 2009. Unpublished report. Wyoming Natural Diversity Database, University of Wyoming, Laramie WY. Young, D.P., W.P. Erickson, R.E. Good, M.D. Strickland and G.D. Johnson. 2003. Final report: Avian and bat mortality associated with the initial phase of the Foote Creek Rim Windpower Project, Carbon County, Wyoming November 1998-June 2002. Western EcoSystems Technology, Inc. http://www.west-inc.com/reports/fcr_final_mortality.pdf (Accessed July 2010). Zinn, T.L. and W.W. Baker. 1979. Seasonal migration of the Hoary Bat, Lasiurus cinereus, through Florida. Journal of Mammalogy 60:634-635.
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Map Exhibit 1. Site Location & Bat Acoustic Monitoring Locations
Map Exhibit 2. Raptor Nest Locations
Map Exhibit 3. Amphibian and Reptile Locations
Appendix 1. Acoustic Bat Data Voucher Calls
1. Big Brown Bat (Eptesicus fuscus), 7/01/2010, 03:06, Site 2, 3 meter tripod.
2. Myotis species, 5/28/2010, 00:32, Site 1, 3 meter tripod.
3. Hoary Bat (Lasiurus cinereus), 5/28/2010, 00:44, Site 1, 3 meter tripod.
4. Unidentifiable <35kHz, 6/25/2010, 02:11, Site 2, 3 meter tripod.
5. Eastern Red Bat (Lasiurus borealis), 8/14/2010, 21:54, Site 4, 3 meter tripod.
6. Pallid Bat (Antrozous pallidus), 6/28/2010, 01:10, Site 2, 3 meter tripod.
7. Unidentifiable >35kHz, 6/24/2010, 23:57, Site 2, 3 meter tripod.
Appendix 2. Site Photographs
Site 1. Playa Pond on Grassland
Site 2. Small Reservoir
Site 3. Sagebrush
Site 4. Wetland/ Small Creek
Site 5. Grassland with Rock Outcropping
Site 6. Grassland
Site 7. Reservoir and Wetland Area
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm ALBANY COUNTY, WYOMING
Submitted to: Mr. Paul Martin, Intermountain Wind PO Box 353 Boulder, CO 80306
Prepared by: Heather Kieweg, Doug Mensing and Kim Chapman Applied Ecological Services, Inc. 21938 Mushtown Road, Prior Lake, Minnesota 55372 Phone: (952) 447-1919, Fax: (952) 447-1920 Email: [email protected]
August 17, 2010
AES # 08-0853 AES # 08-0853
TABLE OF CONTENTS
1. Introduction ...... 1 1.1. Project Description ...... 1 1.2. Wildlife and Habitat at Boswell Springs Wind Farm ...... 1 1.3. Wind Development Regulations and Guidance ...... 2 1.3.1. Endangered and Threatened Species ...... 2 1.3.2. Bald and Golden Eagle Protection Act...... 2 1.3.3. Migratory Bird Treaty Act ...... 2 1.3.4. Bats ...... 2 1.3.5. Wind Development Guidance ...... 2 1.3.6. Other Regulations ...... 3 1.4. Communications with Wildlife Agencies ...... 3 2. Study Approach and Methods ...... 4 2.1. Recommended Biological Surveys, Studies and Mapping ...... 4 2.2. Habitat Cover Mapping & Point Selection ...... 6 2.3. Endangered and Threatened Species ...... 7 2.4. Bald and Golden Eagles ...... 7 2.5. Native and Sensitive Bird Species ...... 7 2.5.1. Field Methods ...... 8 2.5.2. Data Analysis ...... 10 2.6. Bats and Collision Risk ...... 11 2.7. Species of Greatest Conservation Need ...... 12 2.7.1 White-tailed Prairie Dog ...... 12 3. Results and Discussion ...... 12 3.1. Habitat ...... 12 3.2. Endangered and Threatened Species ...... 13 3.2.1. Mountain Plover ...... 13 3.2.2 Black-footed Ferret ...... 14 3.3. Bald and Golden Eagles ...... 14 3.4. Native and Sensitive Bird Species ...... 15 3.4.1. Collision Risk ...... 15 3.4.2. Habitat Displacement Risk ...... 21 3.5. Bat Habitat Based Risk Analysis ...... 22 3.6. Species of Greatest Conservation Need ...... 24 3.6.1. McCown’s Longspur ...... 24 3.6.2. Brewer’s Sparrow ...... 24 3.6.3. Ferruginous Hawk ...... 25 3.6.4. Lark Bunting ...... 25 3.6.5. White-tailed Prairie Dogs ...... 26 3.6.6. Amphibians and Reptiles ...... 26 4. Summary of Effects and Recommendations to Reduce Impacts ...... 28 4.1. Endangered and Threatened Species ...... 28 4.3. Native and Sensitive Bird Species ...... 28 4.2. Bald and Golden Eagles ...... 28 4.3.1. Native, Sensitive and Long-distance Migrant Bird Species Collision Risk ...... 28 4.3.2 Habitat Displacement Risk ...... 29 4.4 Bats and Collision Risk ...... 29 4.5 Species of Greatest Conservation Need ...... 29 5. Literature Cited ...... 30
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm i
TABLES Table 1. WYGF & USFWS Recommended Biological Surveys, Studies and Mapping...... 4 Table 2. AES habitat cover type descriptions...... 6 Table 3. Habitat types, number of sampling points (P) and number of surveys (N) by survey type for the first study season...... 7 Table 4. Dates of bird surveys at Boswell Springs...... 9 Table 6. Land Cover at proposed Boswell Springs site...... 13 Table 7. Native, sensitive, and long-distance migrant mean abundance and mean richness by habitat on-site during spring and fall passerine migration and breeding bird surveys1...... 17 Table 8. Native, sensitive, and long-distance migrant mean abundance and mean richness on-site and in reference area during fall passerine migration surveys...... Error! Bookmark not defined. Table 9. Raptor abundance by survey...... 20 Table 10. Bat habitat-based risk analysis...... 23 Table 11. Amphibian and reptile habitat-based risk analysis...... 27
MAP EXHIBITS Map Exhibit 1. Site Location & Survey Points Map Exhibit 2. Site Habitats Map Exhibit 3. Winter Bird Locations Map Exhibit 4. Raptor Nest Locations Map Exhibit 5. Interpreted Prairie Dog Population Density Map Exhibit 6. Sensitive Areas
APPENDICES APPENDIX 1. SITE REVIEW APPENDIX 2. PER-POINT ABUNDANCE OF BIRDS SURVEYED DURING ALL POINT-COUNT SURVEYS ON SITE APPENDIX 3. PER-POINT ABUNDANCE OF BIRDS SURVEYED DURING FALL PASSERINE AND FALL RAPTOR SURVEYS APPENDIX 5 . USFWS SITE DEVELOPMENT AND CONSTRUCTION BEST MANAGEMENT PRACTICES (USFWS – WIND TURBINE GUIDELINES ADVISORY COMMITTEE 2010) APPENDIX 6. WIND ENERGY DEVELOPMENT: BEST PRACTICES FOR MIGRATORY BIRDS (USFWS – ECOLOGICAL SERVICES 2010)
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm ii EXECUTIVE SUMMARY The proposed Boswell Springs Wind Farm and associated phases (“site”) constitutes about 34 square miles of primarily Grassland and Upland shrub-scrub habitat. Elevations range from 6,713 to 7,192 feet, in the Rolling Sagebrush Steppe of the Wyoming Basin. Wetlands primarily follow riparian corridors throughout the site and a few reservoirs of open water occur along Seven-Mile Creek and Spring Creek. The topography is generally flat except for along the watercourses where it descends 60 to 80 feet. Preliminary plans are for 80-100m high turbines with 77-90m diameter blades. AES communicated with the Wyoming Game and Fish Department (WGFD) and U.S. Fish and Wildlife Service (USFWS) and to develop biological surveys that would characterize risks to wildlife at the site from wind development. Issues of concern included migrating passerines and raptors, breeding birds, Sage Grouse, bats, amphibians and reptiles, White-tailed Prairie Dog distribution and influence of Wheatland Reservoir on the site. AES coordinated methods with the WGFD and USFWS to investigate these concerns. The resulting surveys included a spring passerine survey, a spring raptor survey, a breeding bird survey, a fall passerine survey, a fall raptor survey, a winter bird survey, an aerial raptor nest search and nest monitoring, Sage Grouse lek surveys, bat habitat analysis, bat acoustic monitoring, analysis of Species of Greatest Conservation Need, amphibian and reptile habitat analysis, amphibian and reptile incidental observations, priority watershed mapping, White- tailed Prairie Dog concentration mapping and observations at Wheatland Reservoir. The bird surveys were conducted from April 2009 to April 2010. The bat acoustic monitoring is ongoing and results will be reported in an addendum to this report. Surveys in fall 2010 were paired with surveys in a reference area, which will be used as a control after construction. A second season of surveys will be completed prior to construction in order to validate the preliminary results reported here. Mountain Plover have been recently proposed for listing as a threatened species. There are historic records from the 1990’s on the site along Fetterman Road. No Mountain Plovers were found during the three survey periods conducted during the recommended search period, however no Mountain Plover specific surveys following USFWS survey protocol have been completed, and it is possible that Mountain Plover may be present at the site, but undetected. Golden Eagles were sighted on the site in the spring migration, breeding bird and fall migration surveys. Golden Eagles were found nesting 1.5 miles southwest of the site, and two additional nests that were unoccupied at the time of the survey were found near the site. Golden Eagle distribution did not correlate with White-tailed Prairie Dog distribution. Bald Eagles were observed twice during the fall migration. Given the lack of Golden Eagle mortality at the nearby Foote Creek Rim (FCR) facility and the limited use of the site by Bald Eagles collision risk for these species is very low. Passerine migrants were counted at 25 survey points in spring, breeding season and fall. Raptors were counted at 6 survey points in the spring and the fall. In all point count surveys, 42 different species were observed on site, and an additional species was observed in the reference area. Of the species seen on site 18 (43%) were classed as sensitive species (species at risk due to existing factors), and the additional species seen in the reference area was considered sensitive. This number is higher than expected and is due to the presence of species which are in decline regionally, but common elsewhere in their range (e.g., Mallard, Barn Swallow and Northern Shoveler). The most commonly observed species throughout the site, constituting 70% of individuals seen, were Horned Lark, Mallard, McCown’s Longspur, Blue-winged Teal, Green-winged Teal, Northern Shoveler, Gadwall, Western Meadowlark, Violet-green Swallow and Vesper Sparrow. The greatest abundance and richness of native birds, sensitive species and long-distance migrants (i.e., “neotropical migrants”) occurred at wetland points in riparian corridors. The Grassland and Upland shrub-scrub points had a significantly lower abundance and richness of native bird species, long- distance migrants, and significantly lower richness of sensitive species. Sensitive species abundance was lower at Grassland and Upland shrub-scrub points, but the difference was not significant.
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm iii
Raptors were present in low abundance at the site throughout the year. On average, 1.67 raptors were recorded per hour of observation. The site does not appear to be a raptor concentration area, but on some days the site may experience an elevated raptor passage rate as a broad front of raptors passes through the area. The most common raptor species on the site were Golden Eagle, Ferruginous Hawk and Northern Harrier. Golden Eagle and Ferruginous Hawk are both raptor species of concern to the USFWS. Two nests that are probably Red-tailed Hawk nests, one nest on a ledge that is possibly a Ferruginous Hawk nest and a possible nest on a structure were found on the site during the aerial survey. All of these nests were unoccupied at the time of the survey. In the reference area there are nests and possible nests of Golden Eagle, Ferruginous Hawk, Red-tailed Hawk and Swainson ’s Hawk. Two species, Vesper Sparrow and Northern Harrier, thought to be potentially sensitive to habitat displacement from wind development were found. These species are not declining in the BBS region nor are they SGCN species. Area sensitivity has not been studied for the McCown’s Longspur which is an SGCN species and abundant on the site in all habitats. The rarer Lark Bunting, also an SGCN species, may be area sensitive. Placement of turbines may result in shifting of territories or a reduction of nesting density for these species. No signs of Sage Grouse were observed during the 2009 grouse surveys, and all historical lek locations were unoccupied at the time of the surveys. The site lies outside the designated Sage Grouse Core Areas. Bat habitat risk analysis identified Big Brown Bat, Fringed Myotis and Western Small-footed Myotis as the species most likely to occur on the site. None of these species are known to be particularly sensitive to wind development. Results of ongoing bat acoustic monitoring will provide data on the site’s bat community and be included as an addendum to this report. Nine bird Species of Greatest Conservation Need (SGCN) were observed on the site. These species do not have a protected legal status, but it is recommended that impacts to these species be avoided or mitigated where possible. Of the nine species McCown’s Longspur, Brewer’s Sparrow, Ferruginous Hawk and Lark Bunting were likely to be breeding on the site. McCown’s Longspur was common on the site, and has the potential to for direct collision mortality due to its sky-larking territorial displays, although these are typically below the rotor swept area. To date Boreal Chorus Frogs are the only species of amphibians and reptiles confirmed on the site. Amphibian and reptile species that are likely to use the Grassland and Upland shrub-scrub communities include Bullsnake, Greater Short-horned Lizard and Prairie Rattlesnake. Incidental observations for these species will continue to be made through October 2010. Whit-tailed Prairie Dogs were located in grasslands throughout the site. Prairie dogs were densest in grassland areas and least dense in Upland shrub-scrub habitats and along riparian corridors. Prairie dog density did not correspond to raptor abundance. Given these findings, specific recommendations focus on avoiding known sensitive areas, particularly wetlands along riparian corridors and wetlands over 5 acres in size. Possible presence of Mountain Plover at the site should be discussed with USFWS. Management concerns for the Golden Eagle and Ferruginous Hawk should be discussed with the USFWS and WGFD. Concerns for SGCN species—McCown’s Longspur, Brewer’s Sparrow, Ferruginous Hawk, Lark Bunting—should be discussed with the WGFD. Post-construction mortality surveys should be conducted for birds and bats, and post-construction point count surveys completed to document density changes of Vesper Sparrow and McCown’s Longspur using the BACI approach. Other general recommendations for wind farm design and operation are provided based on federal and state guidance. These recommendations will be reassessed after the completion of a second year of studies prior to the construction of the wind farm.
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ACKNOWLEDGEMENTS Intermountain Wind and Applied Ecological Services thank Scott Gamo, John Emmerich, Matt Fry and Mary Flanderka of the Wyoming Game and Fish Department for their guidance in using the Wyoming survey protocols and refining the survey methods used in the field. Scott Covington and Patricia Sweanor of the USFWS were very helpful in developing the raptor nest search and observation approach, as well as in identifying their issues of concern. We also thank Amber Travsky of Real West Natural Resource Consulting and Caitlin Coberly of Merlin Environmental, LLC, who contributed significantly to this study through their extensive field work.
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm v 1. Introduction Intermountain Wind retained Applied Ecological Services, Inc. (AES) to provide site review and biological surveys for a potential wind farm in central Albany County, Wyoming (Map Exhibit 1). In spring 2009, AES completed a Site Review for the site, which detailed potential issues and survey requirements (Appendix 1). AES conducted a season of biological surveys at the site from spring 2009 through Spring 2010. A second season of surveys will be completed prior to construction of the wind farm. This report summarizes methods and results of the first season’s biological surveys, discusses the implications of these surveys for the development of the wind farm site, and provides recommendations for avoiding and minimizing biological impacts. 1.1. Project Description The proposed Boswell Springs Wind Farm (the “site”) is an approximately 34 sq mi area located 40 miles northwest of Laramie, Wyoming (Map Exhibit 1). Design specifications for the wind turbines have not been completed. The turbines are expected to be 1-2 MW, with tower heights of 80-100m and rotors of approximately 77-90m diameter. Based on these dimensions, the upper limit of the rotor swept area (RSA) would be 118m to 145m, and the lower limit of the RSA would be from 35m to 62m. 1.2. Wildlife and Habitat at Boswell Springs Wind Farm The site is located in the Rolling Sagebrush Steppe of the Wyoming Basin. The basin is a broad intermontane region dominated by grasslands and shrublands that often are big sagebrush shrublands. Precipitation averages from 6 to 16 inches per year. The topography consists of rolling plains, with hills, cuestas, mesas and terraces. The site is relatively flat, but a westward-flowing watercourse descends 60 to 80 feet through the center of the site along Seven-mile Creek and to a lesser extent Spring Creek. Elevations range from 6,713 to 7,192ft (2,046 to 2,192m). South and east of the site the terrain descends to Rock Creek, and to the northeast of the site the landscape ascends and transitions into foothills of the Laramie Mountains. Sagebrush still dominates most of the region, but invasive European annual grasses are replacing sagebrush in some areas (Chapman et al. 2004). The site itself is dominated by grassland with pockets of high quality sagebrush in the northwestern and northeastern portions of the site. Riparian emergent wetlands occur along Seven-mile Creek and Spring Creek, and isolated emergent wetlands are scattered throughout the site. There are a few small reservoirs with open water along these creek corridors. While there are no large bodies of open water within the site, the Wheatland No. 3 Reservoir is located just southeast of the site. Development in the area supports cattle ranching. Stock handling areas, roads and fences, and stock ponds and reservoirs are the main constructed features. Conditions for wildlife are typical of ranching country that contains scattered development. Pronghorn antelope are the most frequently observed large game. The amount of forage available to wildlife on the site is less than would be expected with ungrazed conditions. Consequently, small mammal populations comprising the base of the food chain may be different than with ungrazed conditions. This may affect raptor populations. However, White-tailed Prairie Dogs use the site extensively. Some habitat fragmentation has occurred due to roads and development, but large, continuous habitat blocks remain and are expected to support species that may decrease with habitat fragmentation. Overall, wildlife at the site is representative of the region’s grasslands and shrub-scrub habitats.
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1.3. Wind Development Regulations and Guidance
1.3.1. Endangered and Threatened Species Endangered and Threatened (ET) species are protected at the federal level under the Endangered Species Act (ESA). The federal ESA protects listed species and their habitats. There is a mechanism to grant permission for incidental takings under the ESA. The state of Wyoming only protects federally listed species, and does not maintain a separate state endangered and threatened species list. However, nongame wildlife is protected under WGFD Regulation Chapter 52 Nongame Wildlife.
1.3.2. Bald and Golden Eagle Protection Act The Bald and Golden Eagle Protection Act (BGEPA) assigns legal authority to the U.S. Fish and Wildlife Service (USFWS) to protect Bald and Golden Eagles from takings and disturbance. Rules for the issuance of permits under the BGEPA were finalized on September 11, 2009 (USFWS 2009). Permitted activities do not distinguish between lethal and non-lethal take and activities that affect individual eagles or important eagle use areas are regulated. The BGEPA permitting process limits the number of permits issued for bald eagles under the BGEPA in each region to estimated 5% of annual productivity for the regional population and provides separate provisions for a programmatic take permit versus individual instances of a take. Programmatic take permits are issued for projects that undertake activities that may disturb or otherwise take eagles on an on-going basis and generally incorporate the implementation of Advanced Conservation Practices, the development of Avian Protection Plans or Wildlife Hazard Management Plans as a condition of the permit. In addition, this permit type also requires basic post-activity monitoring. Individual or “one time” take permits are issued for the removal of eagle nests, direct take of individual eagles, and grandfathered incidental take permits issued under Section 7 of the Endangered Species Act.
1.3.3. Migratory Bird Treaty Act The Migratory Bird Treaty Act (MBTA) assigns legal authority to the US Fish and Wildlife Service (USFWS) to protect migratory birds from takings. These migratory birds include over 800 species of raptor, diurnal migrant, and passerine migrant. The MBTA only regulates direct takings, and not habitat modifications. The level of direct taking by a wind energy facility which would invoke prosecution under the MBTA has not been established. There is currently no mechanism to grant permission for incidental takings under the MBTA. The USFWS believes that it has the authority to create a process similar to that developed for the BGEPA under the MBTA, but has not begun to develop the necessary regulations (USFWS 2008b).
1.3.4. Bats At the federal level, bats are only protected if they are listed as endangered or threatened, and no federally protected bat species are expected to use the site. Since 1994 bats have been protected in Wyoming as part of nongame wildlife regulation – chapter 52. All bat species are protected from intentional take unless approved by the WGFD for control measures to address public health or human safety concerns.
1.3.5. Wind Development Guidance Guidance, recommendations and regulations regarding wind project development and wildlife impacts are still being developed and are constantly changing. The USFWS Wind Turbine Guidelines Advisory Committee completed its recommended guidelines to mitigate impacts to wildlife and their habitats related to land-based wind energy facilities on March 4, 2010. These guidelines are now pending approval by the Secretary of the Interior and are expected to be drafted into final recommendations by the USFWS in the near future. These guidelines outline a tiered
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research approach that includes searches of existing literature and data to identify potential issues of concern, field studies to provide additional data where necessary, and post-construction mortality studies to identify and quantify impacts. This guidance document recommends that wind developers voluntarily adhere to these guidelines and communicate with the USFWS as part of their due diligence process in order to avoid, minimize and mitigate impacts to species protected under the BGEPA and MBTA. It also suggests that the USFWS should use its discretion with regard to prosecution under these acts (USFWS 2010b). In 2003 the USFWS published Interim Voluntary Guidelines (USFWS 2003) which outlined recommendations for site and turbine design and operations and presented a quantitative method for initial site evaluation. The 2003 guidelines were not widely used and the 2010 guidelines will replace them. The USFWS guidelines target “species of concern” and “species of habitat concern.” The guidelines define a species of concern as “any species which is listed as an endangered, threatened or candidate species under the Endangered Species Act, is subject to the Migratory Bird Treaty Act or Bald and Golden Eagle Protection Act, or is designated by law, regulation or other formal process for protection and/or management by the relevant agency or other authority, or has been shown to be significantly adversely affected by wind energy development, and ii) is determined to be possibly affected by the project.” It defines species of habitat fragmentation concern as those “whose genetic or demographic viability is reduced by separation of their habitats into smaller blocks, thereby reducing connectivity, and for which habitat fragmentation from a wind development project may create significant barriers to genetic or demographic viability of the affected population.” At the state level, the Wyoming Game and Fish Department (WGFD) have developed state-wide recommendations for wind developments. These recommendations have been published in draft form (WGFD 2010). These recommendations provide guidance on best management practices, baseline data collection and monitoring. While these are only recommendations, the WGFD does make an assessment of impacts to the Wyoming Industrial Siting Council (WISC) as part of the WISC permitting process, and advises wind energy developers regarding surveys and mitigations at wind farms. To date the WGFD has not found unacceptable impacts in proposed wind energy development projects submitted to the WISB. However, WGFD has negotiated with wind energy developers prior to and during the approval process in order to establish a scientifically valid set of baseline data and to avoid and minimize wildlife impacts that might have resulted from specific turbine siting plans.
1.3.6. Other Regulations Additional federal involvement may be triggered through the Clean Water Act (1972), National Historic Preservation Act (1966) and National Environmental Policy Act (NEPA 1969). The US Army Corps of Engineers (USACE) has permitting authority over proposed impacts to federally protected Waters of the United States, including many wetlands. Wetlands are also protected at the state level by the Wyoming Department of Environmental Quality (WYDEQ). Cultural resources are protected at the state level by the State Historic Preservation Office (SHPO) in collaboration with the federal Advisory Council on Historic Preservation. Federal permitting through the USACE or SHPO may trigger NEPA review of a proposed wind project. 1.4. Communications with Wildlife Agencies Initial wildlife concerns identified in an email to Paul Martin from Vern Stetler dated March 21, 2008 identified Antelope crucial winter ranges and occupied and historic sage grouse leks as issues of concern at the site. AES met with Scott Gamo and Matt Fry May 19, 2009 to discuss recommended studies for this site. Initial studies were already underway, and the WGFD was in the process of drafting recommendations for baseline data collection. The first round of AES studies from March-June 2009 was completed as planned simultaneous with the release of the WGFD recommendations, and
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therefore the recommendations could not be fully accommodated, which WGFD acknowledged. From that point forward, WGFD recommended that the survey protocols in the recommendations be followed. AES detailed plans for biological surveys in a letter to Scott Gamo at the WGFD dated August 25, 2009. This letter proposed that the first round of studies be incorporated into the first year of construction monitoring despite differences in protocol from the new WGFD recommendations, and that future work would follow the new WGFD recommendations. The first year of survey work was completed on 2009-2010 and results from these surveys are reported here. The second year of survey work will be completed in the year prior to construction to provide further baseline data for the site. John Emmerich of WGFD responded with comments on October 2, 2009. This letter approved proposed study protocols with the request for further coordination on bat survey protocols and additional attention to newly developed water and stream monitoring protocols. In February-March 2010, AES communicated with Scott Covington and Patricia Sweanor of the USFWS regarding raptor nest searching and monitoring protocols. AES’s survey protocols were communicated to the USFWS. In a phone conversation with Scott Gamo of WGFD and Paul Martin (Intermountain Wind) on March 22, 2010, AES further discussed study protocols including bats, wetlands and riparian areas, big game, reptiles and amphibians, and Species of Greatest Conservation Concern. 2. Study Approach and Methods 2.1. Recommended Biological Surveys, Studies and Mapping Table 1 provides the dates and summary descriptions of biological surveys recommended for the site. More detailed methods for selected surveys are provided in the following pages.
Table 1. WYGF & USFWS Recommended Biological Surveys, Studies and Mapping. Survey Dates Description Comments
Federal ET Species – No Studies Required
BGEPA & MBTA Fixed-wing aircraft survey to detect Second year of study to Raptor Nest raptor nests and evidence of raptor April 26, 2010 be completed prior to Search breeding; site and reference area construction surveyed on 0.5 minute transects. Results to be reported in Monitor raptor activity to determine report addendum. Second Raptor Nest June-July 2010 flight paths in the areas of known year of study to be Monitoring nests. completed prior to construction 3 survey periods; 30-minute point count surveys; 9am-4pm; point Second year of study to Spring Raptor April 10,11 & 16, density 1 per 5-7 square miles; be completed prior to Migration Survey May 19, 2009 minimum point separation distance construction 2 miles September 11- Methods follow spring raptor 13, 2009; Second year of study to Fall Raptor migration survey with the addition of October 2-4, be completed prior to Migration Survey 6 reference points outside of the 2009; October construction site. 25-27
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Survey Dates Description Comments BGEPA & MBTA 10-minute point count surveys conducted from dawn to 11am at 25 Second year of study to Spring Migratory May 19-20, 24- locations; count density of 1 point be completed prior to Passerine Survey 25, 2009 per 1-2 square miles distributed to construction represent habitat types; points separated by a minimum of 250m. 10-minute point counts conducted from dawn to 11am at 25 locations; Second year of study to Breeding Bird June 8 & 11, count density 1 point per 1-2 square be completed prior to Survey 2009 miles, distributed to represent construction. habitat types; points separated by a minimum of 250m. August 29 & 30, Methods follow spring migratory Second year of study to Fall Migratory 2009; September passerine survey with the addition be completed prior to Passerine Survey 11-13, 2009; of 25 reference points outside of the construction. October2-4, 2009 site, and three survey periods. December 15, Driving survey of passable roads on 2009; January Second year of study to site and reference area; all birds Winter Bird Survey 12, 2010; be completed prior to seen or heard recorded and February 23, construction. mapped. 2010 WGFD Regulations & Recommendations Driving surveys at first light on site April 11 & 16, Second year of study to Sage Grouse Lek in sagebrush habitat, particularly 2009 and May 7, be completed prior to Surveys near known lek locations; stops 2009. construction. every half mile. Bat Habitat Assessment of likely habitat use by
Analysis bat species. Results and detailed 1 met tower with a stationary methods to be reported in monitoring unit at 55m, and 8 Bat Acoustic June-October report addendum. Second locations at ground level monitored Monitoring 2010 year of study to be for 3 weeks each during the growing completed prior to season. construction. Evaluate site use by SGCN species SGCN analysis with particular attention to and Amphibian amphibians and reptiles including and Reptile Habitat mapping of potential habitat for Analysis these species Amphibian and All incidental observations of June-October, Results to be reported in Reptile Incidental amphibians and reptiles to be 2010 report addendum Observations reported. Mapping to assess whether or not Priority Watershed site is located within a priority Analysis watershed Use aerial photo analysis combined White-tailed Prairie with field verification to identify Dog concentration June 2010 areas of high-, medium- and low- mapping density White-tailed Prairie Dog populations. Wheatland Monitor activity and flight patterns Results to be reported in Reservoir June-July 2010 near Wheatland No. 3 Reservoir report addendum Observations
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2.2. Habitat Cover Mapping & Point Selection A habitat cover map was created to define, visualize and predict the locations where different wildlife communities were present (Map Exhibit 2). Base data were obtained from the NRCS National Land Cover Database – NLCD 2001 (USGS 2007), which has a resolution of 30x30m. Each NLCD land cover type was assigned to an AES habitat cover type for use in field surveys (Table 2). The raster image was clipped to the site boundary, and areas were calculated for each habitat type. Field observations in 2009 confirmed that the land covers had not significantly changed from 2001 when the aerial survey was completed. Delineation of Upland shrub-scrub and Grassland communities was inaccurate; therefore these two categories were combined in our mapping analysis. The site was compared with WGFD priority watershed data to determine whether the site lay within the state’s designated priority watersheds.
Table 2. AES habitat cover type descriptions. AES Habitat Cover Type Description
Developed Residential, commercial, industrial, and other developed land, including developed green space (e.g., golf-course, city park).
Cropland Regularly cultivated land. Pasture, hay meadow, and fallow field are grasslands.
Barren Land Land with sparse to no vegetation (e.g., mines, landfills, construction sites, sparsely vegetated shores).
Grassland Grass and herbaceous plants cover ≥90% of the ground in uplands.
Upland Shrub-Scrub Shrubs and scrubby or mature trees cover 10-50% of the ground. Includes brush land and savanna with trees and shrubs.
Upland Broadleaf Forest Trees cover ≥50% of the ground. Broadleaf deciduous trees are ≥90% of the tree cover.
Upland Coniferous Forest Trees cover ≥50% of the ground. Coniferous (needle-leaved) trees are ≥90% of the tree cover.
Upland Mixed Forest Trees cover ≥50% of the ground. A mixture of broadleaf and coniferous trees, with each covering <90% of the forest.
Forested Wetland A wetland or lowland flooded area with 50-100% tree cover. Shrub-Scrub Wetland Wetlands with 10-50% cover by shrubs, scrubby and mature trees. Includes savanna with trees and shrubs. Emergent Wetland A wetland with ≥90% cover of herbaceous plants. Open Water Water and sparse to no vegetation cover; rivers, streams, lakes, ponds.
Sample points were selected and classified in the field on the basis of AES habitat cover types. Although mapping data did not accurately distinguish between Grassland and Upland-shrub scrub communities the distinction was clear in the field. Points were located in Grassland and Upland shrub-scrub habitats, and in Emergent wetland and Open water habitats along the site’s riparian corridors. These were the only habitats dominant enough in the landscape to warrant sampling. Due to the strong influence of water in this arid environment, all points with Open water or Emergent wetland at the sampling point were classified as Wetland points.
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Bird sample points were distributed to achieve a geographic representation of the site. Consequently, the dominant land use—Grassland—received a large number of sample points. Upland shrub-scrub and Wetland habitats were adequately sampled for statistical analysis (Table 3, Map Exhibit 2). Additionally, point selection was constrained to areas that could be accessed by passable roads, resulting in limited coverage in some areas. Reference points—used as a control for post-construction data comparisons—were selected off-site along publically accessible roadways in habitats similar to those on the site. The number of off-site reference points was approximately equal to the number of points inside the Boswell Springs wind farm. Because the first study season coincided with the release of the WGFD sampling protocols, reference points are missing for the spring and summer surveys. In the second season, reference points will be sampled in all survey periods.
Table 3. Habitat types, number of sampling points (P) and number of surveys (N) by survey type for the first study season. Passerine Raptor Breeding Passerine Fall - Raptor Fall - P(N) Spring - P(N) Spring - P(N) Bird - P(N) P(N) Habitat On On On Site On Site On Site Reference Reference Site Site Grassland 14 (14) 4 (12) 14 (14) 14 (42) 19 (57) 4 (24) 4 (24) Upland shrub- 6 (6) 1 (3) 6 (6) 6 (18) 6 (18) 1 (6) 2 (12) scrub Wetland 5 (5) 1 (3) 5 (5) 5 (15) 1(6) Total 25 (25) 6 (18) 25 (25) 25 (75) 25 (75) 6 (36) 6 (36)
2.3. Endangered and Threatened Species A request for information was made to the Wyoming Natural Diversity Database (WYNDD) regarding biological issues of concern at the proposed site in 2009. WYNDD responded with e- mailed GIS and summary data on February 20, 2009 (WYNDD 2009). These features of concern were evaluated from the standpoint of potential impacts from the wind farm. 2.4. Bald and Golden Eagles The WYNDD query (WYNDD 2009) was used to identify if there were any existing records of nesting eagles within 5 miles of the site. Eagles and eagle nests were also searched for during spring and fall migration and during an aerial nest search. See below for detailed methods. 2.5. Native and Sensitive Bird Species Impacts to native bird species are of greater concern than to non-native bird species, such as European Starling and House Sparrow which have no legal protection. Impacts to bird species in decline due to existing environmental factors are of particular interest in wind farm impact studies. AES terms these already at-risk birds “sensitive species.” Sensitive species are most likely to experience cumulative impacts from wind energy development due to existing factors unrelated to wind energy development. In its monitoring and analyses, AES biologists use native species as a broad indicator of wind farm impacts and sensitive species as a specific indictor of effects to species at risk from historical or ongoing habitat loss and other impacts. Sensitive species are similar to the species of concern as defined in the USFWS recommendations; however the AES-defined sensitive species emphasize the conservation significance of a species. For
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example, Mourning Dove is protected by the MBTA and some state game laws, but its population is large and at low risk from wind energy development. Consequently, it is a “species of concern” to the USFWS, but not a “sensitive species” in our analysis. Sensitive species vary from ecological region to ecological region, based on the abundance and population trends of species. Bird species at the site were identified as sensitive if they met one of the following conditions: • Endangered, threatened, candidate or special concern on federal lists; • Wyoming Species of Greatest Conservation Need (SGCN) • Birds of Conservation Concern for Region 10, Northern Rockies – U.S. portion only (USFWS 2008a), • Critically endangered, endangered, vulnerable, near threatened in IUCN Red Book; • Known from literature to require large habitat blocks (area-sensitive species); • Significantly declining in USGS Breeding Bird Survey (BBS) data (Sauer et al. 2008); or • Demonstrated to be significantly adversely affected by wind energy development. The BBS declining bird list was derived 1980-2007 bird trend data for ecoregions of the U.S. The site is located in the Wyoming Basin (BBS Region 86). All native birds in this region which were significantly declining and had a relative abundance of <5 birds per route were considered sensitive. A species seen <5 times on a 25-mile BBS route is an uncommon species; those with >5 per BBS route were common; e.g., Red-winged Blackbird, American Robin, Horned Lark. The significance of a decline depended on the quality of the data—number of routes on which a bird was sighted, number of times it was sighted and number of years it was sighted. BBS presents trend significance with a 3-tiered Regional Credibility Measure. For the BBS declining bird analysis a trend was considered significant if the variance in the decline due to sampling error was less than the decline measured in the field. The least credible trends required a decline >5 percent annually to be significant; the moderately credible trends required a decline >3% to be considered significant; and the most credible trends were considered significant regardless of the level of decline. Additionally, we included native birds that were significantly declining in USFWS Region 6 but not significantly increasing in the Wyoming Basin and which had a relative abundance <5 birds per route in the Wyoming Basin. Long-distance migrants are species of birds whose summer breeding grounds and wintering areas are completely separated geographically. They migrate at night. Typically these species breed in North America and winter in Central or South America. Many long-distance migrants are sensitive species, and there is concern about the impacts of wind development on them. Passerine birds account for three-quarters of bird fatalities at wind farms, and half of all passerines killed at wind farms are thought to be nocturnal migrants (Erickson et al. 2001; CEIWEP 2007).
2.5.1. Field Methods In 2009, 179 point count surveys were conducted at the site, and an additional 111 point count surveys were conducted in a reference area near the site. A BACI (Before-After Control-Impact) approach was used after the first season’s breeding bird survey. All second year surveys will be conducting using a BACI approach, with the reference point counts serving as the control. Point- count surveys were conducted during the spring and fall migratory periods and the breeding bird season. An aerial search by fixed-wing aircraft identified raptor nest locations, and raptor nest monitoring gathered data on flight paths. A winter bird survey documented winter bird use on the site. Incidental observations of bird activity were recorded at the Wheatland Reservoir to detect elevated bird use in that vicinity, if it existed, and spillover effects in the adjacent Boswell Springs site. Results of the raptor nest monitoring and the Wheatland Reservoir observations will be reported in an addendum to this report.
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For the fall migration and winter bird surveys, and the raptor nest search, reference areas were located off site in order to provide control data for surveys conducted after turbine construction. These reference areas were in habitats similar to those present on site and are not expected to be impacted by wind development. Reference points were along publicly accessible roads near the wind farm site. We did not sample wetland habitats in the reference areas due to a lack of wetland habitat in the surrounding landscape. However, we adequately sampled the dominant habitats at the Boswell Springs wind farm—Grassland and Upland shrub-scrub—to enable post-construction data comparison at locations where turbines are likely to be located.
2.5.1.1. Spring and Fall Passerine Migration and Breeding Bird Surveys Point count passerine surveys assessed bird community abundance and species richness during the 2009 spring migration, breeding bird and fall migration seasons (Table 4). Passerine birds were surveyed once during the spring migration, once during the breeding season, and at three different time periods during the fall migration. Twenty-five points were located in three habitat types and geographically distributed across the site (Map Exhibit 2, Table 3). An additional twenty-five points were located in the reference area in similar habitats. Points were at a minimum 250 meters apart. This resulted in an overall point density of 1 point per 1-2 square miles.
Table 4. Dates of bird surveys at Boswell Springs. Passerine Bird Raptor Spring Fall Spring Fall Aerial Nest Migration Breeding Migration Winter Migration Migration Search 5/19-5/20, 6/8 & 8/29 & 12/15/2009 4/10- 9/11- 4/26/2010 5/24-5/25/2009 6/11/2009 8/30/2009 4/11/2009 9/13/2009 9/11- 1/12/2010 4/16/2009 10/2- 9/13/2009 10/4/2009 10/2- 2/23/2010 5/19/2009 10/25- 10/4/2009 10/27/2009
Point counts lasted for 10 minutes. Data recorded were: all birds seen and heard in an unlimited radius of the sampling point, number of individuals, behavior, distance and direction from the observer, weather conditions, flight origin direction, flight direction, and flight height. Estimates of flight heights were based on comparison with known heights of existing objects (e.g. power poles, towers, trees). Survey data were entered into an Access database for storage and analysis. Survey times varied with season. In the spring passerine migration surveys began around dawn and lasted until 11am or until a noticeable drop in bird activity. In the breeding season surveys were conducted from around dawn to 10am, or until a noticeable drop in bird activity occurred. The fall passerine migration took place from dawn to dusk. Point counts were not performed in steady rain, with poor visibility, or in steady, strong winds.
2.5.1.2. Spring and Fall Raptor Migration Surveys Raptor surveys were conducted at three different times in both spring and fall migratory periods, with one count conducted during each survey round in the spring and two in the fall (Table 4). Six point count locations with distant, unobstructed views were placed in Grassland or Upland shrub- scrub habitat within the site (Map Exhibit 2, Table 3). An additional six point count locations were placed in similar habitat areas in the reference area. Points were at least 2 miles apart, with a resulting point density of one point per every 5-7 square miles. Raptor point counts lasted 30 minutes. Data collection followed the passerine survey methods above. Raptor surveys were conducted between 9am and 4pm on days when weather was favorable for raptor migration.
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2.5.1.3. Raptor Nest Search & Raptor Nest Monitoring An aerial survey from a fixed wing aircraft flown by France Aviation was conducted on April 26, 2010. The site and a reference area were surveyed on half-minute transects at an elevation of 200 feet. To avoid disturbance, nests were not circled; even if nest status was uncertain. Locations of all raptor activity and confirmed and possible nests were recorded as GPS points. Where feasible, nests were field verified from the ground. Snow made passage difficult. Nests were classed as confirmed nests or possible nests. Confirmed nests were clearly nests. Possible nests were structures that may have been nests but which could not be absolutely confirmed as nests. The confirmed nests were classed as occupied or unoccupied, and the species using the nest identified where known. Unoccupied nests were nests that did not show occupancy at the time of the survey. These nests may have been occupied at other times during the season due to late nesting attempts or could be occupied in future years. Occupied nests, where access was possible, were monitored from the ground to establish information on flight paths. Golden Eagle and Red-tailed Hawk nests known to exist south of the site were not accessible by public roads and therefore were not monitored.
2.5.1.4. Winter Bird Survey A winter bird survey was conducted by driving passable roads within the site and reference area on one day per month in December 2009 and January and February, 2010 (Table 4). The survey route was driven twice on each day. The GPS locations of bird activity were mapped, and the species, abundance, flight behavior, and habitat recorded. The December survey covered 9.9 miles on site, and 14.4 miles within the reference area. The January and February surveys covered the same route as the December survey; however, 5.4 mile of the reference route along a two-track gas line access road that was no longer accessible due to snow, resulting in 4.5 miles surveyed on site, and 14.4 miles surveyed in the reference area.
2.5.1.5. Sage Grouse Lek Survey Surveys for Sage Grouse were conducted on April 11, April 16 and May 7, 2009. Surveys were conducted by driving roads within the survey area, particularly the southern and eastern boundaries where previous sage-grouse sightings had been reported on the Wyoming Natural Diversity Database (WYNDD 2009). The site’s northwest corner was also surveyed because it supported the best sagebrush habitat in the area. Stops were made approximately every half-mile in sagebrush habitat to listen for sounds of grouse. Known historical lek sites on or within two miles of the site were specifically checked (Table5). Surveys were conducted from first light to one hour after sunrise.
Table 5. Historical sage-grouse leks located on or near the Boswell Springs Wind Farm.
Zone & Distance from Lek Name Easting Northing 2008 Status Site Fetterman 21 13T 439100mE 4636200mN Abandoned/Unoccupied 0.78 mi southeast Fetterman 22 13T 437101mE 4639491mN Abandoned/Unoccupied On site Cordingly 13T 426000mE 4641800mN Unoccupied On site Rock Creek Bend 13T 426700mE 4632000mN Unoccupied 3.5 miles south
2.5.2. Data Analysis Data were analyzed to determine the species present in different habitats and the richness and abundance of native, sensitive and long-distance migrant bird species across habitats. Exploration of the data indicated that the aggregate abundance by habitat was consistent across seasons and therefore data from all survey periods were combined for analysis. The effect of habitat on native and sensitive bird richness and abundance was tested for normality, and then a Kruskal-Wallis ranked ANOVA was completed, with pair wise comparisons using the Kolmogorov-Smirnov method. All
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points that had a Wetland or Open Water component were combined and classified as Wetland points. Wetlands surveyed at the site were exclusively in stream drainages. Although NLCD habitat mapping was inaccurate, differences observed in the field between Grassland and Upland shrub- scrub were notable and they were treated as separate habitats in the analysis. As a way to evaluate the utility of the reference points as a control, a Mann-Whitney rank sum test was performed to detect differences between Grassland and Upland shrub-scrub points on-site and in the reference area during the fall migratory period. There were no reference data available for the other seasons. For SGCN species and select sensitive species, the expected mortality rates were calculated based on existing mortality and abundance data from the Foote Creek Rim (FCR) facility (Young et al. 2003a and Johnson et al. 2000b) and abundance data from the spring passerine and breeding bird surveys at the Boswell Springs site. To determine expected mortality rate at FCR for a given species, we used mortality study turbine- carcass data to calculate the percentage of carcasses of that species out of all the carcasses. Then we used that percentage to calculate the proportion of the total mortality at FCR (1.5 BTY) due to that species. This calculation resulted in an expected mortality rate for that species at FCR. In order to determine the expected mortality rate at Boswell Springs the expected mortality rate from FCR needed to be adjusted for differences in abundance between the two sites. This was done by creating a ratio of the abundance at FCR (Johnson et al. 2000b) and the abundance at Boswell Springs to the expected mortality at FCR and the expected mortality at Boswell Springs. For species for which there were no individuals observed at the FCR facility, birds having similar flight behavior were used to approximate the expected mortality. For instance, the mortality rate of McCown’s Longspur, which was not observed at FCR, was estimated using the average mortality rate of three sparrows present at FCR because the longspur behaves like a sparrow rather than another type of bird, such as a warbler. The effect of the Wheatland Reservoir on nearby habitat was investigated. Three points in grassland habitat (3, 4, 5) located at 0.25-0.75 miles from the reservoir were compared to points in similar habitat farther away. A Mann-Whitney rank sum test was performed to detect differences in species richness and abundance between points near the reservoir and away from it. Data were from the fall passerine migration. Additional observations continue to be made to validate the preliminary findings reported here. 2.6. Bats and Collision Risk A desktop habitat analysis was conducted to assess the species of bats likely to be present on site in each habitat. Bats that use the general geographic area of the site were identified as those present in the site’s “latlong” in the Atlas of Birds, Mammals, Amphibians and Reptiles in Wyoming (Cerovski et al. 2004) or in several surrounding “latlongs”. The habitat requirements and range were assessed for each species, and those that were considered either “breeding possible” or “breeding unlikely” were assigned to the site habitats where they would be expected to occur. The habitat-based analysis used published descriptions of the species habitat requirements and ranges (Cerovski et al. 2004; Bat Conservation International 2009). For a “breeding possible” rating at a site, habitat was present, the site was in the species’ range, and the species was not rare. A rating of “breeding unlikely” meant the species had poor or marginal habitat at the site, was at the edge of its range, or was a rare species. Passive acoustic monitoring for bat activity is being conducted during the 2010 field season. One low monitoring unit is measuring bat activity for three weeks at each of 8 stations selected to represent potential bat habitat at the sites. The detailed methods and results of this survey will be reported in an addendum to this report.
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2.7. Species of Greatest Conservation Need Species of Greatest Conservation Need (SGCN) were identified in the Wyoming Wildlife Action Plan (WGFD 2005) as species requiring special consideration in the face of development, so as to prevent their decline. SGCN species observed on site included amphibians, small mammals and birds. AES consulted with WGFD to determine which of the SGCN species warranted additional study. In addition, the WGFD recommended a desktop habitat analysis for amphibians and reptiles, and the recording of incidental observations for all amphibians and reptiles at the site. To conduct the desktop habitat analysis, AES determined amphibians and reptiles likely to occur in the geographic region from the Atlas of Birds, Mammals, Amphibians and Reptiles in Wyoming (Cerovski et al. 2004). Those likely to occur on site were identified through a habitat-based analysis. The habitat-based analysis used published descriptions of the species habitat requirements and ranges (Cerovski et al. 2004, Nature Serve 2010). Species were considered likely to occur in the geographic region if there were atlas records for the site’s “latlong” or for several neighboring “latlongs”. From this initial list, species were classed as possibly breeding at the site, unlikely to breed at the site, or not present at the site. For “breeding possible,” the site must contain habitat for a species and be within a species’ range, and the species must not be rare. Species classed as “breeding unlikely” had poor or marginal habitat at the site, were at the edge of their range, or were rare. Species were then assigned to the habitats where they might occur on site. Species for which the site was out of range or which lacked appropriate habitat were not included.
2.7.1. White-tailed Prairie Dog White-tailed Prairie Dogs were generally present in grassland habitats on the site. Unlike Black-tailed Prairie Dogs they do not form dense colonies, but rather form dispersed colonies over larger areas. The White-tailed Prairie Dog is an SGCN species, and in addition is raptor prey. In order to determine if prairie dog activity might be influencing raptor presence, White-tailed Prairie Dog density was mapped using aerial photography, and mapping was verified by sampling transects in the field. Initial mapping was done by inspecting NAIP 2009 and BING Maps Web-service Imagery for the density of white dots associated with prairie dog burrows, and then mapping these locations as High, Medium and Low-to-No density areas. The minimum mapping unit was one-half square mile. Ground verification was conducted by sampling four transects in each category, High, Medium and Low-to-No density. Each transect was 100m long and all prairie dog burrows within 10m on either side of the transect were counted as a measure of density. A final map was produced of areas with different prairie dog densities. Prairie dog density was then compared to raptor abundance. 3. Results and Discussion 3.1. Habitat The Boswell Springs wind farm is predominately covered by Grassland and Upland shrub-scrub (sagebrush) habitat (Map Exhibit 2, Table 6). Sagebrush dominates the northwestern and northeastern portions of the property, while Grassland dominates the remaining areas. Seven-mile Creek and Spring Creek drain the center of the site, and Emergent Wetland and Open Water Wetlands are associated with these drainages. While some wetlands in these areas were mapped according to the NLCD classification as Forested wetlands, none of the wetlands on the site were actually forested. The Wheatland No. 3 Reservoir located to the southeast of the site is in a priority watershed as designated by WGFD (2009). This watershed covers a small area in the site’s southeastern corner (Map Exhibit 2)
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Table 6. Land Cover at proposed Boswell Springs site. Land Cover Acres Percent of Site Developed 106 0.49 Barren Land 8 0.03 Grassland and Upland Shrub-Scrub 21,145 97.62 Forested Wetland 119 0.55 Emergent Wetland 280 1.29 Open Water 4.2 0.02
3.2. Endangered and Threatened Species The State of Wyoming affords legal protection to animal and plant species that are listed under the Federal Endangered Species Act. A search of the Wyoming Natural Diversity Database (WYNDD 2009) revealed historic and unconfirmed records of the federally endangered Black-footed Ferret (Mustela nigripes) within 5 miles of the site. The federally threatened Canada Lynx (Lynx canadensis) and Greenback Cutthroat Trout (Oncorhynchus clarkia stomias) are also listed as potentially found near the site. However, the Lynx primarily uses subalpine habitat, and the Greenback Cutthroat Trout is thought to be extirpated from Wyoming. To our knowledge, there are no reports of large mammals, such as Lynx, being impacted by wind farm development. Fish are also unlikely to be impacted by the site so long as erosion is controlled during construction and soils are stabilized after construction. There is little standing water on the site, and fish are unlikely to persist in the site’s shallow stockponds or intermittent streams. The database also has records of the Mountain Plover (Charadrius montanus) along Fetterman Road within the site. The Mountain Plover recently was proposed for listing as a threatened species (USFWS 2010c).
3.2.1. Mountain Plover The Mountain Plover (Charadrius montanus), S2 (state imperiled) and G3 (globally vulnerable), was proposed for listing as a federally threatened species June 28, 2010 (USFWS 2010c). Recently populations have been stable, but historically the population contracted severely. Market hunting may have been one of the initial causes of population decline. Other causes include conversion of short-grass prairie to agricultural land, decline of prairie-dog towns which provided foraging and nesting habitat, and habitat loss in wintering areas (NatureServe 2010). The plover nests in high plains/short grass prairie and areas of short sagebrush. It is often associated with prairie dog towns (Wyoming Natural Diversity Database 2009). Construction, operation or maintenance activities at a wind farm project on the FCR Facility caused a severe reduction in nesting frequency and success of Mountain Plovers (Johnson et al. 2000b). The Biodiversity Alliance recommends avoiding all Mountain Plover nesting habitat (Molver 2008). There are 4 records of Mountain Plovers from several locations along Fetterman Road inside the site from 1991 and 1995. There are also 5 records from a nearby Breeding Bird Survey route from 1990 to 1999, and 14 other records within 5 miles of the site from 1983 to 1998. There are no database records at or near the site from the last ten years. No Mountain Plovers were found during the three survey periods conducted in the May 1 to June 15 period recommended by the USFWS (USFWS 2002). The surveyor was experienced in searching for Mountain Plover. However, the USFWS survey protocol was not used. It is possible that Mountain Plover were present but undetected at the site.
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3.2.2 Black-footed Ferret The Black-footed Ferret (Mustela nigripes) is state ranked S1 (critically imperiled) and critically imperiled globally as well. It is a federally endangered species. The species was extirpated across most of its range through prairie dog and predator control programs. A major obstacle to its re- introduction and recovery is the species’ susceptibility to sylvatic plague. The ferret is associated with prairie dog colonies in Grassland. White-tailed Prairie Dogs, one of the ferret’s prey species, are present throughout the site (Map Exhibit 5). Historic occurrences are reported by the Wyoming Natural Diversity Database (2009) from two vague historic 1960-era records for locations within 5 miles of the site. Habitat is present at the site, but no records of ferrets at the site exist. The Shirley Basin Black-footed Ferret Recovery Area boundary is located approximately 3 miles west of the site—although the release site is significantly to the northwest—and it is possible that the ferret could appear at the wind farm in the future. At this time Black-footed Ferret has not been seen at the site If the ferret should appear in the future, the effect of the wind farm project on the pattern of colonization and use of the site by ferrets cannot be known. 3.3. Bald and Golden Eagles Bald and Golden Eagles (Haliaeetus leucocephalus, Aquila chrysaetos) are protected by the BGEPA. The Wyoming Natural Diversity Database (WYNDD 2009) has records for both Bald and Golden Eagles on the site and within 5 miles of the site. Both Bald and Golden Eagles were sighted during the ground surveys. During the aerial surveys Golden Eagles were found nesting one and one-half miles southwest of the site in an aspen tree. One eagle was present at the nest. There were no signs of eggs. An additional Golden Eagle nest, unoccupied at the time of the survey, was found just northwest of the site (Map Exhibit 4). Bald Eagles were observed twice on the site during the fall migration at points 2 and 21 (Map Exhibit 1), and two birds were observed in the reference area during the aerial survey. Golden Eagles were observed 33 times on the site (5 during spring surveys, 1 during breeding bird survey, and 22 during fall surveys) and 23 times in the reference area (18 during the fall and 5 during the winter bird surveys (Map Exhibit 3)). The one sighting during the breeding season was at point 25 in the southern portion of the site within 5 miles of the known nesting location. During the spring and fall migrations Golden Eagle sightings were distributed across the site with no particular pattern to the observations. The distribution of eagle sightings did not correlate with abundance of White-tailed Prairie Dogs. Golden Eagles have a broad habitat association, utilizing open country that includes deserts, grasslands, savannas and woodlands. They nest on cliffs or ledges, or in large trees. Nesting habitat is available near Boswell Springs in stream drainages and areas of broken topography, and foraging habitat exists throughout the site. Golden Eagles experienced high mortality at the Altamont Wind Farm (Smallwood and Thelander 2008) where a thousand turbines were placed in densely populated hunting and migration areas. Since then, turbine design has changed dramatically, reducing the number of raptor kills. Taller towers put the rotor-swept area above usual hunting elevations. Solid tubular support towers do not provide the perching opportunities previously implicated in raptor mortality. Fewer and larger blades appear to be easier to see and do not have the “smear” associated with older turbine construction. In addition, wind farm developers are more aware of the importance of siting wind turbines away from raptor concentration associated with migration and foraging. For comparison, data on Golden Eagles from the FCR facility were used. FCR is located 25 miles southwest of the Boswell site in similar habitat. There were no Golden Eagles killed at the FCR I facility from 1998 to 2002 (Young et al. 2003a) despite a consistent presence of Golden Eagles at the site; however one Golden Eagle carcass was found at the FCR II and III facilities in a 1.5 year study
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(Young et al 2003b). At FCR, Golden Eagles had an abundance of 0.62 birds/survey in the spring, 0.48 birds/survey in summer, 0.70 birds/survey in fall, and 0.34 birds/survey in winter (Johnson 2000b). By comparison, Golden Eagles were present at Boswell with 0.22 birds/survey in the spring raptor surveys, 0.04 birds/survey in the breeding bird survey, and 0.44 birds/survey during fall raptor surveys. The density of Golden Eagles in migration and the breeding period is consistently lower than that at FCR. Considering the limited Golden Eagle mortality during four years of monitoring at the FCR facility (0.3 Golden Eagles per 100,000m2 RSA) (Young et al. 2003b) and the lower density at the Boswell site, the risk of collision is very low. Likewise, the limited use of the Boswell site by Bald Eagles suggests a very low collision risk for that species. Data from the second season of surveys will be used to validate this preliminary finding. 3.4. Native and Sensitive Bird Species The intent of AES’s general research on birds was to describe the distribution and abundance of native, sensitive and long-distance migrant bird species at different locations in the site so that decisions to use or avoid different areas could be made. AES observed 42 different species of birds on-site during the spring and fall migratory surveys (raptor and passerine) and the breeding bird survey (Appendix 2), and one species, Loggerhead Shrike, incidentally between survey points. During the fall migratory survey period 30 species were observed on site and 11 species were observed at the reference points (Appendix 3). One species observed in the reference area, American Coot, was not observed on site. All these species are considered native to the area and no non-native species were recorded. Of the 42 native bird species seen in point count surveys on the site, 18 (43%) were classified as sensitive species by criteria described above. Of these 18 sensitive species, 7 are experiencing declining abundance as indicated in Breeding Bird Survey data, and 9 species were derived primarily from lists of species of concern, including Wyoming Species of Greatest Conservation Need (WGFD 2005) and Birds of Conservation Concern (USFWS 2008a). The other two species, Northern Harrier and Vesper Sparrow, were classified as sensitive because they respond negatively to habitat fragmentation. The sensitive species list includes three BBS declining species which are otherwise common elsewhere in their range including: Barn Swallow, Mallard and Northern Shoveler. Loggerhead Shrike is also considered sensitive due to its presence on the Birds of Conservation Concern List, and American Coot (seen only in the reference area) is considered a sensitive species because it is declining in the region. Sensitive species have the greatest need for conservation action given their population status and trends and their habitat requirements. Because long-distance migrants are especially susceptible to collision risk, AES analyzed these species separately. Ten (23%) of the species observed were classified as long-distance migrant species. Native species, sensitive species and long-distance migrants are treated separately in the analysis below.
3.4.1. Collision Risk Death by collision is the most apparent risk to native and sensitive birds. Recent studies suggest that bird behavior is a stronger predictor of collision risk than other factors, such as observed flight height or local abundance (de Lucas et al. 2008, Smallwood et al. 2009). However, habitat is important in predicting the location of species. As a result, avoiding habitats supporting concentrations of native and sensitive bird species reduces collision risk for birds that are susceptible due to their behavior.
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3.4.1.1. Native Bird Species Collision Risk Temperatures were 30-84° F during the spring migration surveys, 38-53° F during the breeding bird survey, and 28-78° F during the fall migration surveys. The coldest temperatures were in late October and early November surveys. Sky conditions varied from clear to 100% cloud cover, and wind speeds varied from calm to over 12 mph. In general the data did not have a normal distribution in habitats. Consequently, statistical tests were used that handled non-normal data distributions, as described in the methods section above. In all seasons, Wetlands in riparian corridors had higher mean abundance and richness of native bird species than in Grasslands or Upland shrub-scrub habitat (Table 7). The difference in abundance and species richness was significantly different between the Wetland and either the Grassland or Upland shrub-scrub points. The higher richness and abundance of birds in Wetland habitats is due to a more complex habitat structure than Grassland or Upland shrub-scrub and to the presence of water in an arid environment. The Wetland habitat supports a group of species largely absent elsewhere at the site, particularly flocking ducks and shorebirds. In combination with grassland species entering the riparian zone survey points, this elevated the species richness of wetlands. The most common species across all survey periods, with over 40 individuals seen, were Horned Lark, Mallard, McCown’s Longspur, Blue-winged Teal, Green-winged Teal, Northern Shoveler, Gadwall, Western Meadowlark, Violet-green Swallow, and Vesper Sparrow (Appendix 2). These species comprised the majority (70%) of the individuals observed in surveys across the site. At the nearby Foote Creek Rim (FCR) facility overall mortality was estimated to be 1.5 BTY (birds/turbine/year) (Young et al. 2003a). This is slightly below studies in Pacific Northwest and Upper Midwest where a mortality rate of 1.98 and 2.22 BTY were measured (CIEWEP 2007). The FCR facility is situated in Grassland and Upland shrub-scrub habitat similar to that found at the site. The bird communities at the two sites are similar in general species composition. However bird diversity and richness at Boswell were higher than at FCR in the spring migration and breeding season. There were 6.51 birds/survey at FCR versus 12.7 birds/survey at Boswell, and 2.96 species/survey at FCR versus 4.7 species/survey at Boswell (Johnson et al. 2000b). Wetlands are limited in the FCR study area. Removing the wetland points from the Boswell data results in a mean abundance of 9.5 birds/survey and a mean richness of 3.7 species/survey, still higher than the FCR data. The most common species at FCR were Horned Lark, Vesper Sparrow, Brewer’s Sparrow, Cliff Swallow, Brewer’s Blackbird, Green-tailed Towhee, Pine Siskin, American Robin, American Goldfinch and Chipping Sparrow. The most common species at the Boswell Grassland and Upland shrub-scrub points were McCown’s Longspur, Horned Lark, Vesper Sparrow, Western Meadowlark, American Avocet, Brewer’s Sparrow, Lark Bunting, Killdeer, Brewer’s Blackbird and American Crow. McCown’s Longspur, American Avocet and American Crow were not present at the FCR facility. In summary, bird density and richness is 30-50% higher (excluding wetlands) at Boswell than at FCR, and some species were only found at Boswell, most notably McCown’s Longspur, which was common. However, the two sites are similar and near enough to each other so that expected mortality rates Boswell may be like those at FCR. As has been found at other wind farms (CIEWEP 2007), passerine birds comprise the majority of mortality at FCR. Overall mortality from both turbines and meteorological towers at FCR consisted of 92% passerine birds. About half of carcasses found (64 of 122) were considered migrants based on the dates of observation. The most common mortality occurred in Horned Lark, with 28 individuals found. Mortality at Boswell is predicted to be similar to that at FCR with mortality highest in species such as Horned Lark that are the most common and historically experience higher than average mortality at wind farms due to their flight behavior.
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Table 7. Native, sensitive, and long-distance migrant mean abundance and mean richness by habitat on-site during spring and fall passerine migration and breeding bird surveys1. Long-distance Native Species Sensitive Species Migrant Species On Site On Site On Site Mean Mean Mean Mean Mean Habitat (N) Abund. Mean Rich. Abund. Rich. Abund. Rich. Wetland (5) 41.88a 5.80c 13.80 2.04e 4.56g 1.32j Upland shrub-scrub (6) 5.17b 2.40d 1.73 1.07f 0.60h 0.27k k Grassland (14) 7.04b 2.10d 2.17 0.84f 1.50h 0.40 1Numbers in the same column with similar letters are statistically the same, and numbers with different letters are statistically different.
Surveys were completed in Grasslands during the fall migratory period simultaneously at the site and reference area. A comparison of these data at the site and reference area showed no statistically significant differences in mean abundance or richness for native and sensitive species or for long- distance migrants (Table 8). Consequently, use of the reference area as a control in the BACI approach will be valid. However, a second season of observations will be made to confirm this preliminary finding.
Table 8. Native, sensitive, and long-distance migrant mean abundance and mean richness on-site and in reference area during fall passerine migration surveys. Long-distance Migrant Native Species Sensitive Species Species Mean Mean Mean Location (N) Abund. Mean Rich. Abund. Mean Rich. Abund. Mean Rich. On Site (20) 16.33 3.00 1.67 1.33 1.33 0.33 Reference (25) 29.33 2.33 1.33 1.33 1.33 0.67
The investigation of the effect of the Wheatland Reservoir on the bird community during the fall migration revealed nothing unusual. There was no significant difference in the richness or abundance of birds between points at 0.25-0.75 miles from the Wheatland Reservoir and in similar habitat farther away. This suggests that the extensive water area at the Wheatland Reservoir does not significantly change the richness and abundance of the bird community in its vicinity. Rather certain species, such as waterfowl and shorebirds, may use the shoreline and open water of the reservoir, but not venture far beyond the reservoir’s edges. This finding will be validated with incidental observations being made periodically at the reservoir in the growing season of 2010, and reported in an addendum to this report.
3.4.1.2. Sensitive and Long-distance Migrant Bird Species Collision Risk Wetlands had a greater mean abundance and mean richness of sensitive bird species and long- distance migrants than Grassland and Upland shrub-scrub (Table 7). These differences were significant for all measures except for abundance of sensitive species. Grassland and Upland shrub- scrub did not differ significantly in richness or abundance for either sensitive species or long-distance migrants. There were three to eight times as many individuals of sensitive birds and long-distance migrants in Wetlands than in Grasslands or Upland shrub-scrub. Wetland sensitive species (14) included (Appendix 2): Mallard, Blue-winged Teal, Northern Shoveler, Black Tern, American Avocet, Ferruginous Hawk, McCown’s Longspur, Vesper Sparrow, Golden Eagle, Brewer’s Sparrow, Northern Harrier, Barn Swallow, Redhead and Bald Eagle. Grassland contained twelve sensitive species: McCown’s Longspur, Vesper Sparrow, Golden Eagle, American
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Avocet, Northern Harrier, Ferruginous Hawk, Sage Sparrow, Brewer’s Sparrow, Lark Bunting, Barn Swallow, Bald Eagle and Say’s Phoebe. Upland shrub-scrub contained eleven sensitive species: McCown’s Longspur, Vesper Sparrow, Brewer’s Sparrow, Golden Eagle, Northern Harrier, Say’s Phoebe, Ferruginous Hawk, Sage Sparrow, Barn Swallow, Lark Bunting and Burrowing Owl. Long-distance migrant species were not particularly common at the site, and were most common at Wetland points. Nine species occurred in Wetland habitats (Black Tern, Wilson’s Phalarope, American Avocet, Horned Grebe, Willet, Cliff Swallow, McCown’s Longspur, Barn Swallow and California Gull), four in Grassland habitat (McCown’s Longpur, American Avocet, Barn Swallow, and Rough-legged Hawk), and three in Upland shrub-scrub habitat (McCown’s Longspur, Barn Swallow and California Gull). Collision risk to sensitive species may be greater in Wetlands than in Grasslands or Upland shrub- scrub due the greater abundance of sensitive species in those habitats. Many of the sensitive species in the Wetlands were ducks and shorebirds that were confined to these habitats, and frequently present in large flocks. Other species such as Ferruginous Hawk, Brewer’s Sparrow, McCown’s Longspur, Vesper Sparrow, Northern Harrier, Barn Swallow and Golden Eagle were present across all habitats. AES researchers also observed that species associated with Wetlands usually did not occur much beyond the edge of those habitats. Thus the risk of collision in Wetlands may be affected by how close turbines are placed to Wetlands. Whether waterfowl move between the Wheatland Reservoir and the site’s wetlands is not known; observational data are being recording in the growing season of 2010 and will be reported in an addendum to this report. Turbines are most likely to be placed in Grasslands and Upland shrub-scrub habitats at Boswell Springs. Collision risk to sensitive species and long-distance migrants in grassland is moderate given the moderate abundance of these species in point counts. The behavior of individual species affects the risk, however. For instance, although Vesper Sparrow was not observed during a four-year-study to fly in the rotor-swept area of turbines at Buffalo Ridge, Minnesota, Johnson et al. (2000a) reported that 2 of 55 fatalities there consisted of Vesper Sparrow. This is probably the result of display flights (Wells and Vickery 1994) that take the bird into the rotor swept area. Of sensitive species at Boswell Springs McCown’s Longspur, Lark Bunting and Vesper Sparrow have high abundance and a flight behavior that sometimes takes them into the rotor swept area while engaged in territorial displays. This may increase their risk of collision, although McCown’s Longspur display elevations occur primarily below the rotor swept area. Calculated expected mortality, based on values from Foote Creek Rim, for McCown’s Longspur is 0.44 BTY (CHECK); for Lark Bunting is 0.18 BTY; for Vesper Sparrow is 0.05 BTY. A second season of surveys will validate these preliminary findings.
3.4.1.3. Raptor Collision Risk Raptors were present at the site at low abundances throughout the year (Table 9). A total of 80 individual raptors were seen in the spring and fall migration surveys and in the breeding bird survey at the site during 47.8 hours of observations, for an average of 1.67 raptors per hour of observation. Golden Eagle, Ferruginous Hawk, Northern Harrier and Turkey Vulture were the most commonly observed raptors. Additionally, five Golden Eagle and four Rough-legged Hawks were seen during the winter bird survey in the reference areas near the site. No raptors were observed on site during the winter bird surveys. The nearest fall hawk watch location to the site is Commissary Ridge near Kemmerer in southwest Wyoming (Hawk Migration Association of North America 2010a). Commissary Ridge is approximately 300 miles west of Boswell Springs. In 2009 there were 532 hours of observations from August 27-November 5 at Commissary Ridge, during which 2,840 raptors were observed (5.34 raptors/hour). On survey dates at Commissary Ridge that corresponded to survey dates at Boswell Springs, there were 206 raptors observed in 78.5 hours (2.62 raptors/hour). Dominant birds at Commissary Ridge, with over 100 individuals per species, were Red-tailed Hawk, Sharp-shinned Hawk, Cooper’s Hawk, Golden Eagle, Swainson’s Hawk and American Kestrel. Fourteen other
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species had fewer than 100 birds over the count period. By comparison, in the fall migration there were 2.0 raptors/hour at Boswell Springs, and no Red-tailed Hawk, Sharp-shinned, Cooper’s or Swainson’s Hawks. The nearest spring hawk watch location is Dinosaur Ridge, near Denver, Colorado (Hawk Migration Association of North American 2010b). Dinosaur Ridge is approximately 200 miles south of Boswell Springs. Spring 2009 surveys were conducted in April and May and 592 raptors were observed in 81.75 hours of observations (7.24 raptors/hour). Dates of observations at the hawk watch site did not correspond with dates of observations at Boswell Springs. The dominant species were Red-tailed Hawk, Cooper’s Hawk, Turkey Vulture and American Kestrel. During spring migration at Boswell Springs, 1.06 raptors/hour were observed and no Cooper’s Hawks were seen. In summary, the passage of raptors at Boswell Springs in spring was similar in composition to that at Dinosaur Ridge, but over the entire survey period was one-seventh to one-third the overall rate of passage at Dinosaur Ridge and Commissary Ridge respectively. For those days in the fall when surveys occurred at both Commissary Ridge and Boswell Springs, the raptor count was similar (2.62 versus 2.0 raptors/hour). It appears that in general Boswell Springs is not a significant concentration area during spring and fall raptor migration, but on some days in the fall the rate of raptor passage may be elevated as a broad front of raptors passes through in synchrony with the passage of weather fronts across the region. This preliminary finding will be validated in the second season of surveys.
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Table 9. Raptor abundance by survey. Spring Migration Breeding Bird Fall Migration Total Abundance Common Abundance (13.17 Abundance (4.17 Abundance (30.5 (47.84 hours Name hours observation) hours observation) hours observation) observation) American 1 0 1 2 Kestrel
Bald Eagle 0 0 2 2
Burrowing 0 0 1 1 Owl Ferruginous 2 2 14 18 Hawk Golden 5 1 22 28 Eagle Northern 2 2 13 17 Harrier Prairie 0 0 1 1 Falcon Red-tailed 1 0 0 1 Hawk Rough- 1 0 0 1 legged Hawk Turkey 0 0 7 7 Vulture Unidentified 2 0 0 2 Raptor
Total 14 (1.06 raptors/hr) 5 (1.20 raptors/hr) 61 (2.00 raptors/hr) 80 (1.67 raptors/hr)
The aerial raptor nest survey at Boswell Springs in April, 2010 found two nests on site that are probably Red-tailed Hawk nests (Map Exhibit 4, points 38 & 43): one unoccupied nest on a ledge, possibly a Ferruginous Hawk nest (point 46), and a possible nest on a structure (point 36). In the reference area there were nests and possible nests of Golden Eagle, Ferruginous Hawk, Red- tailed Hawk and Swainson’s Hawk. The occupied Golden Eagle nest is 1.5 miles southwest of the site (point 6). There was a mature Golden Eagle perched next to the nest at the time of the aerial survey. No eggs were present in the nest. There was a second nest in a nearby aspen that was unoccupied at the time of the survey. The third eagle nest, also unoccupied at the time of the survey, is located just northwest of the site (point 7). The two occupied Ferruginous Hawk nests (points 109 & 35) are located north of the site. A female was incubating eggs at the time of the survey at point 35, and the male was nearby. There were four Ferruginous Hawk nests that showed no signs of occupancy at the time of the survey (points 25, 33, 21, 30), and one structure that may have been a Ferruginous Hawk nest at point 31. There was an occupied Red-tailed Hawk nest south of the site (point 9 – one adult on nest and one nearby) and two additional Red-tailed Hawk nests (points 17 and 15) whose occupancy could not be determined due to poor visibility. Lastly there was an occupied Swainson’s Hawk nest 7.5 miles southwest of the site. During the 6 hours of aerial survey time a total of 23 individual raptors were observed. On site there were two Ferruginous Hawks, one Northern Harrier and one Red-tailed Hawk. To the north of the site there were six sightings: one mature Golden Eagle, one juvenile Golden Eagle, one Cooper’s
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Hawk and the three Ferruginous Hawks associated with occupied nests. South of the site there were 13 raptor sightings: two Bald Eagles, two juvenile Golden Eagles, one mature Golden Eagle at the occupied nest, another mature Golden Eagle, two Northern Harriers, three Red-tailed Hawks and two Swainson’s Hawks. The highest concentration of raptors was seen along the Rock River valley southwest of the site. The other raptor sightings were scattered across the reference areas and the site. By several indications, raptor nesting activity is less at Boswell than in the reference area, probably due to available locations for nesting. This preliminary finding will be evaluated during a second season of surveys. Boswell Springs is not a likely concentration area for raptors during the fall or spring migration period, but is visited by two species of particular concern to the USFWS, Golden Eagle and Ferruginous Hawk. It is important, however, to recall that when wind farms are not located at raptor concentration areas, such as ridgelines and passes, raptor fatality rates have been documented to be much lower than for passerine birds and other groups (Johnson et al. 2000a; CIEWEP 2007). For example, only five raptor deaths were recorded in four years of monitoring at the FCR facility (0.03 BTY - 3 American Kestrels, 1 Northern Harrier, 1 Short-eared Owl) (Young et al. 2003a). No Golden Eagles or Ferruginous Hawks were killed, despite their presence at the FCR. Mortality rates should be similar at Boswell Springs due to the visibility afforded to raptors by flat terrain and distant unobstructed views.
3.4.2. Habitat Displacement Risk Bird species most at risk of habitat displacement are sensitive to the size of habitat patches or to intrusions into their habitat by human activities and infrastructure. Prior studies to detect habitat effects caused by wind turbines have focused on grassland, steppe and shrubland birds since these seem more sensitive to habitat displacement than forest or wetland birds and appear to be experiencing greater declines as a group in North America than forest birds (Leddy et al. 1999; Herkert et al. 2003; CIEWEP 2007; Mabey and Paul 2007). Certain grassland bird species appear to have lower nesting densities in the vicinity of wind turbines; e.g., Savannah Sparrow (Leddy et al. 1999; Johnson et al. 2000). While prairie grouse species are not known to be displaced by wind turbines, their avoidance of other areas disturbed by humans suggests they may respond negatively to wind farm development (Manville 2004; CIEWEP 2007). Possible mechanisms for avoidance behavior include the perception by grassland birds that turbines are vertical structures, like trees, and are to be avoided, and the visual disturbance of moving blades. Others have documented displacement of grassland birds due to traffic noise (e.g., Forman et al. 2003), but it is not known if a noise level from a wind turbine is perceived by birds to be similar to the same noise level from traffic. AES uses sensitive species as an indicator of displacement risk because it includes species that are already rare and should be protected, those that are area sensitive and at risk due to additional habitat fragmentation, and those that are known to be adversely affected by wind turbines. Habitats that contain more individuals of sensitive species may be at greater risk of habitat displacement than those with few. A few species at Boswell Springs are considered sensitive to habitat displacement. In the breeding season the potentially area-sensitive Vesper Sparrow (Dechant et al. 2000) was present in Grassland (8 of 14 points) and Upland shrub-scrub (3 of 6 points), but rare in Wetland (1 of 5 points). The area-sensitive Northern Harrier (Johnson and Igl 2001) was rare overall, present at a single Grassland and Wetland point in the breeding season. Neither Vesper Sparrow nor Northern Harrier are declining in the BBS region nor are they SGCN species. Of the SGCN species area sensitivity has not been studied for McCown’s Longspur (Dechant et al. 1999b), which is abundant at the site, but the rarer Lark Bunting may be area-sensitive (Dechant et al. 1999a). Brewer’s Sparrow is common at the site but is not known to be area sensitive and appears able to find and use small Upland shrub-
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scrub patches with sagebrush (Vasquez 2005). See section 3.6 below for a discussion of risk to these species. In summary, habitat displacement may occur in Grasslands and Upland shrub-scrub due to the response of grassland birds to tall structures, noise or human disturbance. The placement of turbines in Grassland and Upland shrub-scrub at the site may result in a shifting of territory location or a reduction in nesting density in Vesper Sparrow, which is not an SGCN species nor declining in the region. What is less clear is whether displacement will occur in McCown’s Longspur, which is abundant at the site but has not been studied for area-sensitivity. Declines in this species may largely be due to management practices, rather than habitat fragmentation (Dechant et al. 1999b). These preliminary findings will be studied in the second season of surveys.
3.4.2.1. Sage Grouse Displacement Risk No signs of Sage Grouse were observed in the 2009 grouse surveys. Historical lek locations were unoccupied at the time of the surveys. The site lies outside the designated Sage Grouse Core Areas. Since there is no evidence of Sage Grouse using the site at this time, impacts to Sage Grouse are unlikely. However, the presence in the area of Sage Grouse in the past and of good sagebrush habitat currently raises the possibility that Sage Grouse will use the area in the future. This possibility will be investigated by conducting a second year of Sage Grouse monitoring prior to the construction of the wind farm. 3.5. Bat Habitat Based Risk Analysis Of eighteen bat species in Wyoming, three possibly occur at the site and five are unlikely to occur at the site (Table 10). The range or the habitat for the other six species is absent at Boswell Springs. The dominant habitat mapped at the sites is Grassland and Upland shrub-scrub. Species most likely to be found in these habitats are Big Brown Bat, Fringed Myotis and Western Small-footed Myotis. As discussed, passive acoustic monitoring is occurring at the site and a report of findings will be produced at the end of 2010.
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Table 10. Bat habitat-based risk analysis. Habitat % Site Species Possible at Site Species Unlikely at Site Qualifying Land Factors for Cover Unlikely at Site Common Name Scientific Name Common Name Scientific Name Grassland & 97.61% Big Brown Bat Eptesicus fuscus Townsend's Big-eared Bat Corynorhinus townsendii Requires mine & Upland cave roosts Shrub/Scrub Fringed Myotis Myotis thysanodes Pallid bat Antrozous pallidus Rare statewide Western Small-footed Myotis Myotis ciliolabrum Emergent 1.29% Big Brown Bat Eptesicus fuscus Little Brown Myotis Myotis lucifugus Mostly forest-using Wetland Forested 0.55% Big Brown Bat Eptesicus fuscus Hoary Bat Lasiurus cinereus Mostly forest-using Wetland Little Brown Myotis Myotis lucifugus Mostly forest-using Silver-haired Bat Lasionycteris noctivagans Mostly forest-using Developed 0.49% Big Brown Bat Eptesicus fuscus Little Brown Myotis Myotis lucifugus Mostly forest-using Open Water 0.02% Big Brown Bat Eptesicus fuscus Hoary Bat Lasiurus cinereus Mostly forest-using Fringed Myotis Myotis thysanodes Little Brown Myotis Myotis lucifugus Mostly forest-using Western Small-footed Myotis Myotis ciliolabrum Pallid bat Antrozous pallidus Rare statewide Silver-haired Bat Lasionycteris noctivagans Mostly forest-using Bold Text indicates species known to be susceptible to collisions with wind turbines. Species Possible at Site = habitat at site, site is in range, and species is not rare Species Unlikely at Site = poor/marginal habitat, edge of range, or rare species
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3.6. Species of Greatest Conservation Need Nine bird Species of Greatest Conservation Need (SGCN) were observed on the site. While these species do not have a legal protected status, it is recommended that impacts be avoided or mitigated where possible. The SGCN species included: McCown’s Longspur (125 individuals at multiple points), Brewer’s Sparrow (16 individuals at multiple points), Ferruginous Hawk (18 individuals at multiple points), Lark Bunting (4 individuals at multiple points), Bald Eagle (2 individuals at 2 points in fall survey), Black Tern (35 individuals on 2 fall survey days at 1 point), Burrowing Owl (individual in the fall survey), Redhead (3 individuals at 1 point in spring survey) and Sage Sparrow (9 individuals at 3 points in spring survey). The McCown’s Longspur, Brewer’s Sparrow, Ferruginous Hawk and Lark Bunting were observed during the breeding season, and field observations indicate that these may potentially breed at Boswell Springs. The other species were observed in spring and fall migrations at a few sample points or in low numbers. Due to their rarity and ephemeral presence at the site, these species will not be considered further.
3.6.1. McCown’s Longspur In all surveys 125 individuals of McCown’s Longspur were recorded on site. Of these 73 (58%) were observed during the breeding season. Those observed during the breeding season included 59 individuals at twelve of fourteen Grassland points, 12 at three of six Upland shrub-scrub points, and two individuals at a Wetland point embedded in Grassland habitat. There is no clear geographic pattern to their distribution on the site. McCown’s Longspur breeds in short-grass prairie or heavily grazed mid-grass prairie and prefers grasslands with sparse litter cover. Sometimes it breeds in cultivated lands. It is unknown whether McCown’s Longpur is area sensitive as no studies have investigated the relationship between patch size and nest success (Dechant et al 1999b). McCown’s Longspur populations are increasing in the region, but decreasing survey-wide when data from the United States and Canada data are combined (Sauer et al. 2008). McCown’s Longspur is not present at the FCR facility (Johnson et al. 2000b) and published mortality data are not available for this species. Collision risk for the species is likely to be relatively low as typical flight heights are well below the RSA, including its well-known aerial flight display which typically reaches 10m into the air (With 1994). Since no McCown’s Longspurs were present at the FCR site, Brewer’s Sparrow and Chipping Sparrow mortality and abundance were used to calculate expected mortality. At FCR there were 2 Brewer’s Sparrow and 3 Chipping Sparrow carcasses found, or 6.0% of all mortality. The expected mortality adjusted for abundance (0.554 Chipping Sparrows & Brewer’s Sparrows per survey at FCR, 2.7 McCown’s Longspurs per survey at Boswell Springs) is 0.44 BTY. A second season of surveys will validate these preliminary findings.
3.6.2. Brewer’s Sparrow Brewer’s Sparrow was found at four of the six Upland shrub-scrub locations during the breeding season (points 6, 7, 12, 13, Map Exhibit 1). It was also found at point 19, a Wetland point surrounded by Upland shrub-scrub habitat. During the spring migration four individuals were seen: three at Grassland points and one at an Upland shrub-scrub point. During the fall migration four birds were found, two at point 19 and at one each at two Upland shrub-scrub points. In summary, Brewer’s Sparrow was common in Upland shrub-scrub habitat in the breeding season, and present during spring and fall migration. Brewer’s Sparrow requires sagebrush habitat for nesting (Walker 2004). In North America, the Brewer’s Sparrow chiefly occupies low (<3ft) shrub-scrub habitat, primarily sagebrush (Short 1984;
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Vasquez 2005). A typical nesting density is one nest per 0.5-2ha. In Colorado it is known to occupy sagebrush patches as small as 6ha (Vasquez 2005). While nesting was not confirmed at Boswell Springs, the presence of adult singing males suggests that breeding was attempted. The consistent presence of the species at most of the Upland shrub- scrub points indicates that it is probably present throughout the Upland shrub-scrub habitats at the site. Flight behavior of this species suggests that collision risk will be relatively low; however 2 individuals were presumed killed at turbines in the four-year monitoring study at the Foot Creek Rim facility (Young et al. 2003a). If we assume similar mortality to the FCR facility, mortality for this species would be 0.02 BTY (2.4% of the overall 1.5BTY mortality estimate; 0.448 Brewer’s Sparrows per survey at FCR and 0.25 Brewer’s Sparrows per survey at Boswell Springs). Displacement is not likely to occur as area sensitivity has not been demonstrated in this species (Vasquez 2005). A second season of surveys will validate these preliminary findings.
3.6.3. Ferruginous Hawk Ferruginous Hawk used the site in all seasons. In the breeding season, two Ferruginous Hawks were found at two points (10 and 14, Map Exhibit 1) in the north near the off-site occupied nests. In migration, 14 individuals were seen at six points in the fall (points 2, 3, 4, 5, 6, 15) and two at two points in the spring (15, 12). Two individuals were spotted during the aerial nest survey. In the reference area, 9 individuals were sighted in the fall migration at six points, and three individuals were sighted during the aerial nest survey, all near the occupied nests north of the site. Except for the tendency of the hawks to concentrate in the north of the site and in the reference area to the north, there is no clear geographic pattern to the other hawk sightings. Threats to Ferruginous Hawks include habitat loss, accidental poisoning, and human disturbance. It is particularly sensitive to disturbance during the nesting season with remote nests typically having greater nesting success (NatureServe 2009). They utilize open habitat including grasslands, shrub/scrub and desert areas. Common nesting locations include tall trees and willows along riparian corridors or on steep slopes, ledges, and river-cut banks. The hawk was observed at low density across the site in all seasons, though it appears concentrated in the breeding season toward the north of the site, perhaps in relationship to occupied nests located north of the site in the reference area. Wind turbines at the site are not likely to result in a high level of mortality, given low raptor mortality rates at FCR and other wind farm sites. No Ferruginous Hawks were reported in the FCR mortality data (Young et al. 2003a). Disturbance of nesting pairs may result from construction in the north part of the site during the critical nesting period. Habituation to wind turbines is known to occur in raptors, as the high raptor use of the Altamont facility has demonstrated. A second season of surveys will validate these preliminary findings.
3.6.4. Lark Bunting Lark Bunting was found at two points during the breeding bird survey (points 1 and 13, Map Exhibit 1). Three individuals were found at a Grassland point (1) and one at an Upland shrub-scrub point (13). Nesting was not confirmed for this species, but its presence in breeding habitat during the breeding season suggests that breeding was attempted on site. The species was not observed on site during migration. Lark Buntings breed in the short-grass prairie region of North America, and typically prefer short grass areas often with a bare soil and shrub component. They may be area sensitive as they are not typically found in small isolated grassland patches, but no studies have directly examined the relationship between patch size and nesting success (Dechant et al 1999a). They are declining in the region and nationally (Sauer et al 2008). One Lark Bunting was killed in four years of observation at the FCR facility (Young et al. 2003a). The mortality rate for Lark Bunting is not known from other post-construction studies. If we
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assume similar mortality to the FCR facility we would expect a mortality of 0.18 BTY (1.2% of the overall 1.5 BTY mortality estimate; 0.01 Lark Buntings per survey at FCR and 0.1 Lark Bunting per survey at Boswell Springs). Despite an aerial display that causes this bird to climb to a height of 10m (Shane 2000), its flight behavior is much like other sparrow-like birds, with associated low mortality rates. The low density of this species at Boswell Springs and its generally non-risky flight behavior suggest that collision mortality will likely be low, although its displacement response to turbines is unknown. A second season of surveys will validate these preliminary findings.
3.6.5. White-tailed Prairie Dogs White-tailed Prairie Dogs (Cynomys leucurus) were located in Grasslands throughout the site. Inspection of the aerial imagery for sign of prairie dog presence resulted in a map of population density (Map Exhibit 5). Prairie Dogs were densest in Grassland areas and least dense in Upland shrub-scrub habitats and along riparian corridors.
Field verification of the remote-sensed map showed the map to be generally accurate. Transects in areas mapped with high density prairie dog burrows had a mean count of 17.4 burrows per transect. Those mapped as medium density had a mean count of 8 burrows per transect, and those mapped as low-to-none had a mean count of 3.5 burrows per transect. The difference was significant between high density areas and both medium and low-to-none areas. The difference was insignificant between medium density areas and low-to-none areas.
High density prairie dog areas will experience the greatest impact from wind turbine construction, and low-to-none areas the least. Prairie dogs likely will habituate to the presence of wind turbines, but a small percentage of available habitats may be lost to turbine pads and roads.
3.6.6. Amphibians and Reptiles Twenty species of amphibians and reptiles were identified as likely to occur in the general area of the site. American Bullfrog, Boreal Toad, Northern Leopard Frog, Woodhouse’s Toad, Wyoming Toad, Eastern Yellow-bellied Racer, Plains Hog-nosed Snake, Red-lipped Plateau Lizard, Northern Sagebrush Lizard, Western Painted Turtle and Western Spiny Softshell were considered out of range or lacking habitat at the site. Many of these required elevations below 6,000 feet, well below the 7,310-8,524ft elevation of the site. The remaining species were rated as “breeding possible” or “breeding likely” and assigned to habitats on the site (Table 11). Only one species, the Boreal Chorus Frog, was confirmed to be present on the site. Incidental observations of reptiles and amphibians are being made in spring and summer 2010 and will be reported in an addendum to this report. Amphibian and reptile species that use the Upland shrub-scrub and Grassland habitats are most likely to be impacted by the wind farm development because these habitats may contain most of the turbines and associated development. Although no individuals have been observed on site, breeding in these habitats is possible for Bullsnake, Greater Short-horned Lizard and Prairie Rattlesnake.
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Table 11. Amphibian and reptile habitat-based risk analysis. % Site Breeding Possible Breeding Unlikely Qualifying Factors for Breeding Land Unlikely Habitat Cover Common Name Scientific Name Common Name Scientific Name Grassland Pituophis Intermountain and Upland 97.61% Bullsnake Thamnophis elegans vagrans Water very limited on site catenifer sayi Wandering Gartersnake Shrub/Scrub Uncommon, specimens outside of Ornate Box Turtle Terrapene ornata ornata Goshen county probably released Greater Short- Phrynosoma Lampropeltis triangulum Pale Milksnake Typically below 6000 feet horned Lizard hernandesi multistriata Cnemidophorus sexlineatus Uncommon, prefers sandy loose Prairie Racerunner viridis soil Crotalus viridis Prairie Rattlesnake Tiger Salamander Ambystoma tigrinum Water very limited on site viridis Emergent Boreal Chorus Pseudacris Intermountain 1.29% Thamnophis elegans vagrans Water very limited on site Wetland Frog* maculata Wandering Gartersnake Pituophis Cnemidophorus sexlineatus Uncommon, prefers sandy loose Bullsnake Prairie Racerunner catenifer sayi viridis soil Tiger Salamander Ambystoma tigrinum Water very limited on site Forested Boreal Chorus Pseudacris Intermountain 0.55% Thamnophis elegans vagrans Water very limited on site Wetland Frog* maculata Wandering Gartersnake Tiger Salamander Ambystoma tigrinum Water very limited on site Pituophis Intermountain Developed 0.49% Bullsnake Thamnophis elegans vagrans Water very limited on site catenifer sayi Wandering Gartersnake Tiger Salamander Ambystoma tigrinum Water very limited on site Boreal Chorus Pseudacris Intermountain Open Water 0.02% Thamnophis elegans vagrans Water very limited on site Frog* maculata Wandering Gartersnake Pituophis Cnemidophorus sexlineatus Uncommon, prefers sandy loose Bullsnake Prairie Racerunner catenifer sayi viridis soil Tiger Salamander Ambystoma tigrinum Water very limited on site Species Possible at Site = habitat at site, site is in range, and species is not rare Species Unlikely at Site = poor/marginal habitat, edge of range, or rare species * Species confirmed on site
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4. Summary of Effects and Recommendations to Reduce Impacts Best management practices are recommended by the Wyoming Game and Fish Department (2010), U.S. Fish and Wildlife Service Wind Turbine Guidelines Advisory Committee (2010b) and the U.S. Fish and Wildlife Service Ecological Services (2010a) (Appendix 4, 5, 6). In addition to these recommendations, site-specific recommendations derived from the 2009-2010 surveys are provided below. A second season of surveys will be completed prior to construction of the wind farm and these recommendations may be consequently revised. 4.1. Endangered and Threatened Species There are no rare features that require special consideration at the site. However, the Mountain Plover has just been proposed for listing as a federally threatened species. Historic records exist for Mountain Plover on the site along Fetterman Road, and Mountain Plover habitat is present at the site. No Mountain Plovers have been observed at the site during any surveys conducted to date. Mountain Plovers are not always observed using point counts and casual observations even during the May 1-June 15 optimal survey period, and therefore may be present on the site despite current lack of evidence. • Coordinate need for Mountain Plover surveys with USFWS and WGFD and carry out, if warranted. 4.2. Bald and Golden Eagles A few Bald Eagles were observed on the site in migration. No evidence was found that Bald Eagles nested on or near the site. An occupied Golden Eagle nest and a second unoccupied nest were located one and one-half miles southwest of the site, and an unoccupied nest was just northeast of the site. Golden Eagles were observed at the site in the spring, breeding and fall surveys and in the reference area during the winter surveys. • Discuss the occurrence and management of Golden Eagle with USFWS and WGFD. • Avoid disturbing nests during the critical nesting period by following the eagle management guidelines during construction. 4.3. Native and Sensitive Bird Species Collision risk and the risk of displacement from habitat would affect sensitive bird species more than other native bird species because such species already are experiencing problems that make them a focus of conservation. For this reason, sensitive bird species are of the greatest interest in risk assessment. Of the 53 native bird species documented in point count surveys in the West Arc area, 23 are classified as sensitive. This number is higher than expected due to bird species which are declining in the region but are common elsewhere (e.g., Mallard, Barn Swallow, Blue Jay).
4.3.1. Native, Sensitive and Long-distance Migrant Bird Species Collision Risk Analysis of point count data identified significant differences in the number of native and sensitive species by habitat. Grassland and Upland shrub-scrub habitat had fewer native, sensitive and long- distance migrant species than did Wetlands. Since collision risk is related to local abundance, with behavior an important additional factor, Grassland and Upland shrub-scrub habitat pose a lower risk to native and sensitive bird species compared to wetland habitats at the site. Raptors were present in low numbers at the site throughout the year. There is no significant raptor concentration at the site during the spring or fall migration period. Due to the low abundance of raptors at the site their collision risk is expected to be low.
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 28
• Avoid placing turbines in wetland habitats (Map Exhibit 6). • Place turbines 100m from riparian corridors and wetlands larger than 5 acres. • Place turbines 1600m from active raptor nests; no active nests were detected on-site or within 1600m of the site boundary in the first survey season. • Conduct post-construction mortality survey and document number of fatalities of grassland and shrub-scrub bird species. Mortality is predicted to be highest in species that are commonest and historically experience higher than average mortality at wind farms (e.g., Horned Lark).
4.3.2 Habitat Displacement Risk Some grassland bird species (e.g., Savannah Sparrow) appear to avoid wind turbines, reducing their nesting density and affecting the local population. Vesper Sparrows and Northern Harriers are also considered area sensitive and may be impacted by wind development. Lark Bunting and McCown’s Longspur may also be area sensitive. Vesper Sparrows and McCown’s Longspurs were found at many Grassland and Upland shrub-scrub locations. Neither of these species is declining in the BBS region, but McCown’s Longspur is listed as an SGCN species. • Conduct post-construction point count surveys to document density of Vesper Sparrow and McCown’s Longspur in grassland and shrub-scrub habitats, using the BACI approach. 4.4 Bats and Collision Risk The three bat species most likely to be found in the Grassland and Upland shrub-scrub habitat where the turbines will primarily be placed are Big Brown Bat, Fringed Myotis and Western Small-footed Myotis. None of these species are known to be particularly sensitive to wind development based on mortality data from existing wind farms. Additional information on bat species composition and relative abundance will be available as an addendum to this report when the first season of bat acoustic monitoring is completed in October 2010. There is, however, a generally poor understanding of the relationship between monitored bat abundance and bat mortality. • Conduct a one year post-construction mortality study for bats. • Monitor development of bat mortality mitigation strategies and implement if feasible. 4.5 Species of Greatest Conservation Need Nine SGCN bird species were observed at the site. Of these McCown’s Longspur, Brewer’s Sparrow, Ferruginous Hawk and Lark Bunting are likely to breed at the site. McCown’s Longspur is common throughout the site with 125 individuals sighted during all surveys. Amphibian and reptile species that are most likely to use the Grassland and Upland shrub-scrub habitats are Bullsnake, Greater Short-horned Lizard, and Prairie Rattlesnake. None of these species has been observed on the site to date. Boreal Chorus Frogs have been observed on site. White-tailed Prairie Dogs are present on site with greatest concentrations in Grassland habitats. • Discuss McCown’s Longspur, Brewer’s Sparrow, Ferruginous Hawk, Lark Bunting and White-tailed Prairie Dog with WGFD.
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 29
5. Literature Cited Bat Conservation International. 2009. Species and profiles. http://www.batcon.org/index.php/education/article-and-information/species-profiles.html (Accessed 2009). Cerovski, A.O., M. Grenier, B. Oakleaf, L. Van Fleet, and S. Patla. 2004. Atlas of Birds, Mammals, Amphibians, and Reptiles in Wyoming. Wyoming Game and Fish Department Nongame Program, Lander. Chapman, S.S., S.A. Bryce, J.M. Omernik, D.G. Despain, J. ZumBerge and M. Conrad. 2004. Ecoregions of Wyoming (color poster with map, descriptive text, summary tables, and photographs). U.S. Geological Survey (map scale 1:1,400,000), Reston, Virginia. Accessed http://www.epa.gov/wed/pages/ecoregions/wy_eco.htm#Ecoregions%20denote, 4/20/2009. CEIWEP (Committee on Environmental Impacts of Wind-Energy Projects). 2007. Environmental impacts of wind-energy projects, Chapter 3. National Research Council, National Academies Press, Washington DC. Dechant, J.A., M.L. Sondreal, D.H. Johnson, L.D. Igl, C.M. Goldade, A.L. Zimmerman and B.R. Euliss. 1999a (revised 2002). Effects of management practices on grassland birds: Lark Bunting. Northern Prairie Wildlife Research Center, Jamestown, ND. Dechant, J.A., M.L. Sondreal, D.H. Johnson, L.D. Igl, C.M. Goldade, P.A. Rabie and B.R. Euliss. 1999b (revised 2002). Effects of management practices on grassland birds: McCown’s Longspur. Northern Prairie Wildlife Research Center, Jamestown, ND. Dechant, J.A., M.F. Dinkins, D.H. Johnson, L.D. Igl, C.M. Goldade and B.R. Euliss. 2000 (revised 2002). Effects of management practices on grassland birds: Vesper Sparrow. Northern Prairie Wildlife Research Center, Jamestown, ND. de Lucas, M., G.F.E. Janss, D.P. Whitfield and M. Ferrer. 2008. Collision fatality of raptors in wind farms does not depend on raptor abundance. Journal of Applied Ecology 45:1695-1703. Erickson, W.P., G.D. Johnson, M.D. Strickland, D.P. Young, Jr., K.J. Sernka and R.E. Good. 2001. Avian collisions with wind turbines: A summary of existing studies and comparisons to other sources of avian collision mortality in the United States. National Wind Coordinating Collaborative, Washington DC. http://www.nationalwind.org/pubs/default.htm. Forman, R.T., D. Sperling, J.A. Bissonette, A. P. Clevenger, C.D. Cutshall, V.H. Dale, L. Fahrig, R. France, C.R. Goldman, K. Heanue, J.A. Jones, F.J. Swanson, T. Turrentine and T.C. Winter. 2003. Road ecology: science and solutions. Island Press, Washington DC. Hawk Migration Association of North America. 2010a. Commissary Ridge raptor migration project. Jeff Smith and Mike Neal (lead contacts). Data provided by the Hawk Migration Association of North America (www.hmana.org) through its online HawkCount database (www.hawkcount.org). Accessed June 2010. Hawk Migration Association of North America. 2010b. Dinosaur Ridge Hawk Watch Site. Jeff Tim Smart and Jeff Birek (lead contacts). Data provided by the Hawk Migration Association of North America (www.hmana.org) through its online HawkCount database (www.hawkcount.org). Accessed June 2010. Herkert, J., D.L. Reinking, D.A. Wiedenfeld, M. Winter, J.L. Zimmerman, W.E. Jensen, E.J. Finck, R.R. Koford, D.H. Wolfe, S.K. Sherrod, M.A. Jenkins, J. Faaborg, & S.K. Robinson. 2003.
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 30
Effects of prairie fragmentation on the nest success of breeding birds in the midcontinental United States. Conservation Biology 17:587-594. Johnson, G.D, W.P. Erickson, M.D. Strickland, M.F. Shepherd and D.A. Shepherd. 2000a. Avian monitoring at the Buffalo Ridge, Minnesota Wind Resource Area: Results of a 4-year study. Western EcoSystems Technology, Inc., Cheyenne WY. Johnson, G.D. D.P. Young, W.P. Erickson, C.E. derby, M.D. Strickland, R.E. Good and J.W. Kern. 2000b. Final Report. Wildlife monitoring studies for the Seawest Windpower Project carbon County, Wyoming 1995-1999. Western EcoSystems Technology, Inc. Johnson, D.H., and L.D. Igl. 2001. Area requirements of grassland birds: a regional perspective. Auk 118(1):24-34. Jamestown, ND: Northern Prairie Wildlife Research Center Online. http://www.npwrc.usgs.gov/resource/birds/gbarea/index.htm (Accessed 2010). Leddy, K.L., K.F. Higgins and D.E. Naugle. 1999. Effects of wind turbines on upland nesting birds in Conservation Reserve Program grasslands. Wilson Bulletin 111:100-104. Mabey, S and E. Paul. 2007. Critical literature review: impact of wind energy and related human activities on grassland and shrub –steppe birds. Report to the National Wind Coordinating Collaborative by the Ornithological Council, Chevy Chase MD. NatureServe. 2010. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.0. NatureServe, Arlington, VA. http://www.natureserve.org/explorer (Accessed 2010). Sauer, J.R., J.E. Hines and J. Fallon. 2008. The North American breeding bird survey, results and analysis 1966 – 2007, Version 5.15.2008. USGS Wildlife Research Center, Laurel, MD. Shane, Thomas G. 2000. Lark Bunting (Calamospiza melanocorys), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/542 Short, H.L. 1984. Habitat suitability index models: Brewer's sparrow. U.S. Fish Wildlife Service Report FWS/OBS-82/10.83, Fort Collins CO. Smallwood K.S. and C. Thelander. 2008. Bird mortality in the Altamont Pass Wind Resource Area, California. Journal of Wildlife Management 72:215-223. Smallwood, K.S., L. Rugge and M.L. Morrison. 2009. Influence of behavior on bird mortality in wind energy developments. The Journal of Wildlife Management 73:1082-1098. USFWS (US Fish and Wildlife Service). 2002. Mountain Plover survey guidelines—Montana. USFWS Ecological Services, Billings MT. USFWS – Wind Turbine Guidelines Advisory Committee. 2003. Interim guidelines to avoid and minimize wildlife impacts from wind turbines. USFWS – Division of Migratory Bird Management. 2008a. Birds of conservation concern. Published at: http://library.fws.gov/Bird_Publications/BCC2008.pdf (Accessed 2009). USFWS – Wind Turbine Guidelines Advisory Committee – Legal Subcommittee. 2008b. Legal White Paper. Published at http://www.fws.gov/habitatconservation/windpower/Subcommittee/Legal/Reports/Wind _Turbine_Advisory_Committee_Legal_Subcommittee_White_Paper_(Final_As_Posted).pdf (Accessed 2009). USFWS. 2009. Eagle permits; take necessary to protect interests in particular localities; final rules. Federal Register. 50CRF Parts 13 and 22. USFWS - Ecological Services. 2010a. Wind energy development: best management practices for migratory birds. USFWS, Wyoming Ecological Services Field Office, Cheyenne WY.
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USFWS – Wind Turbine Guidelines Advisory Committee. 2010b. Preamble and Policy Recommendations. Published at http://www.fws.gov/habitatconservation/windpower/wind_turbine_advisory_committee.h tml (Accessed 2010). USFWS. 2010c. Endangered and threatened wildlife and plants; listing the mountain plover as threatened. Federal Register 75:124. USGS (U.S. Geological Survey). 2007. nlcd_wy_utm13.tif derived from the National Land Cover Database (NLCD 2001) (United States Geological Survey, 30-Meter Grid). USDA NRCS - National Cartography & Geospatial Center, Washington DC. Vasquez, M. 2005. Brewer’s Sparrow (Spizella breweri) species assessment. Unpublished report, US Forest Service (Grand Mesa, Uncompahgre, Gunnison National Forests), Gunnison CO. Walker, B. 2004. Effects of management practices on grassland birds: Brewer’s Sparrow. Northern Prairie Wildlife Research Center, Jamestown ND. http://www.npwrc.usgs.gov/resource/literatr/grasbird/brsp/brsp.htm (Accessed 2010). Wells, J.V. and P.D. Vickery. 1994. Extended flight songs of Vesper Sparrows. The Wilson Bulletin. 106:696-702. WGFD (Wyoming Game and Fish Department). 2005. A comprehensive wildlife conservation strategy for Wyoming. http://gf.state.wy.us/wildlife/compconvstrategy/# (Accessed 2009). WGFD (Wyoming Game and Fish Department). 2009. Laramie Region: Aquatic and Combined Crucial Priority Areas. Unpublished map. WGFD, GIS Unit, Cheyenne WY. http://gf.state.wy.us/habitat/portal/index.asp. WGFD (Wyoming Game and Fish Department). 2010. Wildlife protection recommendations for wind energy development in Wyoming. March 2010 (3/19/10) Draft. Cheyenne WY. With, K.A. 1994. McCown's Longspur (Calcarius mccownii), The Birds of North America Online (A. Poole, Ed.). Ithaca: Cornell Lab of Ornithology; Retrieved from the Birds of North America Online: http://bna.birds.cornell.edu/bna/species/096 Wyoming Natural Diversity Database (WYNDD). 2009. Data compilation for H. Kieweg, completed February 20, 2009. Unpublished report. Wyoming Natural Diversity Database, University of Wyoming, Laramie WY. Young, D.P., W.P. Erickson, R.E. Good, M.D. Strickland and G.D. Johnson. 2003a. Final report: avian and bat mortality associated with the initial phase of the Foote Creek Rim Windpower Project, Carbon County, Wyoming November 1998-June 2002. Western EcoSystems Technology, Inc. http://www.west-inc.com/reports/fcr_final_mortality.pdf (Accessed July 2010). Young, D.P., W.P. Erickson, M.D. Strickland, R.E. Good and K.J. Sernka. 2003b. Comparison of avian responses to UV-light-reflective paint on wind turbines. Western EcoSystems Technology, Inc. http://www.west-inc.com/reports/fcr_nrel.pdf (Accessed July 2010).
Assessment of Wind Energy and Wildlife Interactions at Boswell Springs Wind Farm 32
Map Exhibit 1. Site Location & Survey Points
Map Exhibit 2. Site Habitats
Map Exhibit 3. Winter Bird Locations
Map Exhibit 4. Raptor Nest Locations
Map Exhibit 5. Interpreted Prairie Dog Population Density
Map Exhibit 6. Sensitive Areas
APPENDIX 1. SITE REVIEW
APPENDIX 2. PER-POINT ABUNDANCE OF BIRDS SURVEYED DURING ALL POINT-COUNT SURVEYS ON SITE
Habitat Type Grassland Upland Emergent Total (N=115) Shrub/Scrub Wetland (N=179) Common Name Scientific Name (N=39) (N=25) Horned Lark Eremophila alpestris 2.84 2.31 10.36 3.78 Mallard Anas platyrhynchos 0.00 0.00 5.08 0.71 McCown's Longspur* Calcarius mccownii 0.88 0.41 0.16 0.68 Unidentified Duck Anatinae (gen, sp) 0.00 0.00 3.80 0.53 Blue-winged Teal Anas discors 0.00 0.00 3.56 0.50 Green-winged Teal Anas crecca 0.00 0.00 2.40 0.34 Northern Shoveler Anas clypeata 0.00 0.00 2.36 0.33 Gadwall Anas strepera 0.00 0.00 1.88 0.26 Western Meadowlark Sturnella neglecta 0.19 0.15 0.68 0.25 Violet-green Swallow Tachycineta thalassina 0.03 0.00 1.52 0.23 Vesper Sparrow Pooecetes gramineus 0.17 0.41 0.16 0.22 Northern Pintail Anas acuta 0.01 0.00 1.44 0.21 Black Tern* Chlidonias niger 0.00 0.00 1.40 0.20 Red-winged Blackbird Agelaius phoeniceus 0.00 0.00 1.36 0.19 Wilson's Phalarope* Phalaropus tricolor 0.00 0.00 1.36 0.19 American Avocet* Recurvirostra americana 0.11 0.00 0.80 0.18 Golden Eagle Aquila chrysaetos 0.16 0.15 0.16 0.16 Killdeer Charadrius vociferus 0.04 0.00 0.92 0.16 Canada Goose Branta canadensis 0.00 0.00 0.96 0.13 Unidentified Passerine 0.07 0.18 0.32 0.13 Brewer's Blackbird Euphagus cyanocephalus 0.11 0.03 0.32 0.12 Ferruginous Hawk Buteo regalis 0.07 0.08 0.28 0.10 American Wigeon Anas americana 0.02 0.00 0.64 0.10 Northern Harrier Circus cyaneus 0.09 0.10 0.12 0.09 Brewer's Sparrow Spizella breweri 0.03 0.23 0.16 0.09 American Crow Corvus brachyrhynchos 0.11 0.03 0.04 0.08 Sage Sparrow Amphispiza belli 0.05 0.08 0.00 0.05 Horned Grebe* Podiceps auritus 0.00 0.00 0.32 0.04 Turkey Vulture Cathartes aura 0.05 0.00 0.04 0.04 Unidentified Sparrow Emberizidae (gen, sp) 0.02 0.13 0.00 0.04 Unidentified Bird Aves (gen, sp) 0.02 0.00 0.16 0.03 Willet* Tringa semipalmata 0.00 0.00 0.24 0.03 Say's Phoebe Sayornis saya 0.01 0.10 0.00 0.03 Barn Swallow* Hirundo rustica 0.01 0.03 0.12 0.03 Cliff Swallow* Petrochelidon pyrrhonota 0.00 0.00 0.20 0.03 Lark Bunting Calamospiza 0.03 0.03 0.00 0.02 melanocorys California Gull* Larus californicus 0.00 0.03 0.08 0.02 Redhead Aythya americana 0.00 0.00 0.12 0.02 Unidentified Hawk Accipitridae (gen, sp) 0.02 0.00 0.00 0.01 Unidentified Raptor 0.02 0.00 0.00 0.01 Bald Eagle Haliaeetus leucocephalus 0.01 0.00 0.04 0.01 American Kestrel Falco sparverius 0.00 0.05 0.00 0.01 American Goldfinch Carduelis tristis 0.01 0.00 0.00 0.01
Habitat Type Grassland Upland Emergent Total (N=115) Shrub/Scrub Wetland (N=179) Common Name Scientific Name (N=39) (N=25) Prairie Falcon Falco mexicanus 0.01 0.00 0.00 0.01 Red-tailed Hawk Buteo jamaicensis 0.01 0.00 0.00 0.01 Rough-legged Hawk* Buteo lagopus 0.01 0.00 0.00 0.01 Burrowing Owl Athene cunicularia 0.00 0.03 0.00 0.01 Mountain Bluebird Sialia currucoides 0.00 0.00 0.04 0.01 Loggerhead Shrike# Lanius ludovicianus 0.00 0.00 0.00 0.00 Bolded species were classified by AES as sensitive at the site. * This species is a long-distance migrant. # Species seen outside of count time-period. Raptor abundance includes 30-minute point count data; typical point count is 10 minutes.
APPENDIX 3. PER-POINT ABUNDANCE OF BIRDS SURVEYED DURING FALL PASSERINE AND FALL RAPTOR SURVEYS
Habitat Type Grassland Grassland Upland Shrub- Upland Shrub- Emergent Total (N=111) Total (N=111) Total (N=222) (N=75) (N=81) scrub (N=24) scrub (N=30) Wetland (N=12) Common Name Scientific Name On-Site Reference On-Site Reference On-Site On-Site Reference All Points Horned Lark Eremophila alpestris 2.25 4.6765 1.67 0.90 19.33 3.97 3.65 3.81 Mallard Anas platyrhynchos 0.00 0.00 0.00 0.00 8.92 0.96 0.00 0.48 Unidentified Duck Anatinae (gen, sp) 0.00 0.00 0.00 0.00 7.92 0.86 0.00 0.43 Blue-winged Teal Anas discors 0.00 0.00 0.00 0.00 7.25 0.78 0.00 0.39 Green-winged Teal Anas crecca 0.00 0.00 0.00 0.00 4.58 0.50 0.00 0.25 American Crow Corvus brachyrhynchos 0.13 0.53 0.04 0.00 0.00 0.10 0.39 0.24 Northern Shoveler Anas clypeata 0.00 0.00 0.00 0.00 4.50 0.49 0.00 0.24 Gadwall Anas strepera 0.00 0.00 0.00 0.00 3.92 0.42 0.00 0.21 Golden Eagle Aquila chrysaetos 0.20 0.21 0.17 0.03 0.25 0.20 0.16 0.18 Unidentified Passerine 0.11 0.22 0.25 0.00 0.50 0.18 0.16 0.17 Black Tern* Chlidonias niger 0.00 0.00 0.00 0.00 2.92 0.32 0.00 0.16 Northern Harrier Circus cyaneus 0.12 0.15 0.13 0.03 0.08 0.12 0.12 0.12 Canada Goose Branta canadensis 0.00 0.00 0.00 0.00 2.00 0.22 0.00 0.11 Ferruginous Hawk Buteo regalis 0.09 0.10 0.04 0.03 0.50 0.13 0.08 0.10 Unidentified Sparrow Emberizidae (gen, sp) 0.03 0.15 0.21 0.07 0.00 0.06 0.13 0.09 Vesper Sparrow Pooecetes gramineus 0.01 0.15 0.08 0.00 0.25 0.05 0.11 0.08 Turkey Vulture Cathartes aura 0.08 0.12 0.00 0.00 0.08 0.06 0.09 0.08 American Wigeon Anas americana 0.00 0.00 0.00 0.00 0.83 0.09 0.00 0.05 McCown's Longspur* Calcarius mccownii 0.08 0.05 0.00 0.00 0.00 0.05 0.04 0.05 Violet-green Swallow Tachycineta thalassina 0.03 0.00 0.00 0.00 0.67 0.09 0.00 0.05 Northern Pintail Anas acuta 0.00 0.00 0.00 0.00 0.50 0.05 0.00 0.03 Brewer's Sparrow Spizella breweri 0.00 0.00 0.08 0.00 0.17 0.04 0.00 0.02 Killdeer Charadrius vociferus 0.00 0.00 0.00 0.00 0.33 0.04 0.00 0.02 Unidentified Bird Aves (gen, sp) 0.00 0.00 0.00 0.00 0.33 0.04 0.00 0.02 Western Meadowlark Sturnella neglecta 0.00 0.00 0.00 0.00 0.33 0.04 0.00 0.02 American Kestrel Falco sparverius 0.00 0.01 0.04 0.00 0.00 0.01 0.01 0.01 Bald Eagle Haliaeetus leucocephalus 0.01 0.00 0.00 0.00 0.08 0.02 0.00 0.01 Red-winged Blackbird Agelaius phoeniceus 0.00 0.00 0.00 0.00 0.17 0.02 0.00 0.01 Say's Phoebe Sayornis saya 0.01 0.00 0.04 0.00 0.00 0.02 0.00 0.01 Unidentified Hawk Accipitridae (gen, sp) 0.01 0.01 0.00 0.00 0.00 0.01 0.01 0.01 American Avocet* Recurvirostra americana 0.00 0.00 0.00 0.00 0.08 0.01 0.00 0.00 American Coot Fulica americana 0.00 0.01 0.00 0.00 0.00 0.00 0.01 0.00 Barn Swallow* Hirundo rustica 0.00 0.00 0.00 0.00 0.08 0.01 0.00 0.00 Brewer's Blackbird Euphagus cyanocephalus 0.01 0.00 0.00 0.00 0.00 0.01 0.00 0.00 Burrowing Owl Athene cunicularia 0.00 0.00 0.04 0.00 0.00 0.01 0.00 0.00 Prairie Falcon Falco mexicanus 0.01 0.00 0.00 0.00 0.00 0.01 0.00 0.00 Loggerhead Shrike Lanius ludovicianus 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Bolded species were classified by AES as sensitive at the site. * species indicate long-distance migrant species..
APPENDIX 4. WYOMING GAME AND FISH COMMISSION - WIND ENERGY DEVELOPMENT BEST MANAGEMENT PRACTICES (WGFD 2010)
1. Wind turbines should not be sited in sage-grouse core areas without clear demonstration from the project proponent that the activity will not cause a decline in sage-grouse populations. 2. Developers should use the statewide wind energy/wildlife conflict map (GIS shapefiles available at http://gf.state.wy.us/habitat/TerrestrialHome/WindDevelopment/index.asp) as one of the first steps in evaluating the suitability of leases and pre-development planning. 3. To the extent practicable, site wind turbines and ancillary project components within habitats/areas already affected by other forms of development (e.g., cropland, oil and gas fields, mine sites). 4. Developments proposed within 2 miles of WGFD wildlife habitat management areas should be coordinated with WGFD to avoid or minimize impacts to associated wildlife species and habitats. 5. Developments proposed within 2 miles of federal wildlife refuges should be coordinated with WGFD and USFWS to avoid or minimize impacts to associated wildlife species and habitats 6. Avoid placing turbines in documented locations of any species of wildlife, fish, or plants protected under the Federal Endangered Species Act. 7. Historically, WGFD has recommended a 2 mile buffer seasonal stipulation around sage- grouse leks in non-core habitat that prohibited construction activities within the buffer from March 15 to June 30. Based on the Governor’s Executive Order and core area strategy, that buffer is now waived. However, within 2 miles of the perimeter of a non-core lek, construction activities between March 15 and June 30 should not occur between 6 pm and 8 am. The WGFD recommends that developers monitor leks subject to the new recommendation to evaluate its effectiveness to reduce the impacts of wind development on sage-grouse. 8. Any construction/development activities within 2 miles of the perimeter of occupied sharp- tailed grouse leks should be suspended from April 1 – July 15. 9. Turbines and all related infrastructure (no surface occupancy) should occur outside a 0.25 mile distance from the perimeter of sage-grouse leks in non-core habitat. 10. Turbines and all related infrastructure (no surface occupancy) should occur outside a 0.25 mile distance from the perimeter of plains sharp-tailed grouse leks. 11. Turbines and all related infrastructure (no surface occupancy) should occur outside a 0.6 mile distance from the perimeter of Columbian sharp-tailed grouse leks. 12. Avoid siting wind energy facilities within crucial big game winter ranges. 13. Avoid siting wind energy facilities in big game parturition areas. 14. If siting within big game winter ranges cannot be avoided, suspend construction activities from November 15-April 30. 15. If siting within big game parturition areas cannot be avoided, suspend construction activities from May 1-June 15.
16. Avoid placing wind energy facilities in locations that bisect major big game migration corridors as determined by on the ground mapping. 17. To the extent practicable, roads and fences should not bisect or run immediately adjacent to any water feature potentially preventing wildlife from reaching adjacent habitat. 18. To the extent practicable, herptile habitats such as fallen trees, prairie dog colonies, and potential basking rocks should be left intact. 19. Employees should be instructed to follow posted speed limits; be aware of and avoid, to the extent possible, collisions with all wildlife including reptiles that may be basking on the road surface. 20. Avoid locating overhead power lines, within 0.6 miles of the perimeter of occupied sage- grouse leks within sage-grouse core habitats. 21. Avoid power line crossings of perennial streams, lakes, reservoirs, riparian corridors, and large (>5 acres) wetlands, where feasible. Where power lines must be constructed across these features, include effective marking devices following recommendations of the Avian Powerline Interaction Committee (APLIC, 1994 or current edition). 22. Where feasible, place power lines collecting electricity from turbines underground. Use recommendations of the APLIC (2006) for any required above-ground lines, transformers, or conductors. 23. When siting wind turbines within 2 miles of wetlands, riparian areas, lakes, reservoirs, and forested habitats collect adequate information to demonstrate that specific turbine locations will not result in significant levels of impacts to associated wildlife species and habitats. Determinations should be made on a project specific basis based upon site-specific data and information. 24. Use non-guyed non-lattice meteorological towers or attach bird diverters to guy wires on guyed met towers. 25. Determine appropriate set-backs from ridges, bluffs or other features to avoid or minimize impacts to bats, neotropical birds, migratory birds or raptors. Determinations should be made on a project specific basis based upon site-specific data and information. 26. Minimize construction of roads, fences and other ancillary facilities to reduce overall fragmentation; use bird diverters on fences at or within 0.25 miles of, use or upgrade existing roads rather than constructing new roads where possible, 27. If bird mortality due to collisions with fences is documented, or if collisions are likely to occur due to new fence placement, implement appropriate actions to mitigate impacts. 28. To reduce the potential for wildlife collisions, appropriate speed limits should be imposed and enforced on roads. 29. Close access and maintenance roads to public travel except preexisting roads on public lands. 30. Access for hunting should continue within wind leases on public lands and on private land with landowner permission. Wind developers should not require indemnification from landowners who are willing to provide public access for hunting and fishing or from sportsmen and sportswomen who utilize the property. 31. Adopt appropriate turbine design and siting standards to minimize bird and bat collisions (see U.S. Fish and Wildlife Service 2003: and USFWS Wind Turbine Guideline Advisory Committee Recommendations 2010).
32. While still providing for site-security and workplace safety, applicants should comply with the USFWS Wind Turbine Guideline Advisory Committee Recommendations (2010) regarding lighting where possible. 33. Applicants should consult with WGFD to determine the location of new fences and what types of fence design and construction are appropriate based on wildlife resources of the site. 34. At the completion of each project construction phase provide WGFD as-built maps of roads, turbine locations and ancillary project components in a GIS format. 35. Construction should be suspended within buffers and during the dates specified around raptor nests as provided in Appendix B and as updated by WGFC.
APPENDIX 5 . USFWS SITE DEVELOPMENT AND CONSTRUCTION BEST MANAGEMENT PRACTICES (USFWS – WIND TURBINE GUIDELINES ADVISORY COMMITTEE 2010b)
1. Minimize, to the extent practicable, the area disturbed by pre‐construction site monitoring and testing activities and installations.
2. Avoid locating wind energy facilities in areas identified as having a demonstrated and unmitigatable high risk to birds and bats.
3. Use available data from state and federal agencies, and other sources (which could include maps or databases), that show the location of sensitive resources and the results of Tier 2 and/or 3 studies to establish the layout of roads, power lines, fences and other infrastructure.
4. Use native species when seeding or planting during restoration.
5. To reduce avian collisions, place low and medium voltage connecting power lines associated with the wind energy development underground to the extent possible, unless burial of the lines is prohibitively expensive (e.g., where shallow bedrock exists) or where greater adverse impacts to biological resources would result: a. Overhead lines may be acceptable if sited away from high bird crossing locations, to the extent practicable, such as between roosting and feeding areas or between lakes, rivers, prairie grouse and sage grouse leks, and nesting habitats. To the extent practicable, the lines should be marked in accordance with Avian Power Line Interaction Committee (APLIC) collision guidelines. b. Overhead lines may be used when the lines parallel tree lines, employ bird flight diverters, or are otherwise screened so that collision risk is reduced. c. Above‐ground low and medium voltage lines, transformers and conductors should follow the 2006 or most recent APLIC “Suggested Practices for Avian Protection on Power Lines.”
6. Avoid guyed communication towers and permanent met towers at wind energy project sites. If guy wires are necessary, bird flight diverters or high visibility marking devices should be used.
7. Use construction and management practices to minimize activities that may attract prey and predators to the wind energy facility.
8. Employ only red, or dual red and white strobe, strobe-like, or flashing lights, not steady burning lights, to meet Federal Aviation Administration (FAA) requirements for visibility lighting of wind turbines, permanent met towers, and communication towers. Only a portion of the turbines within the wind project should be lighted, and all pilot warning lights should fire synchronously.
9. Keep lighting at both operation and maintenance facilities and substations located within half a mile of the turbines to the minimum required: a. Use lights with motion or heat sensors and switches to keep lights off when not required. b. Lights should be hooded downward and directed to minimize horizontal and skyward illumination.
c. Minimize use of high‐intensity lighting, steady‐burning, or bright lights such as sodium vapor, quartz, halogen, or other bright spotlights. 10. Establish non‐disturbance buffer zones to protect sensitive habitats or areas of high risk for species of concern identified in pre‐construction studies. Determine the extent of the buffer zone in consultation with USFWS and state, local and tribal wildlife biologists, and land management agencies (e.g., U.S. Bureau of Land Management (BLM) and U.S. Forest Service (USFS)), or other credible experts as appropriate. 11. Locate turbines to avoid separating bird and bat species of concern from their daily roosting, feeding, or nesting sites if documented that the turbines’ presence poses a risk to species. 12. Avoid impacts to hydrology and stream morphology, especially where federal or state‐listed aquatic or riparian species may be involved. 13. Although it is unclear whether tubular or lattice towers reduce risk of collision, when practical use tubular towers or best available technology to reduce ability of birds to perch and to reduce risk of collision. 14. Minimize the number and length of access roads; use existing roads when feasible.
15. Minimize impacts to wetlands and water resources by following all applicable provisions of the Clean Water Act (33 USC 1251‐1387) and the Rivers and Harbors Act (33 USC 301 et seq.); for instance by developing and implementing a storm water management plan and taking measures to reduce erosion.
16. Reduce vehicle collision risk to wildlife by instructing project personnel to drive at appropriate speeds, be alert for wildlife, and use additional caution in low visibility conditions.
17. Instruct employees, contractors, and site visitors to avoid harassing or disturbing wildlife, particularly during reproductive seasons.
18. Reduce fire hazard from vehicles and human activities (instruct employees to use spark arrestors on power equipment, ensure that no metal parts are dragging from vehicles, use caution with open flame, cigarettes, etc.)
19. Follow federal and state measures for handling toxic substances to minimize danger to water and wildlife resources from spills.
20. Reduce the introduction and spread of invasive species by following applicable local policies for noxious weed control, cleaning vehicles and equipment arriving from areas with known invasive species issues, using locally sourced topsoil, and monitoring for and rapidly removing noxious weeds at least annually.
21. Utilize pest and weed control measures as specified by county or state requirements, or by applicable federal agency requirements (such as Integrated Pest Management) when federal policies apply.
APPENDIX 6. WIND ENERGY DEVELOPMENT: BEST PRACTICES FOR MIGRATORY BIRDS (USFWS – ECOLOGICAL SERVICES 2010a) Impacts to migratory birds from wind energy development include collision mortality, displacement, and habitat fragmentation. These impacts can be reduced by management that: (1) avoids project construction in important bird habitats, (2) minimizes avian impacts from project construction and operation, (3) includes monitoring and reporting, (4) adapts to new information and conditions, and (5) provides mitigation.
Avoid Construction in Important Bird Habitats Impacts to migratory birds from wind energy development can be reduced by avoiding construction in areas important to bird species that are susceptible to collision mortality, displacement, and habitat fragmentation. In general, avoid locating wind energy facilities in areas that have unmitigatable high risks to birds, and consider the following steps: 1. Identify bird species that occur in the project area, are susceptible to displacement, collision mortality, and habitat fragmentation. Focus management on these species. From bird surveys, available data and literature identify bird species that occur in the area and identify behaviors that predispose birds to collision or displacement, such as flying at the altitude of the turbine blades or displaying behavioral avoidance of vertical structures. Bird species that winter in Wyoming, such as rough-legged hawks, as well as breeding and resident species, should be included in the analyses. 2. Identify important bird use areas for all seasons and seasonal migrations and avoid construction of wind turbines in those areas. The importance of an area to bird populations may be evaluated by measuring the frequency of bird occurrence, diversity of bird use, and proximity of other important bird habitats. Important bird use areas include breeding, nesting, foraging, sheltering (e.g., roost sites), seasonal migration routes, staging areas, and stopovers that are important in sustaining local and regional populations. Riparian zones, wetlands, rock outcrops, cliffs, isolated tree glades, and rodent colonies are high bird use areas for many species of birds in Wyoming, and development in those areas should be generally avoided. Pre-construction surveys should be used with previous studies and published literature to identify important bird areas and determine how they should be buffered from development. 3. Avoid bisecting flight zones between high bird use areas. Design preconstruction surveys to identify flight paths between important bird areas to avoid constructing powerlines and turbines in those flight paths.
Minimize Avian Impacts from Project Construction and Operation We recommend the following best management practices (BMPs) to reduce impacts to migratory birds: • Minimize the area disturbed during pre-construction activities such as monitoring and testing, as well as during the subsequent project actions. • Where feasible, locate wind projects on previously disturbed lands (that provide minimal wildlife habitat), and utilize existing transmission corridors and roads. • Design project layout to reduce likelihood of collision and electrocution: o Site turbines in groups rather than spreading them widely, and orient rows of turbines parallel to known bird migrations.
o Site structures away from high avian use areas and the flight zones between high use areas. o Dismantle nonoperational turbines and metrological towers. o Bury powerlines when feasible to reduce avian collision and electrocution. o Follow the Avian Power Line Interaction Committee (APLIC) guidance on power line construction (APLIC 2006) and power line siting (APLIC 1994). o Minimize the extent of the access road network. o Develop a transportation plan, including road design, locations and speed limits to minimize habitat fragmentation and wildlife collisions. • Select project features that minimize impacts to birds: o Use tubular (versus lattice) towers, or the best available technology, to reduce ability of birds to perch and to reduce risk of collision. o Avoid use of guy wires. If guy wires are necessary, mark them with bird flight diverters or other high visibility devices. • Keep lighting facilities and substations to the minimum required: o Use only red, or dual red and white strobe, strobe-like, or flashing lights, not steady burning lights, to meet FAA requirements for visibility lighting. o Minimize use of high-intensity lighting, or bright lights such as sodium vapor, quartz, halogen, or other bright spotlights. o Light only a portion of the turbines, and ensure that all pilot warning lights fire synchronously. o Install motion or heat sensors and switches to turn off lights when not required. o Hood and direct lights downward to minimize horizontal and skyward illumination. • Maintain facilities to minimize avian impacts: o Utilize pest control measures as specified by the county, state, or federal agencies. If project structures are attracting rodents, such as deer mice, identify and eliminate those practices. Do not control for native wildlife without contacting the appropriate regulatory agency. o Avoid management that indirectly results in attracting raptors to turbines, such as seeding forbs or maintaining structures that attract lagomorphs and rodents. o Move stored parts and equipment that may be utilized by small mammals for cover, away from wind turbines. o Wherever fossorial mammals burrow under tower pads, fill holes and surround pad with gravel at least 2 inches deep and out to a perimeter of at least 5 feet. o Immediately remove carcasses that have the potential to attract raptors, from roadways and from areas where raptors could collide with wind turbines. o Control for invasive plants by following local policies for weed control, clean vehicles and equipment arriving from areas with invasive species, use locally sourced topsoil, and monitor and rapidly remove noxious weeds. o Use native species when seeding or planting for restoration and maintenance. • Reduce vehicle collision risk to birds: o Instruct project personnel and visitors to drive at low speeds, and be alert for wildlife, especially in low visibility conditions. o Plow roads during winter so as not to impede ungulate movement. Snow banks can cause ungulates to run along roads resulting in vehicular collision. Roadside carcasses attract raptors, subjecting them to collision as well. o Reduce vehicle collision risk to raptors by removing carrion from roadsides.
• Follow procedures that reduce risk to avian populations: o Instruct employees, contractors, and visitors to avoid disturbing wildlife, especially during breeding seasons and periods of winter stress. o Reduce fire hazards from vehicles and human activities (e.g., use spark arrestors on power equipment, ensure no metal parts are dragging from vehicles, and use caution with open flames such as cigarettes). o Follow federal and state measures for handling toxic substances to minimize danger to water and avian habitats from spills. o Minimize impacts to wetlands and water resources by following all applicable provisions of the Clean Water Act (33 USC 1251-1387). • Form a Technical Advisory Committee to review post-construction monitoring and make recommendations for monitoring, adaptive management, or mitigation. We suggest the committee be comprised of representatives from the company and their wildlife consultant, and biologists from applicable agencies, that may include the Bureau of Land Management, the U.S Forest Service, Wyoming Game and Fish Department, and the Service.
Monitor and Report
Pre-construction Surveys Because migratory bird use of a site can vary between years, we recommend field surveys for a 3-year period prior to the start of project construction unless that period can be reduced due to sufficient, existing information about local bird populations.
Avian Activity Surveys Both point counts and transect surveys can be used to estimate bird use, and are assumed to be indices of abundance. Point counts should be used for surveys of raptors and other large birds. Surveys should collect vertical (flight height) as well as horizontal data to identify avian activity within the rotor-swept zone. Recommended methodology for avian point counts and line transect surveys are described by Reynolds et al. (1980), and Schaffer and Johnson (2008), respectively. Surveys that are distributed throughout the area using a probability sampling approach (e.g., systematic sample with a random start) allow for statistical extrapolation of data. Areas of special interest, including proposed wind turbine and meteorological tower sites, should also be surveyed. Alternatively, larger plots can be located at vantage points, throughout the proposed project area, with the objective of covering most of the area of interest. Sampling duration and frequency may vary on a project-by-project basis. The most important consideration for sampling frequency is the amount of variation expected among survey dates and locations and the species of concern. Relating avian use to site characteristics requires that surveys include measurements of site characteristics thought to influence use (i.e., covariates such as vegetation and topography). Sampling frequency should consider the episodic nature of activity, e.g., fall and spring migration. If more precise estimate of density is required for a particular species (e.g., to determine densities of a special-status species), more sophisticated sampling procedures, including estimates of detection probability, may be needed.
Raptor Nest Searches Raptor nest searches are recommended. These surveys provide information to predict risk to local breeding populations, to inform micro-siting decisions, and for developing appropriately sized non- disturbance buffer around nests.
Nocturnal Surveys If characteristics of the project site and surrounding areas pose a high risk of collision to night migrating songbirds and other nocturnally active species, additional surveys may be needed. For most of their flight, songbirds and other nocturnal migrants are above the reach of wind turbines, but they pass through the altitudinal range of wind turbines during ascents and descents and may also fly closer to the ground during inclement weather.
Greater Sage-grouse and Mountain Plover Some avian species such as the greater sage-grouse and mountain plover merit special survey efforts due to their susceptibility to displacement and habitat fragmentation. Specific survey efforts should be used to address these species and should be based on current Wyoming Game and Fish Department and/or Service guidance.
Post-Construction Fatality Surveys To evaluate avian impacts and provide an understanding of adaptive management opportunities, mortality needs to be monitored at a sufficient number of turbines selected systematically with a random start point. Data on variability of avian mortality among turbines from projects with similar conditions within the same region can be used as a basis for determining sample size (Morrison et al., 2008). If the project contains fewer than 10 turbines, we recommend all turbines be searched. Stratification among different habitat types, with a sufficient number of turbines being sampled in each stratum, is also recommended. We further recommend that search plot width be twice the turbine height. The interval between carcass searches depends on carcass removal rates. If the primary focus is on large raptors, then a longer search interval (e.g., 14-28 days) is sufficient. If the focus is on fatalities of small birds, then a shorter search interval will be necessary. Raw carcass counts recorded using different search intervals and under different carcass removal rates and searcher efficiency rates are not directly comparable, therefore, carcass counts must be adjusted by equations for estimating fatality. Since some fatalities may occur on a highly periodic basis, it is recommended that some turbines be searched most days so that episodic events are more likely to be detected, regardless of the search interval. It is recommended that all fatality studies conduct carcass removal and searcher efficiency trials using accepted methods (Anderson 1999, NRC 2007).
Fatality Reporting The purpose of reporting is to evaluate the effectiveness of pre-construction planning, elucidate adaptive management actions that can be taken to address unanticipated mortality, and design potential mitigation if impacts are unavoidable. Reporting should occur at least annually and more frequently upon the recommendation of the Technical Advisory Committee or if adaptive management is facilitated by more frequent reporting. Reports, at a minimum, should include the following: • Avian fatality by turbine location for the current year and compared to previous years; • Determination whether fatality rates indicate other species have risen to the level of species of concern; • Estimated mortality rates compared to predicted fatality rates; • Relationships of bird fatalities to site characteristics; • Comparisons of fatality rates with other wind energy developments in similar areas; • Composition of migrant versus resident species fatalities; and • Evaluation of fatalities to determine how management of operations could be adapted to minimize further mortality.
Annual reports serve as a platform to develop improved pre-construction guidance, to adjust project operations to further minimize mortalities, to direct mitigation actions, and, combined with annual reports from other sites, to evaluate cumulative impacts to avian populations. Report Individual Mortalities to Service Law Enforcement. We recommend the following information be collected: • Species identification, age (adult or immature), and gender, if possible; • Location of the mortality (e.g., GPS location, utility pole number); • Condition of the mortality (e.g., fresh kill, broken wing); • Band or tag number if applicable; and • Digital photo of the scene. Do not move the bird until the Service’s law enforcement officer has been contacted, as there may be specific guidance based on the situation. When a fatality is found, we recommend following these steps, after the preliminary information has been collected: (1) Contact FWS law enforcement agent in charge, (307 527-7604); (2) If he is unavailable, contact our Ecological Services Office (307 772-2374); and (3) Contact the Wyoming Game and Fish Department (307 777-4600) who may be able to provide you with a local point of contact (i.e., game warden). The Service has an on-line system for electric utilities to report bird electrocutions or collisions. We encourage electric utilities associated with wind energy facilities to utilize this system at https://birdreport.fws.gov/BirdReportHomePage.cfm.
Adapt Operation Management Adaptive management is a step-wise feed-back loop to solve management problems and involves: (1) Assessing the management problem; (2) Proposing management options to alleviate the problem; (3) Implementing the management option; (4) Monitoring changes in problem as a result of the altered management; (5) Evaluating if altered management had desired effect; and (6) Adjusting management accordingly. Management options need to be tailored to local conditions and specific issues, and a Technical Advisory Committee can help identify specific remedial actions such as: • Painting blades to reduce wind smear; • Placing bird flight diverters in critical locations; • Adjusting turbine cut in speeds; • Installing bird strike indicator sensor, such as microphones, accelerometers or fiber optic sensors, to identify circumstances of bird fatalities; • Feathering turbine blades; • Seasonal shut downs; • Turbine relocation or removal; • Removal of artificial habitats attracting birds; and • Limiting domestic livestock grazing. Adaptive management may be targeted at specific species or groups of species, for example, alleviating mortality of resident species that repeatedly occur at specific locations may be accomplished with bird flight diverters, whereas impacts to long distant migrants may be best addressed by feathering turbines at critical times or weather conditions.
Mitigate Mitigation may be considered in cases where projects, after application of adaptive management continues to: (1) Have significant impacts on local avian populations; (2) Contribute to cumulative impacts that significantly impact regional avian populations; and/or (3) Result in significant impact to a species of concern. Possible need to mitigate for loss of important habitat can be determined by evaluating the spatial configuration and quality of habitat prior to development, via aerial and remote imagery, and then calculating the remaining patches of intact habitat post construction. Remaining patches of intact habitat and edge and interior habitats can be evaluated to determine the amount or extent of habitat to be restored. Addressing the above listed considerations, and working with the Service, as new information about best management practices becomes available, exhibits project proponents’ willingness and intent to conserve species protected by the MBTA and/or BGEPA.
Literature Cited Anderson, R., M. Morrison, K. Sinclair, & D. Strickland. 1999. Studying Wind Energy/ Bird Interactions: A Guidance Document. Metrics and Methods for Determining or Monitoring Potential Impacts on Birds at Existing and Proposed Wind Energy Sites. Avian Subcom. & Nat. Wind Coor. Com. Dec. 1999. Wash., D.C. 84 pp. Avian Powerline Interaction Committee (APLIC) 1994. Mitigating Bird Collisions with Power Lines: The State of the Art in 1994. Edison Electric Institute. Wash. D.C. Avian Powerline Interaction Committee (APLIC) 2006. Suggested Practices for Raptor Protection on Power Lines: The State of the Art in 2006. Edison Electric Inst. Wash. D.C. National Research Council (NRC). 2007. Environmental Impacts of Wind-Energy Projects. National Academies Press. Washington, D.C. www.nap.edu. Morrison, M.L., W.M. Block, M.D. Strickland, B.A. Collier, & M.J. Peterson. 2008. Wildlife Study Design. Second Edition. Springer, New York, New York, USA. 358 pp. Reynolds R.T., J.M. & Scott, R.A. Nussbaum. 1980. A variable circular-plot method for estimating bird numbers. Condor. 82:309–313. Shaffer, J.A. & D.H. Johnson. 2008. Displacement Effects of Wind Developments on Grassland Birds in the Northern Great Plains. VII Wind &Wildlife. Research Meeting, Milwaukee, Wisconsin. Oct. 28-29, 2008.
APPLIED ECOLOGICAL SERVICES, INC.
21938 Mushtown, Road, Prior Lake MN 55372 Phone: (952)447-1919 Fax: (952)447-1920 Email: [email protected]
Bringing the science of ecology to all land use decisions
December 15, 2009
Paul Martin Intermountain Wind, LLC PO Box 353 Boulder, CO 80306
Subject: Boswell Springs Wind Energy Project – 2009 Progress Report
Dear Paul:
This year-end progress report summarizes the work that we have completed to date and provides a schedule for anticipated future work. It also provides some preliminary evaluation of issues of concern.
1. FIELD SURVEYS – COMPLETED & SCHEDULED The surveys listed below are suggested in “Recommendations for Wind Energy Development in Crucial and Important Wildlife Habitat” issued 10/30/2009 by the Wyoming Game and Fish Department (WYGFD).
Completed Surveys Prior to Post 2009 Scheduled 2010 Construction Construction Raptor Survey Apr-May 2009 1 season Sage-Grouse Survey Apr-May 2009 1 season Spring Migratory May 2009 1 season Passerine (Bird) Survey Breeding Bird Survey Jun 2009 1 season Fall Migratory Sep-Oct 2009 1 season Passerine (Bird) Survey Fall Raptor Migration Sep-Nov 2009 1 season Survey Winter Bird Survey Dec 2009-Feb 1 season 2010 Raptor Nest Survey Apr 2010 1 season Completed Surveys Prior to Post 2009 Scheduled 2010 Construction Construction Bat Acoustic Apr-Oct 2010* 1 season Monitoring (Passive) Bat Acoustic Possible 2 years Monitoring (Active) – to be determined in consultation with WYGFD Bat Mist Net Survey Possible 2 years – to be determined in consultation with WYGFD Bat Carcass Search 3 years – may be waived if most sensitive habitat is avoided Bird Carcass Search 3 years – may be waived if most sensitive habitat is avoided *Bat Acoustic Monitoring is anticipated pending discussion with WYGFD.
2. DATA ENTRY/ANALYSIS STATUS FOR COMPLETED SURVEYS Data Data Analysis Entered Scheduled For Raptor Survey Yes Jan-Feb 2010 Spring Migratory Passerine (Bird) Survey Yes Jan-Feb 2010 Breeding Bird Survey Yes Jan-Feb 2010 Fall Migratory Passerine (Bird) Survey Yes Jan-Feb 2010 Fall Raptor Migration Survey Yes Jan-Feb 2010
3. STATUS OF HABITAT MAPPING REQUIRED BY WYOMING GAME & FISH FOR PERMITTING Map Map Scheduled to Created be Created Site Habitats 2009 Mule Deer Winter Range 2009 Bats Habitat Risk Assessment Dec 2009-Jan 2010 Sage Grouse Habitat Dec 2009-Jan 2010 Amphibian & Reptile General Habitat Map (field mapping Dec 2009-Jan 2010 may be required after preliminary turbine siting is completed) Priority Watershed Dec 2009-Jan 2010
4. PRELIMINARY FINDINGS
4.1 Pre-Survey Site Review Black-footed Ferret – Protected as a federally endangered species. None were documented within the project boundary but may potentially occur due to the proximity of the Shirley Basin release site. Raptors – All raptors are protected by federal Migratory Bird Treaty Act (MBTA). Raptors are present on site during migration and breeding, however there are no known areas where raptors concentrate in high numbers during spring and fall migration (determined by review of existing data and literature). Generally, updraft zones on south and west facing slopes and ridgelines should be avoided. One year of required spring and fall raptor migration surveys have been completed. A second year of surveys will be completed prior to construction. A required nest search will be conducted in spring of 2010. Golden & Bald Eagles – Protected by federal Bald & Golden Eagle Protection Act. Several documented sightings within and near the project area. Recommended nest search to be carried out spring of 2010. Ferruginous Hawk – Several documented sightings inside and near the project area. Recommended nest search to be carried out spring of 2010. Waterfowl/Waterbirds – Protected by federal MBTA. Riparian wetlands and scattered emergent wetlands present and should be avoided with 100m buffer. Surveys during spring passerine migration surveys completed during 2009. An additional year of surveys to be completed prior to construction. Passerines (small, perching birds) – Protected by federal MBTA. Nationally passerines have seen the greatest mortality at wind farms of any bird group; higher mortality is associated with migration. A broad-front passerine migration is possible through the region. One year of surveys completed for spring and fall migration and breeding birds 2009, and second year to be completed prior to construction. Greater Sage-Grouse – Project outside of critical sage-grouse habitat. Four historical lek locations were documented on or near the project. No sage-grouse were found during 2009 spring surveys. A second year of surveys to be completed prior to construction. Mountain Plover – Several documented sightings inside and near the project area. Plovers nest in short sagebrush often near prairie dog towns. It is a state imperiled species (S2) and a Species of Greatest Conservation Need. Studies have shown impacts from wind farms on nesting frequency and success. Breeding season surveys recommended if present on site. No Mountain Plover were found during 2009 surveys. Small Mammals – Mortality may be elevated due to increased perching opportunities for raptors on structures and transmission lines, and due to road kills. It is recommended that transmission lines be buried and road lengths minimized. Bats – No protected or rare bat species are expected to occur on site, but two migratory species are likely and a third possible. Among all bats, these migratory forest bats have seen the greatest mortality at wind farms. Habitat mapping and analysis for potential bat species and concentration areas is recommended. Active and passive acoustic monitoring for bats is recommended for two seasons prior to construction, and will be carried out during two seasons (summer 2010 and prior to construction) based on discussions with WYGFD. Plants – No federally protected plants identified. One S2 (imperiled in Wyoming) state status plant is likely to occur in the project area; two other S2 species are possible. Site specific surveys of turbine pads, access roads, and transmission line routes are recommended before turbine construction. Habitats of Concern Grassland and Shrub-Scrub Bird Habitat – Several species that utilize grassland and shrub- scrub habitat (i.e., sagebrush) for breeding are experiencing regional declines. High quality habitats should be avoided. One year of breeding bird surveys to characterize bird use of these habitats completed in 2009. Second year of surveys expected prior to construction. Wetland (Riparian) Bird Habitat – Migrants and several declining species are likely to use wetlands and other habitat along streams (i.e., riparian habitat). Avoid placing turbines in these habitats and set turbines >100m away from wetlands. Surveys will identify high use areas. Other Wetlands – Wetlands identified by the National Wetlands Inventory (NWI) may be protected under the Clean Water Act and regulated by the US Army Corps of Engineers. Isolated wetlands are regulated by the Wyoming Dept. of Environmental Quality. Wetlands should be avoided when placing turbines or other infrastructure, and a wetland delineation should be performed if construction is planned near wetlands.
4.2 Field Surveys Because they are vulnerable to regional population declines, if SGCN species occur on the site consultation with the WYGFD is recommended. Special surveys for SGCN species may be necessary. A total of 40 different species were observed during the 2009 field season including, the following SGCN birds were sighted during 2009 surveys: Brewer’s Sparrow, Ferruginous Hawk, Lark Bunting, McCown’s Longspur, Bald Eagle, Burrowing Owl, Redhead, Black Tern, and Sage Sparrow. An active Ferruginous Hawk nest and another large stick nest (possibly an alternative Ferruginous Hawk nest) are present on the site (see attached map). These nests will be examined in the spring raptor nest survey to determine whether they are active in 2010. White-tailed Prairie Dogs occupy most of the site. Although they are locally abundant, they are an SGCN species due to regional population trends. Less is known about the effect of energy development on this species and additional study may be necessary. Swift Fox (an SGCN species) was sighted in the project area. Experience at other energy development projects indicates that impacts would be unlikely and therefore further study is likely not necessary.
4.3 New issues raised by Final WYGFD Recommendations (10/2/2009) Wyoming is developing recommendations for baseline data collection, and a new draft was included with the WYGFD letter dated 10/2/2009 (see attached). This letter stated that the AES survey protocols would be acceptable for avian point counts. They recommend that bat acoustic monitoring be coordinated with them and begin in 2010, and that raptor issues be coordinated with the USFWS. They also recommended that we review their aquatic monitoring recommendations as these have changed recently. The following is a list of additional recommendations that have changed since the original Site Review Amphibian & Reptile Habitat Mapping – Habitat mapping for amphibians and reptiles is recommended within 100m of all proposed roads and within 500m of proposed turbine pads. These maps should identify potential habitat, including vernal pools and playas. Based on results of this mapping, amphibian and reptile monitoring surveys may or may not be warranted. Aquatic Surveys – If any perennial streams are crossed, monitoring will be required to ensure that adverse impacts are not occurring due to runoff from turbine pads and roads, or during construction. If adverse impacts are detected, mitigation techniques will be identified. Monitoring will also be required for all roads with a slope greater than 5%. A Rosgen Level II creek study downstream of the project area is recommended. A monitoring site upstream of the project is recommended to rule out off-site impacts, but won’t be necessary since the headwaters of all streams are within the project boundary. Species of Greatest Conservation Need Analysis – Species of Greatest Conservation Need (SGCN) were identified as part of a national program led by the US Fish and Wildlife Service. SGCN species are those most as risk in a state due to habitat loss, fragmentation, and degradation. The Final WYFGD Recommendations requests that the site be screened for SGCN small mammal and bird species, and if any SGCN species are found during surveys, the developer consult with the WYGFD to consider whether additional survey work is recommended for an SGCN small mammal or bird species. Priority Watersheds – It is necessary to identify whether the project occurs within a state priority watershed. The WYGFD has not identified the project area as part of a priority watershed in any of its prior communications. Priority watershed status will be confirmed through future map analysis and communication with WYGFD
WYOMING GAME & FISH DEPARTMENT SURVEY PROTOCOL REVIEW LETTER
SITE REVIEW FOR BOSWELL SPRINGS WIND FARM ALBANY COUNTY, WYOMING
April 31, 2009
Submitted to: Mr. Paul Martin Intermountain Wind PO Box 353 Boulder, CO 80306
Prepared by: Heather Kieweg, Kim Chapman, and Megan Eichhorst Applied Ecological Services, Inc. 21938 Mushtown Road Prior Lake, Minnesota 55372 Phone: (952) 447-1919 Fax: (952) 447-1920 Email: info.mn@ appliedeco.com
TABLE OF CONTENTS
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EXECUTIVE SUMMARY AES was retained by Intermountain Wind to provide a site review and give recommendations on wind turbine siting in order to avoid potential biological impacts at Boswell Springs Wind Farm. AES conducted a literature review, expert interviews, and analyzed available GIS data. No biological impacts of such magnitude as to prevent the project from proceeding forward were detected. Investigations did, however, reveal several species of concern and landscape features in the general area which suggest careful attention should be paid to the highlighted issues. A brief summary of issues and potential actions is included here (Table 1).
Table 1. Potential Issues of Concern.
Potential Future Studies and Timing of Issue Consideration Recommendations Study Land Ownership & Cultural Resources Public land No protected public land Not an issue documented in or near project area Cultural Resources No sites listed or eligible for Not an issue listing in the National Register of Historic Places Federal Species of Concern Federal Threatened, None documented within Not an issue Endangered and project boundaries. Black- Candidate Animals footed Ferret possible due to proximity of release site. Federal Threatened, None identified. Not an issue Endangered and Candidate Plants Golden & Bald Eagles Protected by federal USFWS recommends a nest March-June BGEPA. Several search be conducted. If a nest is documented sightings present within 4 miles of a within and near the project proposed turbine, 2 years of nest area. monitoring are recommended. Raptors Protected by federal MBTA. Avoid updraft zones. Use modern April – May Present during migration turbine design. Survey to identify & Sept and breeding. No concentration areas. concentrated migration paths are known. Waterfowl/Waterbirds Protected by federal MBTA. Avoid wetlands. Set back turbines Spring & fall Riparian wetlands and >100 meters from wetlands. migration, scattered emergent wetlands Survey for high use areas. summer breeding Passerines Protected by federal MBTA. Passerine migration study May and Broad-front passerine September migration possible through region
Potential Future Studies and Timing of Issue Consideration Recommendations Study State Species of Concern Big Game Edge of antelope winter Not an issue range just southwest of project boundary. Small Mammals Structures and transmission Bury transmission lines. Minimize Not lines may provide increased road lengths. applicable perching opportunities for raptors and increase predation. Road mortality. Ferruginous Hawk Several documented Conduct nest survey in riparian Mating and sightings inside and near the zone and rimrock/eroding areas. rearing project area. season (March-June) Greater Sage-Grouse Two unoccupied lek Conduct a search for active lek March-May locations documented sites following standard protocol. 10 inside, and one nearby. Mountain Plover Several documented Breeding season surveys following May-June sightings inside and near the standard protocol. 15th project area. Bats No protected or rare bat Acoustic survey to document Fall species. Two migratory concentration areas, migration species possible. genera/species, and relative (August- abundance. Desk-top survey for October) possible hibernacula (mines, caves, etc.). Plants One S2 plant within the Conduct surveys of turbine and Species project area documented. road locations before specific Two other possible species. construction. Habitat Grassland and Most bird species protected Avoid dense, native grassland June Shrub/Scrub Bird under federal MBTA. areas. Conduct breeding surveys Habitat Several species are to characterize bird use in both experiencing regional habitats. declines in grassland, few in shrub/scrub. Riparian & Wetland Bird Most bird species protected Avoid riparian habitats and June Habitat under federal MBTA. wetlands. Set back turbines >100 Migrants and several meters from wetlands. Survey for declining species likely to high use areas. use this habitat. Wetlands Federal Clean Water Act Avoid placing turbines or Before final regulates wetland impacts. infrastructure (roads, etc.) in turbine site NWI wetlands may be wetlands. Perform wetland design regulated by USACE and delineation if construction is isolated wetlands by the planned near wetlands. Wyoming DEQ.
Golden/Bald Eagle Golden and Bald Eagles are protected under the Federal Bald and Golden Eagle Protection Act (BGEPA). Historically Golden Eagles have seen significant mortality at wind farms in California, but newer turbine design and more sensitive turbine siting has resulted in reduced mortality. The USFWS
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is recommending nest searches be conducted at wind farm, and that 2 years of nest monitoring be conducted on any nests that are within 4 miles of a proposed turbine. Greater Sage-Grouse The Greater Sage-Grouse is a species of concern to the Wyoming Game and Fish Department (WYGFD). Greater Sage-Grouse are extremely sensitive to disturbance, and are expected to avoid areas developed as wind farms. The project site is located outside of the recently declared critical Sage-Grouse habitats; however, there are records of leks from within the project boundaries. Spring surveys to identify leks will be necessary. The USFWS recommends that no turbines be sited within 5 miles of an active lek. Mountain Plover Mountain Plover is a state imperiled species, but it has been denied for federal listing, therefore has no special legal protection. It nests in short grass prairie and short sagebrush often near prairie dog towns. Wind farm construction at the Foote Creek Rim Facility caused a reduction in nesting frequency and success. There are several records of Mountain Plovers from within the project area. Breeding season surveys should be conducted for Mountain Plover. Raptors Most raptors are protected by the Migratory Bird Treaty Act. While they are not especially vulnerable to impacts from wind turbines, micro-siting of turbines can be helpful to avoid and minimize impacts. Raptors are likely to be present at the site during breeding and migration, although the site does not appear to host a major concentration area for raptors. General guidelines suggest avoiding hill slopes (updraft areas) and ridgelines. Surveys can be useful to determine high and low use areas within the project boundaries for turbine micro-siting. Passerine Migration Migrating passerines have seen the greatest mortality at wind farms, particularly long-distance migrants. Passerine migrants tend to migrate as a broad front across the landscaping, stopping in suitable habitat along the way. Surveys of the passerine migration should be conducted to characterize their use of the site. Bats Although no protected bat species are expected to occur at the proposed wind farm location, developers are being encouraged to assess potential impacts through on-site pre/and post- construction surveys. Bat populations are vulnerable to declines because of their low rate of reproduction, and bat kills have been large at several wind farms. In particular migrating forest bats have seen significant mortality at some wind farm locations during their fall migratory period. Very little is known about bat migration. Acoustic surveys during the migratory period would document the use of the site. Additionally; a desktop search for nearby mines and caves would identify possible concentration areas for other bat species. Grassland & Shrub/Scrub Bird Habitat Grassland bird species are generally on the decline nationwide, and many shrub/scrub nesting birds are declining as well. These habitats support many rare species that are being tracked. Many grassland and shrub/scrub bird species appear to avoid tall structures such as utility towers. Wind turbines, utility towers, and similar structure may lower a bird’s perception of habitat quality, resulting in lower bird densities and reduced breeding output. Small mammals in these environments may be at risk from increased predation if transmission wires are not buried. Grassland habitat should be avoided, since it is home to the highest numbers of sensitive species. Where possible towers should be located on the edge of habitats, and surveys should be conducted to identify breeding grounds and concentration areas.
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Riparian and Wetland Bird Habitat Seven-mile and Spring Creeks contain a variety of wetland and riparian habitats. These habitats are likely important for migrating passerine birds and bat species. Riparian habitats are also utilized by several species in decline regionally. Since the riparian areas and associated wetlands are important biologically and comprise a small percentage of the site, turbines should not be placed within 100m of these areas. Wetlands Wetlands are protected under the federal Clean Water Act. National Wetland Inventory (NWI) wetlands may be regulated by the US Army Corps of Engineers (USACE), and isolated wetlands may be regulated by the Wyoming Department of Environmental Quality (WYDEQ). Construction in wetlands should be avoided, and pre-construction surveys for wetlands should be conducted. Turbine Siting Recommendations • Locate turbines away from riparian habitat, wetlands and grasslands. When possible, turbines should be placed in disturbed or developed areas, agricultural areas and similar places. • Greater Sage-Grouse leks should be identified and avoided. • Proposed tower locations should be surveyed for prairie dog colonies, and if colonies are present proposed tower locations should be relocated 200m away from colony to avoid the attractive nuisance of raptor predation under towers. • Turbines should be set back from the Wheatland No. 3 Reservoir and associated wetlands. • Results of biological surveys should be used to aid in siting wind turbines. • Place turbines singly or in groups, rather than rows. • Minimize site infrastructure. Bury transmission lines in sensitive habitats.
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1. INTRODUCTION Intermountain Wind retained Applied Ecological Services (AES) to provide a site review for a potential wind farm within central Albany County, Wyoming (Appendix 1; Site Location). Design specifications for the wind turbines have not been completed; however, the turbines are expected to be from 1-2 MW, with tower heights of either 80m or 100m and rotors of approximately 77 to 90m diameter. The total height would be 118.5m to 145m, and the lower limits of the rotor swept region would be from 35m to 61.5m. This site review covers the potential impacts from and restrictions to the proposed wind farm— particularly those impacts which would necessitate re-siting of the wind turbines or a high level of environmental review because of potential biological or land ownership issues. Legal authority to protect wildlife is provided to the U.S. Fish and Wildlife Service (USFWS) through the Migratory Bird Treaty Act (MBTA), the Bald and Golden Eagle Protection Act (BGEPA), and the Endangered Species Act (ESA). Under the MBTA and BGEPA the USFWS cannot grant permission for incidental takings. However, the USFWS often enters into memorandums of understanding with developers that, while not legally binding, set up guidelines for project development and management, and promise discretion in prosecution. The Wyoming Game and Fish Department has jurisdiction over all wildlife in the state, but no regulatory authority beyond hunting and fishing regulations. In April 2009, the WYGFD issued Draft Recommendations for Baseline Data Collection and Monitoring of Wind Farms (dated 4/15/2009). This study was underway before these recommendations were issues, and may have a bearing on future work. Wetlands may be regulated by U.S. Army Corps of Engineers (USACE), and isolated non-jurisdictional USACE wetlands may be regulated by the Wyoming Department of Environmental Quality (WYDEQ). Construction and operation of wind energy facilities have the potential to cause some impacts to legally protected wildlife, habitat or plants during construction and operation. The USFWS is currently working on new siting guidelines for wind power developments. These guidelines are anticipated to become available in late 2009. Consulting with the USFWS and Wyoming Game and Fish Department (WGFD) early in the project process is important to establish good relations with these agencies. In past projects the USFWS has been willing to exercise some leniency with corporations that have demonstrated transparency and good faith efforts to reduce and minimize impacts. In conducting this review AES reviewed and utilized a wide number of data sources. Land cover maps of the area obtained from the USDA/NRCS National Land Cover Database were used to create a habitat map of the site. Endangered, Threatened, and Special Concern Species were identified from queries to the Wyoming Natural Diversity Database, and WGFD documents and maps. Risk to individual species and species groups were determined from review of existing literature on avian and bat fatalities, species habitat use, migratory behavior, flight trajectories, U.S. Fish and Wildlife Service (USFWS) documents, local birding checklists, and Breeding Bird Survey data. The Biodiversity Alliance Document “Wind Power in Wyoming: Doing it Smart from the Start” was consulted to identify other issues of concern. Analysis of this information led to the identification of critical issues for the development of this project, including legal, land ownership, migratory, habitat and species-specific concerns. We provide a discussion of how each of these concerns impacts the development of the project site. For protected species and species of conservation concern we provide a discussion of relevant behavioral, life history, and habitat usage, and we identify important habitat and migration use areas within the proposed project area. Finally, we provide recommendations for siting of wind turbines, turbine array layout, land cover management, site infrastructure, and additional surveys.
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2. HABITAT ANALYSIS The Boswell Springs Wind Farm project area is in central Albany County, Wyoming. This area is located in the Rolling Sagebrush Steppe of the Wyoming Basin. The basin is a broad intermontane region dominated by grasslands and shrublands, frequently dominated by big sagebrush. Precipitation averages from 6 to 16 inches per year. The topography consists of rolling plains, with hills, cuestas, mesas and terraces. The project site is relatively flat while the creek descends 60 to 80 feet through the center of the site along Seven-mile Creek, and to a lesser extent along Spring Creek. South and east of the project the terrain descends down to Rock Creek, and to the northeast of the project the landscape ascends and transitions into foothills of the Laramie Mountains. Sagebrush still dominates most of the region, but invasive European annual grasses are replacing sagebrush in some areas (Chapman et al. 2004). Current land cover (Table 2) is nearly entirely shrub/scrub dominated by big sagebrush (Appendix 3; Site Habitats). Grasslands intermingle with the shrub/scrub throughout the project area, particularly in the southwest and northeastern portions of the project. The quality of the sagebrush and grassland habitat may vary significantly across the site. Riparian emergent and woody wetlands occur along Seven-mile Creek and Spring Creek, and isolated emergent wetlands are scattered throughout the site. While there are no large bodies of open water within the project site, the Wheatland No. 3 Reservoir is located just southeast of the project area. This land use distribution is based the USDA/NRCS National Land Cover Database.
Table 2. Habitat types at the Boswell Springs Wind Farm. Habitat Total Area (Acres) % Project Area Open Water 4.2 0.02% Developed Open Space 105.9 0.49% Barren Land 7.6 0.03% Shrub/Scrub 20488.8 94.58% Grassland Herbaceous 656.3 3.03% Woody Wetlands 119.2 0.55% Emergent Herbaceous Wetlands 280.0 1.29%
3. CRITICAL ISSUES 3.1 Land Ownership & Cultural Resources A review of land ownership within the project boundary and immediate surrounding area reveals that most of the land is privately held (Appendix 4, Land Ownership). There are 4 square miles of state owned land within the project area and adjacent and enclosed parcels owned by Bureau of Land Management (BLM). The project area does not contain land ownership that would raise critical concerns (e.g. national park land and viewsheds, national monument land and viewsheds, designated wilderness areas and viewsheds, wilderness study areas & citizen’s proposed wilderness, US Forest Service roadless areas, BLM Areas of Critical Environmental Concern, and other proposed conservation areas) (Molvar 2008). A query of the Wyoming Cultural Research Information Summary Program (CRISP) database found no sites listed or eligible to be listed in the National Register of Historic Places. The database is designed for rapid assessment of potential project areas, and does not replace a complete Cultural Resources Survey. The Historic Rock Creek-Fort Fetterman Stage Road does pass through the
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western portion of the site. This trail is not one of the trails identified as significant for viewshed protection in Molvar (2008). 3.2 Species of Concern Historically, direct impacts from wind farms have primarily been of concern for bird species. However, recent data suggest that bats may be at greater risk than birds. For birds, recent advances in turbine designs and an increased awareness of wind farm siting has reduced per mega-watt impacts, compared to early wind farms such as that at Altamont Pass in California (NRCNA 2007). Impacts to birds have largely been to migrating passerines and to lesser extent raptors. For bats significant mortality has occurred with migrating forest bats in the late summer and early fall. In addition to direct mortality, indirect impacts are of concern for some species. Indirect impacts include habitat loss due to avoidance of turbines, alteration of predator prey relationships, and habitat fragmentation by roads and turbines. For example, Savannah Sparrow is known to breed at lower densities at wind farms than in similar grassland habitat (Leddy et al. 1999, Johnson et al. 2000a). Grouse species that use grasslands are thought to avoid turbine fields (Manville 2004) indirect impacts can be of concern particularly for birds and mammals. Impacts to most mammals and reptiles are generally not expected. While mammals and reptiles may be displaced by construction, and may avoid turbines immediately after construction, they are likely to habituate to turbine presence after a short time and population level impacts are therefore unlikely. However there is some concern about impacts to large mammal species (Elk, Antelope, Mule Deer, Bighorn Sheep, Moose and Mountain Goat) in Wyoming due to roads and disturbance (Molvar 2008). The project site is not considered to be within any of the critical habitats or migration corridors for any of these species (Appendix 2), although critical habitat for Antelope is located just southwest of the project boundary. Small mammals are of less concern, though habitat fragmentation may impact sensitive species. The biggest threat to small mammals is the increase in raptor perches from power lines and power poles. In areas with sensitive small mammals (e.g., Black-footed Ferret), power lines should be buried (Molvar 2008). Significant impacts to insects have, to our knowledge, so far not been documented. While flying and floating insects likely contact the turbines, flight speeds are generally too low to impose mortality risk from impacts with the towers. Flights within the rotor swept area of the turbine blades do result in insect deaths; however, to our knowledge, most potentially at risk insects which are likely to be endangered or threatened species (e.g. butterflies and moths) fly fairly low and are unlikely to fly within the rotor swept area of the turbine blades. Indirect habitat impacts have similarly not been documented, although direct impacts to vegetation could have detrimental effects. In general, fish and other aquatic species are very unlikely to be impacted by wind power facilities provided that adequate measures are taken to prevent erosion and siltation during construction. Similarly, plant species are unlikely to suffer population level effects, since the wind turbine footprint is relatively small. Effects to individual plants can be eliminated by siting turbines (and associated infrastructure) in agricultural lands, avoiding new road construction where possible, and doing site-specific surveys and micro-siting ahead of time.
3.2.1 Endangered, Threatened, and Special Concern Species The State of Wyoming affords legal protection only to animal and plant species that are also listed under the Federal Endangered Species Act. However, many other species are tracked because of their local or national rarity and endangerment. While these species do not have a legal protected status, it is recommended that impacts be avoided or mitigated where possible. A search of the Wyoming Natural Diversity Database (2009) revealed historic and unconfirmed records of the federally endangered Black-footed Ferret (Mustela nigripes) within 5 miles of the
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project boundary (Table 3). The federally threatened Canada Lynx (Lynx canadensis), and Greenback Cutthroat Trout (Oncorhynchus clarkia stomias) are also listed as potentially found near the project area. However, the Lynx primarily uses subalpine habitat, and the Greenback Cutthroat Trout is thought to be extirpated from Wyoming. Bald Eagles (Haliaetus leucocephalus), and Golden Eagles (Aquila chrysaetos) (protected by the federal Bald and Golden Eagle Protection Act) occur within the project boundary. See discussion of these species below. To our knowledge, there are no reports of large mammals, such as Lynx, being impacted by wind farm development. Fish are also unlikely to be impacted by the project so long as erosion is controlled during construction and soils are stabilized after construction. Bald and Golden Eagles have experienced wind turbine mortality. Beginning in the 1990s, modifications in turbine design have greatly reduced these impacts. Many state rare species have been documented within five miles of the site and are likely to occur here (Table 3). These species have no legal protection, but avoidance and mitigation of impacts are recommended. Of these several are passerine (perching) grassland or sagebrush dwelling birds, including Grasshopper Sparrow (Ammodramus savannarum), Sage Sparrow (Amphispiza belli), McCowan’s Longspur (Calcarius mccownii), Chestnut-collared Longspur (Calcarius ornatus), Loggerhead Shrike (Lanius ludovicianus), and Brewer’s Sparrow (Spizella breweri). These birds are unlikely to be directly impacted by the wind farm project as they tend to fly beneath the rotor-swept height. However indirect impacts to grassland and sagebrush birds are of concern (see Section 3.3). These may include the Greater Sage-Grouse (Centrocercus urophasianus), and Mountain Plover (Charadrius montanus) which occur in the project area and are sensitive to development (see discussion below). Raptors of open country are likely to be present: Ferruginous Hawk (Buteo regalis), and American Peregrine Falcon (Falco peregrinus anatum). Among species associated with wetlands, Sandhill Crane (Grus canadensis) is possibly occasionally present in the project area during migration. Long-billed Curlew (Numenius americanus) may possibly breed within the project area, but is unlikely to fly within the rotor-swept height. Two rare small mammals may occur in the project area: White-tailed Praire Dog (Cynomys leucurus) and Wyoming Ground Squirrel (Spermophilus elegans). Swift Fox (Vulpes velox) also occurs within the project area, but is unlikely to be significantly impacted by the project. Possible impacts include increased mortality along roads, and increased access and predation by coyotes. The remaining species likely to occur in the project boundary are plants which are easily avoided with adequate pre- construction site surveys and planning. The project area does not have significant open water, but the large Wheatland Reservoir No. 3 is located to the southeast of the project area. This reservoir is designated a bird habitat conservation area (Molvar 2008). Several rare waterfowl and waterbirds are associated with this reservoir, including Clark’s Grebe (Aechmophorus clarkii), Ring-necked Duck (Aythya collaris), Bufflehead (Bucephala albeola), Common Loon (Gavia immer), Herring Gull (Larus argentatus), California Gull (Larus californicus), Black-crowned Night-heron (Nycticorax nycticorax), American White Pelican (Pelecanus erythrorhynchos), American Avocet (Recurvirostra americana), and Caspian Tern (Sterna caspia). Other species reported by the database are located outside but within five miles of the site. The Sage Thrasher (Oreoscoptes montanus) has a range primarily to the west of the project. While the historic range of the Grizzly Bear (Ursus arctos horribilis) included the sagebrush habitat, today it is restricted to more mountainous regions, and not found within the project area.
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Table 3. Rare biological features within a five mile buffer of the project site. Likely State Fed. Global Present Scientific Name Common Name Rank1 Status2 Rank3 Habitats at Site4 Birds Sagebrush basins and foothills, Centrocercus Greater Sage- generally close Breeding urophasianus Grouse S4 P G4 to water Likely Open grasslands and shrublands especially S3B, around cliffs Breeding Aquila chrysaetos Golden Eagle S3N BGEPA G5 and canyons Likely Wooded areas usually along Haliaeetus S3B, rivers, lakes, Breeding leucocephalus Bald Eagle S5N BGEPA G5 reservoirs Likely Sparse shortgrass or Charadrius mixed grass Breeding montanus Mountain Plover S2 LD G3 prairie Likely Medium height grass, especially Chestnut-collared meadows Breeding Calcarius ornatus Longspur S1 G5 around ponds Likely Sparsely vegetated Calcarius Mccown's shortgrass Breeding mccownii Longspur S2 G4 prairie Likely Medium to tall sagebrush Breeding Amphispiza belli Sage Sparrow S3 G5 shrubland Likely Open country with scattered Lanius Loggerhead trees and Breeding ludovicianus Shrike S3 G4 shrubs Likely Mid-grass prairie, tall- grass prairie, hay meadows, Ammodramus Grasshopper and open Breeding savannarum Sparrow S4 G5 savanna Likely Open grasslands and shrublands especially S4B, around cliffs Breeding Buteo regalis Ferruginous Hawk S5N G4 and canyons Likely
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Likely State Fed. Global Present Scientific Name Common Name Rank1 Status2 Rank3 Habitats at Site4 Sagebrush foothills and medium-height sagebrush in basins; mountain Breeding Spizella breweri Brewer's Sparrow S5 G5 mahogany hills. Likely Mountainous zones or cliffs Falco peregrinus American near large lakes Breeding anatum Peregrine Falcon S2 DM G4 and rivers Marginal Meadows, pastures, Numenius Long-billed shorelines, and Breeding americanus Curlew S3B G5 marshes Possible Meadows, marshes, S3B, shorelines and Migration Grus canadensis Sandhill Crane S5N G5 grain fields Unlikely Lakes, reservoirs, and Sterna caspia Caspian Tern S1 G5 rivers. No Aechmophorus Ponds, lakes, clarkii Clark's Grebe S1B G5 and reservoirs No S1B, Ponds, lakes, Gavia immer Common Loon S2N G5 and reservoirs No American White Ponds, lakes, Pelecanus Pelican (Breeding rivers, and erythrorhynchos Colonies) S1B G3 reservoirs No Lakes, ponds, rivers, and Bucephala albeola Bufflehead S2B G5 reservoirs No Lakes, reservoirs, wet California Gull meadows, fields (Breeding and garbage Larus californicus Colonies) S2B G5 dumps No Marshes and Nycticorax Black-crowned wooded nycticorax Night-Heron S3B G5 streams No Marshes, Recurvirostra ponds, and americana American Avocet S3B G5 shores No Ring-necked Rivers, lakes, Aythya collaris Duck S4B G5 and reservoirs No Tall sagebrush Oreoscoptes and montanus Sage Thrasher S5 G5 greasewood No Lakes, Herring Gull reservoirs, wet (Breeding meadows, and Larus argentatus Colonies) SNA G5 fields No
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Likely State Fed. Global Present Scientific Name Common Name Rank1 Status2 Rank3 Habitats at Site4 Mammals Shortgrass prairie, sage- grasslands, particularly sparsely vegetated areas such as prairie Breeding Vulpes velox Swift Fox S2 LD G3 dog towns Likely In or near prairie dog colonies, short Black-footed or mixed-grass Breeding Mustela nigripes Ferret S1 FE G1 prairie Possible Grassland and shrub-grass communities White-tailed with loose Breeding Cynomys leucurus Prairie Dog S3 LD G4 sandy soils Possible Open habitats from sage Spermophilus Wyoming Ground grasslands to Breeding elegans Squirrel S3S4 G5 alpine meadows Possible Mature subalpine forest, typically Lynx canadensis Canada Lynx S1 T G5 above 1,900m No Montane regions of Ursus arctos G4T3T northwest horribilis Grizzly Bear S1 FT 4 Wyoming No Fish South Platte Oncorhynchus Greenback River, and clarkia stomias Cutthroat Trout SX T G4 tributaries No Plants Barren cushion plant and sparse Machaeranthera Colorado spiny grassland coloradoensis aster S2 G2 communities Likely Dry, rocky limestone Sphaeromeria Laramie false sandstone simplex sagebrush S2 G2 pebble plains Marginal Selenium-rich shale-clay slopes, barren plains, and Ward's disturbed Oonopsis wardii goldenweed S3 G3 roadsides Marginal
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Likely State Fed. Global Present Scientific Name Common Name Rank1 Status2 Rank3 Habitats at Site4 Moist sandy to muddy banks of streams, stock Persistent sepal ponds and man- Rorippa calycina yellowcress S3 G3 made reservoirs Marginal
1S1 – Critically Imperiled; S2 – Imperiled; S3 – Rare; S4 – Apparently Secure; S5 – Demonstrably Secure; B – Breeding Rank; N – Non-breeding Rank; A – Accidental; X - extirpated 2FE – Federal Endangered; FT – Federal Threatened; FC – Federal Candidate; BGEPA – Bald and Golden Eagle Protection Act; DM – Delisted; P – Proposed; LD – Listing Denied 3G1 – Critically Imperiled; G2 – Imperiled; G3 – Vulnerable; G4 – Apparently Secure; G5 – Secure 4 For Wildlife: Breeding Likely = high quality breeding habitat present and in species range; Breeding Marginal = marginal breeding habitat present and in species range, or habitat present, but outside or at edge of breeding range; Breeding Possible = in species range and breeding habitat unconfirmed, but possible; Migration Likely = on migratory route & stopover habitat present; Migration Unlikely = migratory presence possible, but less likely due to migratory route location or stopover habitat quality; No = breeding & migratory habitat absent For Plants & Communities: Likely = high quality habitat present; Marginal = habitat marginal or possible; No = habitat absent.
3.2.1.1 Bald and Golden Eagle The Golden Eagle (Aquila chrysaetos) is ranked S3, rare, for both breeding and migratory populations, and globally ranked G5, secure. They are protected under the federal Bald and Golden Eagle Protection Act. Because of their broad wingspan they are extremely susceptible to electrocution. Other threats include poison set out for coyotes and land use changes (NatureServe 2009). Golden Eagles have a broad habitat association, utilizing open country that includes deserts, grasslands, savannas and woodlands. They nest on cliffs, ledges, or in large trees. Golden Eagles have seen high mortality rates at the Altamont Wind Farm site (Smallwood and Thelander 2008), where the towers were placed in frequent hunting and migratory areas. However, since that development, turbine design has changed dramatically, reducing the number of bird kills. For example, fewer larger blades appear to be easier to see and do not have the “smear” associated with older turbine construction. In addition, solid tubular support towers do not provide the perching opportunities previously implicated in raptor mortality. The Wyoming Natural Diversity Database (2009) has records of Golden Eagle scattered through the south and eastern portions of the project area, and surrounding the site. Surveys should be completed to identify Golden Eagle nest locations, and to identify important feeding grounds. If areas of concentrated feeding activity (e.g. prairie dog colonies) exist, they should be avoided. Bald Eagles (Haliaeetus leucocephalus) are protected under the Bald and Golden Eagle Protection Act. They are ranked state S3 (rare) for breeding populations and S5 (demonstrably secure) for non- breeding populations. Globally they are considered demonstrably secure (G5). The Wyoming Natural Diversity Database (2009) reported Bald Eagles within the proposed wind farm site. Bald Eagles typically prefer open water for feeding and old trees of appropriate structure for nesting. They may also scavenge for road kill. There is one record of a bald eagle within the project site. Since there is no significant open water at the site their primary foraging areas are probably the Wheatland Reservoir No 3 to the southeast of the project area. To date few to no Bald Eagles have been killed at wind turbine facilities. Wind turbines have changed dramatically in the last few years, reducing the number of bird kills, as described above.
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The USFWS has recently developed a guidance document for the management of Bald and Golden Eagles at wind turbine locations. If eagle nests are located within 4 miles of a proposed wind turbine, the USFWS recommends 2 years of pre-construction studies that identify feeding and roosting areas, home ranges and movement patterns. Based on this data the USFWS will make a determination of whether a take or disturbance is anticipated. Post construction monitoring will be required to determine actual impacts.
3.2.1.2 Ferruginous Hawk The Ferruginous Hawk (Buteo regalis) is state ranked S4 (apparently secure) for breeding and S5 (demonstrably secure) for non-breeding. Globally it is ranked G4, apparently secure. Threats include habitat loss, accidental poisoning, and human disturbance. It is particularly sensitive to disturbance during the nesting season with remote nests typically having greater nesting success (NatureServe 2009). Ferruginous Hawks utilize open habitat including grasslands, shrub/scrub and desert areas. Common nesting locations include tall trees and willows along riparian corridors or on steep slopes, ledges, and river-cut banks. The Wyoming Natural Diversity Database (2009) has records of Ferruginous Hawk scattered in and around the project area, particularly in the south and eastern portions of the project area. Ferruginous Hawks should be confirmed with field surveys and their general location at the site documented. A nest search may be requested by regulators, depending on the results of the field surveys. This search can be accomplished during the growing season.
3.2.1.3 Greater Sage-Grouse The Greater Sage-Grouse (Centrocercus urophasianus) is considered S4/G4 (apparently secure) in Wyoming and globally, but it has been proposed for federal listing. It has seen significant loss of habitat, and now only occupies 56% of its former range. Decline has been the result of fragmentation and degradation of sagebrush habitat. The rate of decline has decreased significantly since the mid-1980’s (NatureServe 2009). While its condition appears to have stabilized, lingering concerns cause wildlife biologists to remain cautious about this species. The Greater Sage-Grouse uses a wide variety of sagebrush habitats throughout the year. In the early spring they gather at leks in relatively open sites surrounded by sagebrush. The females require nutritious forb forage before nesting, and nesting habitat consists of a dense cover of both sagebrush and grasses. In summer they move to areas with greater moisture availability, such as riparian zones, and in winter they concentrate in areas with tall sagebrush that remains exposed above the snow cover (NatureServe 2009). Impacts to the Greater Sage-Grouse from wind farms are expected to be indirect in nature. They do not typically fly within the rotor swept height, but they are sensitive to human disturbance. Road construction, maintenance, and vehicle traffic associated with a wind farm may all cause disturbances. The wind turbines themselves may also trigger avoidance behavior by grouse, as the grouse avoid areas with trees. In one project in Idaho, installation of meteorological towers caused the abandonment of seven out of nine leks (Molvar 2008). Wyoming Executive order 2008-2 identifies core habitat areas for the Greater Sage-Grouse and only allows new development activities that will not cause declines in Greater Sage-Grouse population. The project lies outside of this core habitat, but the Wyoming Natural Diversity Database located several sightings on or near the project area. WGFD has records of two unoccupied leks in the site (Appendix 2). USFWS recommends keeping wind turbines 5 miles away from active Greater Sage- Grouse leks (Manville 2004), and known wintering grounds should also be avoided completely. Additionally, in Greater Sage-Grouse habitat, transmission lines should be buried to avoid increases in predation caused by the addition of raptor perches and the tendency of tall structures to cause habitat avoidance (Molvar 2008). Early spring surveys of the site to identify Greater Sage-Grouse leks will be necessary.
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3.2.1.4 Mountain Plover The Mountain Plover (Charadrius montanus) is S2 (state imperiled), G3 (globally vulnerable), but was denied for federal listing. Recently populations have been stable, but historically the population has contracted seriously. Market hunting may have been one of the initial causes of population decline. Other causes include conversion of short-grass prairie to agricultural land, decline of prairie-dog towns which provided foraging and nesting habitat, and habitat loss in wintering areas (NatureServe 2009). The plover nests in high plains/short grass prairie, and areas of short sagebrush. It is often associated with prairie dog towns (Wyoming Natural Diversity Database 2009). Construction, operation or maintenance activities at a wind farm project on the Foote Creek Rim Facility caused a severe reduction in nesting frequency and success of Mountain Plovers (Johnson et al. 2000b). The Biodiversity Alliance recommends avoiding all Mountain Plover nesting habitat (Molver 2008). There are records of Mountain Plovers from several locations along Fetterman Road within the project area. Surveys should be conducted for Mountain Plover and Mountain Plover habitat during the breeding season.
3.2.1.5 American Peregrine Falcon The American Peregrine Falcon (Falco peregrinus anatum) is state rank S2 (imperiled) and globally apparently secure (G5). Federally it has been delisted. While still a threat to population health, the reduction in organochlorines in the environment (e.g., DDT), allowed the population to recover. Additional current threats include habitat loss and human disturbance (NatureServe 2009). The Peregrine Falcon typically nests on a ledge or in a hole on the face of a rocky cliff. It utilizes a wide variety of habitats near its nesting locations including open forests, open areas, mountains, and developed areas. During the non-breeding season it occurs in areas of prey concentrations. Wyoming Natural Diversity Database (2009) has two Peregrine Falcon records from nearly 30 years ago, one in the southeastern portion of the site near the Wheatland Reservoir, and one southeast of the site.
3.2.1.6 White-tailed Prairie Dog The White-tailed Prairie Dog (Cynomys leucurus) is state ranked S3 (rare) and globally apparently secure. It was denied for federal listing. Threats include predation and flea-borne sylvatic plague (NatureServe 2009). They form loose colonies in xeric grasslands, and prefer a mixture of shrubs and grass. They tend to prefer higher elevations with more diverse forb and grass cover than the Black-tailed Prairie Dog. (NatureServe 2009). Sightings according to the Wyoming Natural Diversity Database (2009) are scattered around the project area, and appropriate habitat is located within the project area. The prairie dog is unlikely to be directly impacted by the wind farm development, but could suffer from habitat impacts such as increased predation from raptors perching on power poles and transmission lines.
3.2.1.7 Black-footed Ferret The Black-footed Ferret (Mustela nigripes) is state ranked S1 (critically imperiled) and critically imperiled globally as well. It is a federally endangered species. The species was extirpated through most of its ranger through prairie dog and predator control programs. A major obstacle to its re- introduction and recovery is the species’ susceptibility to sylvatic plague. The ferret is associated with prairie dog colonies in open grassland habitat. Historic occurrences are recorded in the Wyoming Natural Diversity Database (2009). Habitat is present at the project location, but no confirmed recent records exist. The Shirley Basin Black-footed Ferret Recovery Area boundary is located approximately 3 miles west (although the release site is significantly to the
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northwest) of the project and the ferret may appear at the wind farm in the future. Even if present at some future time, the wind farm project is unlikely to cause negative impacts.
3.2.1.8 Wyoming Ground Squirrel The Wyoming Ground Squirrel (Spermophilus elegans) is state S3S4 (rare to apparently secure) and globally secure. Sylvatic plague and poisoning are the largest threats (NatureServe 2009). It utilizes grassland and shrub/scrub habitat with soils suitable for digging burrows (NatureServe 2009). Wyoming Natural Diversity Database (2009) sightings are located south and west of the project area, and appropriate habitat is located in the wind farm project area. The ground squirrel is unlikely to be directly impacted by the wind farm development, but could suffer from habitat impacts such as increased predation from raptors perching on power poles and transmission lines.
3.2.2 Bird Species Groups Most bird species are protected under the Migratory Bird Treaty Act (MBTA) administered by the USFWS. Available data suggest that the wind site does not lie within any known significant migration routes. However, in order to identify potential migratory birds in the project area, we used the nearest USFWS bird list checklist from the Warren Air Force Base (Air Force and the National Fish and Wildlife Foundation, No Date). These checklists typically rate the abundance of all birds passing through an area by month or subdivisions of months. The Air Force base is located approximately 100 miles southeast of the project area (Appendix 5). To this checklist we added the USGS Breeding Bird Survey population trend data to identify bird species with declining populations. The data were obtained for the Wyoming Basin (BBS Region 86) and USFWS Region 6, where the project is located. Not all species are common enough to have trend data, but those with data indicate the status of groups of birds and birds associated with different habitats. Potential impacts to large numbers of bird species are best considered by groups because these have experience similar levels of impacts from wind farm developments. In addition, considering risk by habitat allows different levels of risk in a project to be mapped.
3.2.2.1 Breeding Passerines (Perching Songbirds) and Other Small Birds In general, breeding birds are unlikely to experience collisions. At the Buffalo Ridge Wind Resource Area, Minnesota, Osborn et al (1998) found that 70-75 percent of resident birds flew below 21 meters and avoided the turbine blade height. In the Upper Midwest species most at risk from collisions with turbines are those that regularly fly in the rotor swept height, such as Horned Lark and European Starling. However, a close examination of the Buffalo Ridge data have led many wildlife biologists involved in wind farm impact studies to conclude that flight height and abundance are less important than the flight behavior of individual species or groups of birds. No published study has summarized this general understanding, however. Riparian and Grassland habitat contain the largest numbers of birds in decline in the Wyoming Basin and USFWS Region 6. The riparian habitat along the seven mile creek is likely to serve as habitat for several species in decline in Wyoming: Bank Swallow, Barn Swallow, Black-billed Cuckoo, Black-capped Chickadee, Brown Thrasher, Lazuli Bunting, MacGillivray’s Warbler, Northern Flicker, Veery, and Yellow-rumped Warbler. The shrub/scrub and grassland habitat is also likely to serve as habitat for several species in decline in Wyoming including: Cassin’s Sparrow, Chestnut-collared Longspur, Common Nighthawk, Grasshopper Sparrow, Killdeer, Lark Bunting, Loggerhead Shrike, Northern Bobwhite, and Vesper Sparrow. Most of these species utilize grassland rather than big sagebrush-dominated shrub/scrub.
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3.2.2.2 Migrant Passerines (Songbirds) and Other Small Birds Migrant passerines appear to have high mortality at wind farms (NRCNA 2007). Some of these are experiencing regional declines according the USGS Breeding Bird Survey. The collision risk to passerines occurs mainly during migration. In general, flight heights during migration are well above the height of wind turbines. However, birds appear to be vulnerable during inclement weather when visibility is reduced. Even during inclement weather, the number of birds impacted is unlikely to be high during any single event. Passerines typically migrate in a broad “front” across the landscape (Kingsley and Whittam 2003), and large, dense flocks are unlikely to fly through wind farms (NWCC 2004). In particular, long distance migrants (from South America, etc.) appear to be most at risk from wind turbines. Long distance migrants fly high while the short distance migrants (e.g., from southern U.S.) fly much lower, and pass below the rotor swept area. There is an element of habitat selection during migration. Long distance migrants in particular tend to utilize forest and brushy habitat during migration stopovers, rather than open agricultural land. Short distance migrants tend to move through landscape within their preferred habitat types. Forest and brushland is limited to riparian habitats mostly in the center of the site. These habitats could provide stopover habitat for both long-distance and short-distance migrants. The shrub/scrub and grassland habitat is less likely to attract migrating passerines. Surveys during spring and migration would help identify important habitats and locations for migrating passerines.
3.2.2.3 Raptors In general, hawks appear to have moderate to low collision risk from wind turbines (Coberly, unpublished report; De Lucas et al. 2004). De Lucas et al. (2004) found raptors appear to avoid wind turbines and increase their soaring height on approach. However, the large number of Golden Eagles killed at the Altamont Pass (Smallwood and Thelander 2008) wind power facility in California raised concerns about the potential for impacts and concern persists in the general public unfamiliar with recent studies at wind farms with modern turbines. The proposed site is not located on a major concentrated raptor migration route as far as is known. Raptors using the site are typical of open country raptors (e.g. Swainson’s Hawk, American Kestrel). The Wheatland No. 3 Reservoir will draw raptors to scavenge fish (e.g. Bald Eagle, Golden Eagle, Turkey Vulture). Other raptors may use the riparian woodlands. The Wyoming Natural Heritage Database (2009) has records of Bald Eagle, Ferruginous Hawk, Golden Eagle, and Peregrine Falcon within the project area, and considers the area to have likely habitat for four other raptor species of concern: Short-eared Owl (Asio flammeus), Burrowing Owl (Athene cunicularia), Merlin (Falco columbarius), and Eastern Screech Owl (Otus asio). American Kestrel, Short-eared Owl, and Swainson’s Hawk are on the decline according to breeding bird survey data. General guidelines for raptors suggest avoiding hill slopes (updraft areas) and ridgelines. Since the site has no distinct ridgelines or steep south and west facing slopes that would generate updrafts, it is not expected that raptors will concentrate on the site. Rather, it is expected that they will be dispersed across the site for movement and foraging. Prairie dog colonies may serve as concentration areas on the site, and increased activity may be seen near the Wheatland Reservoir. Pre-construction surveys can define risk areas and minimize potential impacts by moving turbines to avoid high use areas. Once turbine sites are known, surveys can identify if nearby prairie dog towns pose a risk to raptors hunting near turbines. Use of modern turbine designs with larger, more slowly rotating turbine blades and solid support structures also help prevent impacts (Osborn et al. 2000).
3.2.2.4 Waterbirds/Waterfowl Typical migratory flight heights of waterfowl are much higher than the rotor swept area of wind turbines (Kerlinger 1995) and historically few waterfowl have been killed at wind farms. This may
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be due to avoidance behavior—waterfowl are observed to avoid turbines—or past wind farms siting in order to avoid waterfowl concentrations. However, migrating waterfowl may be vulnerable when a) ascending or descending from water bodies, b) feeding in and near wind farms, c) during inclement weather, d) on early morning and late evening flights if visibility is reduced, and e) when turbines are near or between roosting and feeding sites. Many waterbirds appear to be exceptionally adept at avoiding wind turbines and documented mortality is very low (Coberly unpublished data). Shorebirds, such as Willets and Greater Yellowlegs, are agile flyers. Documented impacts to these species are rare. Night-migrating waterbirds are at the highest risk. Cranes and large waterbirds may be especially susceptible to wind turbine impacts due to their large size and low maneuverability. The project area has little open water and is unlikely to be a significant location for either breeding or migrating waterfowl or waterbirds. Great Blue Herons may use the riparian habitat. They are declining in the region according to Breeding Bird Survey data. The Wheatland No. 3 Reservoir is located to the southeast of the site, and many records of rare waterfowl and waterbirds are reported.
3.2.3 Bats Impacts to bat species have become an increasing concern in recent years. Little is understood about bat migrations and the potential for wind farm impacts generally. Bat kills have been large at several wind farms (e.g. Arnett 2005), and bat populations are vulnerable to decline because of their low rate of reproduction. When flying in the rotor swept height, bats may avoid most direct collisions with rotor blades, but they are unable to withstand the pressure change caused by the passing rotors. Lung hemorrhaging has been found in 90% of examined bat fatalities (Baerwald et al. 2008). In general, few resident bats seem to be killed at wind farm facilities and most wind farms have not documented large bat kills. However, migratory bats have been affected in some areas. At one wind farm in West Virginia an estimated 1,364–1,980 bats were killed over a 6-week period in 2004 (Arnett 2005). Although the number of deaths seems large, biologists have difficulty estimating the biological significance of such mortality because little is known about bat reproductive rate, the mortality rate at different ages, and so on. Only a few species have this type of information (O’Shea and Bogan 2003). Temperate-zone bats reproduce once per year and most bear one or two young. Biologist are concerned by this low reproductive rate, the potential high mortality at some wind farms, and the large number of US species considered endangered or at risk. Of 45 species in the continental US, six are federally endangered and 20 are at risk. Many bat populations are also declining as a result of White Nose Syndrome, a lethal disease possibly of fungal origin that is spreading through bat hibernacula in the Northeast (Bat Conservation International 2009).
Biologists have documented deaths of 11 species of bat at wind turbines in North America (Johnson 2005). Most fatalities (>90%) involve hoary bats, eastern red bats, silver-haired bats, and tri-colored bats. These are called forest bats because they are largely restricted to forests. Most bat- turbine collisions take place in August and September, with relatively few deaths reported at other times of year (Fig 1; Johnson 2005, Arnett et al. 2008).
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Figure 1. Temporal pattern of bat mortality at wind farms (from Johnson 2005).
A similar peak in mortality is not seen in spring (Fig. 1). The difference in spring and fall mortality is not understood. Biologists speculate that spring migrants follow different routes, have smaller population sizes due to winter mortality, include many young bats that are susceptible to turbine collisions, collide when engaged in territorial behavior related to mating, spread the migration over a longer period than fall, or are attracted to turbines by mistaking them for trees which are used in mating (Cryan 2003; Zinn and Baker 1979, Cryan 2008). Infrared imagery has shown bats investigating towers, passing by multiple times, and landing on stationary blades (Horn et al. 2008). Bat activity and mortality appear related. Mortality is often associated with passing weather fronts and nights with low-wind speed when bats might prefer to migrate (Arnett et al. 2008). Bat activity is often concentrated in the hours after sunset when insect activity is greatest (Horn et al. 2008). Feathering turbine blades at low wind speeds (less than 4m/s) during the fall migration had been proposed as a mitigation strategy, but there is a cost in reduced energy production. Bat flight height may be related to turbine collisions. A study performed by Dr. Alan Kurta of Eastern Michigan University (Kurta, unpublished data) indicated that the total number of bats at 55m was less than bat numbers at 2 or 35m, but that hoary bat was more common at 55m, which is in the rotor swept height. While most activity of bats would be beneath the rotor-swept area, hoary bats are more abundant at heights that put them at risk of collision. The migration altitude of bats is largely unknown, but bats have been reported at an altitude of nearly 8,000 feet (Griffin and Thomson 1982; Peurach 2003). Hoary bats, red bats, and silver-haired bats migrate up to 1,200 miles each spring and autumn. Older anecdotal observations suggest that these bats may migrate in flocks (Carter 1950; Thomas 1921), even during the day (Jackson 1961; Hall 1946; Mumford and Whitaker 1982). The few data available suggest that spring migration of forest bats begins in early April and peaks in early to mid- May. The southward migration peaks in late August and early September, but extends to November and December. Limited data suggest that collisions with wind turbines are less common in agricultural fields and open habitats than in forested areas (Johnson 2005). However, no consistent pattern between
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habitat and mortality has been established (Arnett 2008). Many species of bat will forage primarily in woodlands or along wooded edges and less often over open land (e.g., Furlonger et al. 1987). Bats are known to follow treelines, rivers and other linear features while foraging or moving between roosting and feeding areas (Murray and Kurta 2004; Verboom and Huitema 1997). Anecdotal reports indicate that bats also follow linear features when migrating (e.g., ridgetops, rivers, and coastlines) (Arnett 2005; Cryan and Veilleux in press; Hall 1962; Kurta et al. in press; but see Larkin 2006). Consequently, wind turbines placed in the uniform shrub/scrub areas of the site will likely pose a low risk to bats in comparison to turbines located in wooded habitats, along rivers and shores, and perhaps ridgelines. Eighteen bat species occur in Wyoming (Table 4) (Bat Conservation International 2009). All are considered species of special concern in the state due to low reproductive rate and high conservation need (Hester and Grenier 2005). Four species (Western Small-footed Myotis, Little Brown Myotis, Fringed Myotis, and Big Brown Bat) are likely to occur at the site. Four others (Hoary, Silver-haired, Townsends’ Big-eared and Pallid Bats) may possibly occur in the project area. The site either lacks appropriate habitat or is out of the range of the remaining species. Of those species likely present at the site, the migratory forest bats (Silver-haired and Hoary Bats) experienced large impacts at some wind farm facilities. These bats spend summers in the northern United States and Canada (Cryan 2003; Kurta 1995). They may migrate through the site in spring and autumn. While their primary habitat is forest, they may stop in wooded riparian habitats during migration but little is known of their exact migration pathways. The other potential species at the site (Western Small-footed Myotis, Little Brown Myotis, Fringed Myotis and Big Brown Bat) are not migratory and to date are not significantly affected by wind farms (Arnett et al. 2008).
Table 4. Bats of Wyoming Likely Scientific Impacts Common Name Habitat Migratory Present Name Likely at Site Various, but Eptesicus Big Brown Bat mostly deciduous No Yes No fuscus forests Myotis Western Small- Arid grassland/ No Yes No ciliolabrum footed Myotis shrubland Forests, Myotis Little Brown developed areas, No Yes No lucifugus Myotis and wetlands Conifer and mixed Myotis Fringed Myotis woodland, and No Yes No thysanodes grassland Lasionycteris Silver-haired Bat Forests Yes Possible Yes noctivagans Lasiurus Hoary Bat Forests Yes Possible Yes cinereus Antrozous Arid deserts and Pallid Bat No Possible No pallidus grasslands Arid desert Corynorhinus Townsend’s Big- western scrub and No Possible No townsendii Eared Bat pine forest
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Likely Scientific Impacts Common Name Habitat Migratory Present Name Likely at Site Lasiurus Eastern Red Bat Forests Yes No Yes borealis Nyctinomops Big Free-tailed Desert and Yes No Yes macrotis Bat Grassland Tri-colored Bat Perimyotis Forest edges and (formerly Eastern Yes No Yes subflavus agricultural areas Pipistrelle) Tadarida Mexican Free- Various Yes No Yes brasiliensis tailed Bat Montane conifer Euderma Spotted Bat forest, desert, and No No No maculatum cliff faces Desert scrub, Oak Myotis California Myotis and Ponderosa No No No californicus Pine forests Long-eared Myotis evoits Conifer forest No No No Myotis Myotis Northern Myotis Forests No No No septentrionalis Woodlands Long-legged including pinyon- Myotis volans No No No Myotis juniper and conifer forests Myotis Forests, forage Yuma Myotis No No No yumanensis over open water
An acoustic survey during the fall migration would greatly increase our understanding of the use of the site by bats. The survey would be timed to coincide with the migration and also detect resident bats. Although it is not possible to differentiate some species from others, the number of calls and the inferred identity of species would define the level of use in riparian areas versus shrub/scrub areas and permit an assessment of risk. Mines and caves in the project area and surroundings should also be identified in order to understand the potential for bat hibernacula in and near the wind farm. 3.3 Habitats of Concern Avoiding highly sensitive habitats generally reduces impacts to sensitive species, may reduce the potential for listing of some species, and is favorably viewed by USFWS and State regulatory agencies.
3.3.1 Habitat Fragmentation Habitat fragmentation is an emerging issue in wind farm siting. Fragmentation is the process of dividing (fragmenting) continuous, large blocks of habitat into smaller, more isolated parcels. Fragmentation can be caused by the design of access roads, transmission lines, and towers in high quality habitat areas. It has many negative effects. It leads to population isolation, increased
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inbreeding, and vulnerability to random catastrophic events. Fragmentation can decrease habitat quality. Some species do not use small habitat patches. Fragmentation increases edge effects, such as nest predation and invasion by non-native species. Fragmentation also puts barriers between micro-habitats that some species use at different points in their life cycle. For example, frogs and turtles use wetlands to breed and overwinter, and forests or upland meadows to feed. A road placed between these habitats creates problems. While habitat fragmentation is not strictly recognized in the ESA, MBTA or other regulatory documents, best management practices recommend avoiding and minimizing habitat fragmentation during project planning. To avoid and minimize habitat fragmentation, place turbines where possible in already disturbed land; away from large habitat patches; at edges rather than centrally in habitat patches; outside of or at edges of flyways rather than inside flyways; and adjacent to, rather than between, large habitat patches. The northern-central and eastern portion of the project has been identified as a core habitat area in the Heart of the West Conservation Plan (Appendix 6) (Jones 2004). This conservation plan was developed with a computer algorithm that identified key conservation sites. The algorithm focused on many factors including habitat for three key focal species Sage-Grouse, Wolf and Cutthroat Trout. The project site was probably identified because Sage-Grouse habitat is present. The core habitat area at the site is not highlighted as a key core area in the plan. This plan has no regulatory authority. Field survey data, particularly Sage-Grouse surveys can be used to refine boundaries of habitat where fragmentation is an issue.
3.3.2 Shrub/Scrub and Grassland Bird Habitat Grassland bird species are generally on the decline nationwide, and many shrub/scrub nesting birds are declining as well. In large part this may be due to habitat destruction—less than 4% of the nation’s tallgrass prairies remain intact, for example. The largest threat to grassland habitat is changes in agriculture, including intensification, earlier haying times, and farm abandonment which leads to forest succession. In addition, many grassland and shrub/scrub bird species appear to avoid tall structures such as utility towers. This habitat effect is called avoidance. Wind turbines, utility towers, and similar structure may lower a bird’s perception of habitat quality, resulting in lower bird densities and reduced breeding output. The shrub/scrub and grassland habitat of the site can support many of the rare species being tracked. Grassland species include Grasshopper Sparrow, McCowan’s Longspur, Chestnut-collared Longspur, Loggerhead Shrike, Baird’s Sparrow, and White-tailed Prairie Dog. Shrub/scrub species include Sage Sparrow, Brewer’s Sparrow, Greater Sage-Grouse, Mountain Plover, and Wyoming Ground Squirrel. These species may be susceptible to habitat fragmentation and avoid tall structures. The small mammals mentioned may experience predation if transmission wires are not buried and may avoid developed areas and roads. Because dense grassland habitat is so rare at the site and is likely habitat for several area sensitive breeding birds, this habitat is of particular concern.
3.3.3 Riparian and Wetland Bird Habitat The habitat along Seven-mile and Spring Creeks contains a variety of wetland and riparian woodland habitat. This habitat is likely to be important for migrating passerine species and bats. Several species in decline regionally use wetlands (Appendix 5). Because riparian areas and wetlands are important biologically and comprise a small percentage of the site, they are of particular concern. The Wheatland Reservoir supports several species that are rare in Wyoming and declining in the ecoregion. It is the most significant aquatic feature near the wind farm. Field surveys should help determine the necessary setback from the reservoir and associated wetlands.
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4. RECOMMENDATIONS 4.1 Avoidance of Impacts The location of the wind turbines can have substantial effects on level of risk to wildlife. In general, several impacts will be reduced if: 1) Wind turbines should be located away from riparian habitat, wetlands, and grasslands. When possible, turbines should be placed in disturbed and developed areas, agricultural areas, and similar places. 2) Greater Sage-Grouse leks should be identified and avoided. 3) Proposed tower locations should be surveyed for prairie dog colonies, and if colonies are present proposed tower locations should be relocated 200m away from colony. 4) Towers should be set back from the Wheatland No. 3 Reservoir and associated wetlands. 5) Results of biological surveys should be used to aid in siting wind turbines. These recommendations are summarized in map form (Appendix 7, Sensitive Areas Map). 4.2 Minimization of Impacts The overall design of the wind farm can reduce wildlife impacts.
4.2.1 Turbine Array Layout Turbines should be placed singly or in groups rather than in rows to avoid blocking wildlife movement. Alignment of rows should be determined on the basis of wildlife movements. Migrants of all types are most likely flying southeastward in the fall and a northwest in the spring. Birds may view dense turbine rows on an east-west axis (perpendicular to their general migration route) as a barrier to migration. However, there is variability in flight direction among species and the migration direction varies with wind direction. Placing turbine groups with 1,000-1,500 ft between the groups will provide visually-oriented birds with a flight corridor through the wind farm. Grouping turbines can minimize other impacts by reducing the overall wind farm footprint.
4.2.2 Site Infrastructure Minimize fences, power lines, and other infrastructure. Many birds, particularly raptors and gamebirds, are killed by flying into powerlines, fences and guywires. Minimizing the use of these in the project vicinity can reduce the number of birds killed. Painting towers with non-reflective paint makes them more visible, presumably aiding birds seeking to avoid the turbines when in flight. Transmission lines should be buried to avoid increased predation on small mammals. Road lengths should be minimized wherever possible and placed perpendicular to habitat gradients (e.g., from stream to riparian zone to upland, not between the riparian zone and upland).
4.2.3 Land Cover Management Some authorities recommend that land cover be manipulated to reduce impacts to wildlife. For example, converting grassland to row crops or pasture reduces habitat quality and bird use. We disagree, believing that habitat loss is more significant an impact than mortality from collisions. It is our view that the small number of birds killed by wind turbines is insignificant in relation to the population level effects of lost habitat. For species which avoid wind turbines by large distances, it is best to avoid placing turbines within their habitat. For those species unavoidably impacted by wind turbines, mitigation in the form of habitat protection or construction provides the greatest level of protection for populations.
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4.3 Mitigation of Impacts In wind farm permitting, mitigation is generally not required prior to construction. If impacts to legally protected species are expected, an incidental take permit is usually issued in advance of construction. Pre- and post-construction monitoring is put in place and an action plan developed to deal with higher than expected mortality, should that occur. 4.4 Pre- and Post-Construction Monitoring Pre-construction field surveys help in micro-siting of turbines to avoid impacts to bird species of concern, high-use and species concentration areas, and important bird habitats. Pre-construction surveys also establish a biological baseline and allow correlations to be made between population level, mortality risk, and location. We recommend that at least one year of general bird surveys be done in spring and fall migration, and during the breeding season. In addition, surveys for individual species and species groups (e.g., raptors) are often needed. At this site, Sage-Grouse surveys are expected by the Wyoming Game and Fish Department. No protected bats occur in the area and no information exists to indicate that bats will be at significant risk at this site. Pre-construction bat surveys help confirm the species present at the site, their abundance, and areas of concentration. We recommend acoustic surveys be completed in the August-September period when resident bats are active and forest bat migration is at a peak. Bird and bat studies are timed to occur at the peak activity period for a group. Even though individual bird and bat species vary in their peak migration time, a survey spanning several days in a single week establishes the pattern of location and habitat use during migration. Earlier and later migrants use the same habitat. Some states are requiring that migration surveys be conducted each week for the entire migratory period. In our experience this does not improve the quality of data or certainty in identifying locations and habitats that are important to migrants. Survey times need to be flexible to fit with variable weather and migration events. Some states are requiring that post-construction monitoring be conducted for 1-3 years, depending on wind farm location and the species that are at risk. Monitoring consists of bird and bat surveys as described above, as well as mortality surveys that document the number of birds and bats actually killed. At this time we do not anticipate the need for post-construction surveys.
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5. LITERATURE CITED The Air Force and the National Fish and Wildlife Foundation. No date. Warren Air Force Base, checklist of birds. The Air Force and the National Fish and Wildlife Foundation. Unpaginated. Jamestown, ND: Northern Prairie Wildlife Research Center Online. . (Version 18SEP00) Accessed at http://www.npwrc.usgs.gov/resource/birds/chekbird/r6/warren.htm Arnett, E.B., W.K. Brown, W.P. Erickson, J.K. Fiedler, B.L. Hamilton, T.H. Henry, A. Jain, G.D. Johnson, J. Kerns, R.R. Koford, C.P. Nicholson, T.J. O’Connell, M.D. Piorkowski, R.D. Tankersley Jr. 2008. Patterns of Bat Fatalities at Wind Energy Facilities in North America. Journal of Wildlife Management 72(1):61-78. Arnett, E.B., ed. 2005. Relationship between bats and wind turbines in Pennsylvania and West Virginia: an assessment of fatality search protocols, patterns of fatality, and behavioral interactions with wind turbines. Unpublished report, Bats and Wind Energy Cooperative, Bat Conservation International. Austin, Texas, 187 pp. Baerwald, E.F., G.H. D’Amours, B.J. Klug, and R.M.R. Barclay. 2008. Barotrauma is a significant cause of bat fatalities at wind turbines. Current Biology 2008(18):695-696. Bat Conservation International. 2009. White-nose syndrome: the threat grows. http://www.batcon.org/index.php/do-something/stay-informed/white-nose- syndrome/subcategory.html?layout=subcategory (accessed 04/13/2009). Bat Conservation International. Species and profiles. http://www.batcon.org/index.php/education/article-and-information/species- profiles.html (accessed 04/2009). Carter, T. D. 1950. On the migration of the red bat, Lasiurus borealis borealis. Journal of Mammalogy 31:349-350. Chapman, S.S., Bryce, S.A., Omernik, J.M., Despain, D.G., ZumBerge, J., and Conrad, M., 2004, Ecoregions of Wyoming (color poster with map, descriptive text, summary tables, and photographs): Reston, Virginia, U.S. Geological Survey (map scale 1:1,400,000). Accessed at http://www.epa.gov/wed/pages/ecoregions/wy_eco.htm#Ecoregions%20denote 4/20/2009. Cryan, P.M. 2008. Mating behavior as a possible cause of bat fatalities at wind turbines. Journal of Wildlife Management 72(3):845-849. Cryan, P. M. 2003. Seasonal distribution of migratory tree bats (Lasiurus and Lasionycteris) in North America. Journal of Mammalogy 84:579-593. Cryan, P. M., and J. P. Veilleux. In press. Migration and the use of autumn, winter, and spring roosts by forest bats. In Bats in forests: conservation and management (M. J. Lacki, J. P. Hayes, and A. Kurta, eds.). Johns Hopkins University Press, Baltimore, Maryland. De Lucas, M. G., F. E. Janss and M. Ferrer. 2004. The Effects of a Wind Farm on Birds in a Migration Point: The Strait of Gibraltar. Biodiversity and Conservation, 13: 395-407. Furlonger, C. L., H. J. Dewar, and M. B. Fenton. 1987. Habitat use by foraging insectivorous bats. Canadian Journal of Zoology 65:284-288. Griffin, D.R. and D. Thompson 1982. High altitude echolocation of insects by bats. Behavioral Ecology and Sociobiology, Springer Hall, E. R. 1946. Mammals of Nevada. University of California Press, Berkeley, 710p.
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Hall, J. S. 1962. A life history and taxonomic study of the Indiana bat, Myotis sodalis. Reading Public Museum and Art Gallery, Scientific Publications 12:1-68. Hester, S. and M. Grenier. 2005. A conservation plan for bats in Wyoming. Wyoming Game and Fish Department, Nongame Program, Lander, WY. Horn, J.W., E.B. Arnett, T.H. Kunz. 2008. Behavioral responses of bats to operating wind turbines. Journal of Wildlife Management 72(1):123-132. Jackson, H. H. T. 1961. Mammals of Wisconsin. University of Wisconsin Press, Madison. 504p. Johnson, G. D. 2005. A Review of Bat Mortality at Wind-energy Developments in the United States. Bat Research News, 46: No. 2: 45-49. Johnson, G.D, W.P. Erickson, M.D. Strickland, M.F. Shepherd, D.A. Shepherd. 2000a. Avian monitoring at the Buffalo Ridge, Minnesota Wind Resource Area: Results of a 4-year Study. Western EcoSystems Technology, Inc. Cheyenne, Wyoming. Johnson, G.D., D.P. Young Jr., W.P. Erickson, C.E. Derby, M.D. Strickland, and R.E. Good. 2000b. Wildlife monitoring studies Seawest Windpower Project, Carbon County, Wyoming 1995-1999. Western EcoSystems Technology Inc. Cheyenne, Wyoming. Available online at: http://www.west-inc.com/reports/fcr_final_baseline.pdf. Jones, A., J. Catlin, T. Lind, J. Freilich, K. Robinson, L. Flaherty, E. Molvar, J., Kessler, and K. Daly. 2004. Heart of the West conservation plan. Salt Lake City, UT: Wild Utah Project, 180 pp. Available online at http://www.voiceforthewild.org/Heart_of_the_West/HeartoftheWestPlan.pdf. Kerlinger, Paul. How Birds Migrate. 1995. Stackpole Books. Mechanicsburg PA. Kingsley, A. and B. Whittam. 2003 .Wind Turbines and birds: a guidance document for environmental assessment. Prepared for Canadian Wildlife Service, Environment Canada. 351 St. Joseph Boulevard. • Gatineau, Quebec Kurta, A. 1995. Mammals of the Great Lakes Region. University of Michigan Press, Ann Arbor, 272 pp. Kurta, A., L. Winhold, J. O. Whitaker, Jr., and R. Foster. In press. Range expansion and changing abundance of the eastern pipistrelle (Chiroptera: Vespertilionidae) in the central Great Lakes region. American Midland Naturalist. Larkin, R. P. 2006. Migrating bats interacting with wind turbines: what birds can tell us. Bat Research News 47:23-32. Leddy, K. L., K. F. Higgins and D. E. Naugle. 1999. Effects of Wind Turbines on Upland Nesting Birds in Conservation Reserve Program Grasslands. Wilson Bulletin, 111(1): 100-104. Manville, A.M., II. 2004. Prairie grouse leks and wind turbines: U.S. Fish and Wildlife Service justification for a 5-mile buffer from leks; additional grassland songbird recommendations. Division of Migratory Bird Management, USFWS, Arlington, VA, peer-reviewed briefing paper. 17 pp. Molvar, E.M. 2008. Wind power in Wyoming: doing it smart from the start. Laramie, WY: Biodiversity Conservation Alliance, 55 pp. Available online at www.voiceforthewild.org/blm/pubs/WindPowerReport.pdf Mumford, R. E., and J. O. Whitaker, Jr. 1982. Mammals of Indiana. Indiana University Press, Bloomington. 537pp. Murray, S. W., and A. Kurta. 2004. Nocturnal activity of the endangered Indiana bat (Myotis sodalis). Journal of Zoology, London 262:197-206.
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National Research Council of the National Academies (NRCNA). 2007. Environmental Impacts of Wind Energy Projects. The National Academies Press, Washington, D.C. (Accessed 4/09 at http://www.nap.edu/catalog.php?record_id=11935). National Wind Coordinating Committee (NWCC) 2004. Wind Turbine interactions with Birds and Bats: A Summary of Research Results and Remaining Questions. Fact Sheet, Second Edition. Resolve Inc. Washington DC. http://www.nationalwind.org/publications/wildlife/wildlife_factsheet.pdf (accessed 11/2006) NatureServe. 2009. NatureServe Explorer: An online encyclopedia of life [web application]. Version 7.0. NatureServe, Arlington, Virginia. Available http://www.natureserve.org/explorer. (Accessed: April, 2009). Osborn, R. G., C. D. Dieter, K. F. Higgins and R. E. Usgaard. 1998. Bird Flight Characteristics Near Wind Turbines in Minnesota. American Midland Naturalist, Vol. 139, No. 1: 29-38. Osborn, R. G., K. F. Higgins, R. E. Usgaard, C. D. Dieter and R. D. Neiger. 2000. Bird Mortality Associated with Wind Turbines at the Buffalo Ridge Wind Resource Area, Minnesota. American Midland Naturalist, Vol. 143, No.1: 41-52. O'Shea, T.J., and Bogan, M.A., eds., 2003, Monitoring trends in bat populations of the United States and territories: problems and prospects. U.S. Geological Survey, Biological Resources Discipline, Information and Technology Report, USGS/BRD/ITR-2003-0003:1-274. Peurach, S. C. 2003. High-altitude collision between an airplane and hoary bat, Lasiurus cinereus. Bat Research News 44:2-3. Smallwood K.S. and Thelander C. 2008. Bird mortality in the Altamont Pass Wind Resource Area, California. Journal of Wildlife Management 72(1):215-223. Thomas, O. 1921. Bats on migration. Journal of Mammalogy 2:167. Verboom B. and H. Huitema. 1997. The importance of linear landscape elements for the pipistrelle Pipistrellus pipistrellus and the serotine bat Eptesicus serotinus. Landscape Ecology 12:117- 125. Wyoming Natural Diversity Database. 2009. Data compilation for H. Kieweg, completed February 20, 2009. Unpublished report. Wyoming Natural Diversity Database, University of Wyoming, Laramie, Wyoming. Zinn, T. L., and W. W. Baker. 1979. Seasonal migration of the hoary bat, Lasiurus cinereus, through Florida. Journal of Mammalogy 60:634-635.
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APPENDIX 1. SITE LOCATION
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APPENDIX 2. GAME & FISH - BIG GAME AND SAGE-GROUSE HABITAT AREAS
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APPENDIX 3. SITE HABITATS
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APPENDIX 4. LAND OWNERSHIP
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APPENDIX 5. WARREN AIR FORCE BASE BIRD SPECIES CHECKLIST & REGION 16 WYOMING BASIN BBS DATA
GROUP & SPECIES Abundance By Month1 BBS Trend 1980- 2007(%/yr)2 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec LOONS AND GREBES Common Loon ------443 334 ------4 433 344 4-- -1.8* Pied-billed Grebe ------4 433 333 333 333 333 333 333 444 --- -20.5 Eared Grebe ------432 222 222 222 222 222 222 333 --- 9.7 Horned Grebe --- --4 444 433 344 ------4 444 333 444 --- 3* Western Grebe ------443 444 ------4 433 334 -44 2.5 Clark's Grebe ------4 333 -44 ------44 334 ------2.5 PELICANS AND CORMORANTS American White Pelican ------444 333 444 444 444 333 444 -44 --- 4.4 Double-crested Cormorant ------4 433 334 444 444 444 333 444 -44 --- -5.6 BITTERNS AND HERONS American Bittern ------43 334 444 444 444 444 344 ------8.7 Great Blue Heron ------444 333 333 333 333 333 333 333 444 --- -1.4 Snowy Egret ------4 333 444 444 443 334 ------0* Cattle Egret ------444 4------444 444 -44 --- 2.2* Black-crowned Night Heron ------43 333 333 333 333 334 -44 ------2.5* IBISES White-faced Ibis ------4 333 4------44 444 -44 ------1.3* SWANS, GEESE AND DUCKS Tundra Swan ------444 ------4 444 ---
1 1 – Abundant, 2 – Common, 3 – Uncommon, 4 – Rare, 5 – Irregular, 6 – Accidental
2 Region 86 Wyoming Basin BBS Data. * denotes FWS Region 6 BBS Data. Bold indicates data significant at P<.2.
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GROUP & SPECIES Abundance By Month1 BBS Trend 1980- 2007(%/yr)2 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Greater White-fronted Goose ------6 666 666 ------666 666 666 --- Snow Goose --- --4 444 444 444 ------4 444 444 -44 --- Ross' Goose ------666 666 ------6 666 6-- Canada Goose 111 111 111 111 111 111 111 111 111 111 111 111 1.3 Wood Duck ------433 334 444 444 444 443 334 ------3.2* Green-winged Teal 333 333 333 222 444 444 444 444 432 223 333 333 12.8 Mallard 111 111 111 111 111 111 111 111 111 111 111 111 -1.9 Northern Pintail 444 444 443 111 223 333 333 333 333 322 234 444 4.3 Blue-winged Teal ------432 223 333 333 333 322 344 ------33.4 Cinnamon Teal ------333 444 444 444 444 433 4------3.7 Northern Shoveler ------444 333 444 444 444 444 433 344 444 4-- -13 Gadwall 444 444 443 222 333 333 333 333 333 222 344 444 5.7 American Wigeon 444 444 443 222 333 333 333 333 333 322 234 444 -3.5 Canvasback ------44 333 444 444 444 444 444 433 344 --- -7.2 Redhead 444 444 442 112 224 444 444 444 444 444 323 444 12.2 Ring-necked Duck ------444 333 444 444 444 444 444 433 344 --- 7.9* Lesser Scaup 444 444 321 112 223 444 444 444 444 322 234 444 -19.8 Common Goldeneye 444 444 444 333 444 444 444 444 444 444 333 444 4.6* Barrow's Goldeneye 666 666 666 444 466 666 666 666 666 664 444 466 -4.9* Bufflehead 444 444 444 433 334 444 444 444 444 443 334 444 14.9* Hooded Merganser 444 444 444 444 444 ------444 444 444 444 21.2* Common Merganser 444 444 443 222 334 444 444 444 444 333 444 444 -10.5 Red-breasted Merganser ------44 444 -44 ------4 444 4-- Ruddy Duck --- --4 444 333 444 444 444 444 444 333 444 4-- 1.9 AMERICAN VULTURES Turkey Vulture ------4 333 344 444 444 444 333 444 -44 --- 37.4 KITES, EAGLES, HAWKS AND ALLIES Osprey ------4 444 444 ------4 444 444 444 --- 42.8
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GROUP & SPECIES Abundance By Month1 BBS Trend 1980- 2007(%/yr)2 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Bald Eagle 444 444 444 444 4------44 444 444 15.3 Northern Harrier 444 444 444 443 333 333 333 333 333 344 444 444 7.3 Sharp-shinned Hawk 444 444 444 444 444 444 444 444 444 444 444 444 2* Cooper's Hawk 444 444 444 444 444 444 444 444 444 444 444 444 9.4* Goshawk 555 555 555 555 ------555 555 Swainson's Hawk ------443 222 222 222 222 333 334 ------7 Red-tailed Hawk 444 444 443 222 333 333 333 333 322 223 444 444 1.8 Ferruginous Hawk 444 444 444 333 333 333 333 333 333 334 444 444 -2.9 Rough-legged Hawk 333 333 333 334 -44 ------444 433 333 333 Golden Eagle 444 444 444 444 444 444 444 444 444 444 444 444 6.3 FALCONS American Kestrel 444 444 444 432 222 222 222 222 222 344 444 444 0.6 Merlin 444 444 444 444 666 666 666 666 666 444 444 444 12* Peregrine Falcon 666 666 666 444 666 666 666 666 444 666 666 666 -2.9* Prairie Falcon 444 444 443 344 444 444 444 433 334 444 444 444 9.2 PARTRIDGES AND GROUSE Ring-necked Pheasant 666 666 666 666 666 666 666 666 666 666 666 666 1.9 Sharp-tailed Grouse 444 444 444 444 444 444 444 444 444 444 444 444 1.3* Virginia Rail ------444 444 444 444 444 444 ------0.6* Sora ------4 333 333 333 333 444 -44 ------19.7 American Coot 444 444 433 222 222 222 222 222 222 222 233 444 -13.2 CRANES Sandhill Crane ------44 444 ------4 444 4-- --- 1.9 PLOVERS Black-bellied Plover ------4 444 ------444 444 444 ------Semipalmated Plover ------4 444 --- -44 444 444 -44 ------Killdeer ------44 222 222 222 222 222 222 224 -44 --- -1.9 AVOCET
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GROUP & SPECIES Abundance By Month1 BBS Trend 1980- 2007(%/yr)2 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec American Avocet ------4 443 334 444 444 444 334 ------19.4 SANDPIPERS, PHALAROPES AND ALLIES Greater Yellowlegs ------4 333 334 --- 444 443 333 344 ------Lesser Yellowlegs ------44 334 --- 444 444 333 -44 ------Solitary Sandpiper ------4 -44 --4 444 444 444 -44 ------Willet ------44 444 444 444 444 444 ------0.8 Spotted Sandpiper ------433 222 222 222 222 333 334 ------0.8 Upland Sandpiper ------444 444 444 444 444 ------0.7* Long-billed Curlew ------444 444 444 444 444 444 ------12.9 Marbled Godwit ------4 444 4-- --4 444 444 444 ------1.2* Semipalmated Sandpiper ------4 334 444 --- 433 444 ------Western Sandpiper ------4 444 444 --4 444 444 -44 ------Least Sandpiper ------44 333 444 --4 433 334 444 ------Baird's Sandpiper ------4 443 223 --4 443 222 344 444 ------Pectoral Sandpiper ------44 444 --- -44 444 444 444 ------Stilt Sandpiper ------6 ------Long-billed Dowitcher ------44 -34 --4 444 444 333 444 ------Common Snipe 444 444 444 333 333 333 333 333 333 444 444 444 2.3 Wilson's Phalarope ------444 322 333 333 222 334 444 ------4.3 GULLS AND TERNS Franklin's Gull ------433 344 444 444 333 444 4-- --- 357.2 Bonaparte's Gull ------6------Ring-billed Gull ------4 333 444 444 444 444 333 -34 ------21 California Gull ------4 322 333 333 333 333 222 334 ------3.4 Herring Gull ------44 444 444 444 444 444 444 444 444 -44 Caspian Tern ------44 444 444 444 444 444 444 -44 --- Common Tern ------66 666 666 666 666 666 6------3.6* Forster's Tern ------4 222 444 444 422 244 4------14.3
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GROUP & SPECIES Abundance By Month1 BBS Trend 1980- 2007(%/yr)2 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Black Tern ------442 224 443 333 344 ------5.5* DOVES Rock Dove 111 111 111 111 !11 111 111 111 111 111 111 111 -3.3 Mourning Dove ------433 322 222 222 222 222 444 ------1.4 OWLS Barn Owl ------44 444 444 444 444 444 444 ------Great Horned Owl 333 333 333 333 333 333 333 333 333 333 333 333 -11.6 Burrowing Owl ------4 333 333 333 333 333 333 334 4------14.1 Long-eared Owl 666 666 666 666 666 666 666 666 666 666 666 666 Short-eared Owl 666 666 666 666 666 666 666 666 666 666 666 666 -3.3* Northern Saw-whet Owl 666 666 666 666 666 666 666 666 666 666 666 666 GOATSUCKERS Common Nighthawk ------443 222 222 221 344 4------1.4 Common Poorwill ------433 333 333 333 333 ------48.1 SWIFTS Chimney Swift ------4 444 444 444 444 4------2.9* HUMMINGBIRDS Broad-tailed Hummingbird ------422 222 222 222 -24 ------6.3 Rufous Hummingbird ------4 444 333 -34 ------15.4* KINGFISHERS Belted Kingfisher 444 444 444 333 444 444 444 444 333 333 444 444 12.9 WOODPECKERS Lewis' Woodpecker ------444 444 444 443 334 ------0.4* Red-headed Woodpecker ------433 333 333 333 334 ------2.3* Red-naped Sapsucker ------4 444 444 ------444 444 4-- --- 20.3 Downy Woodpecker 333 333 333 333 333 333 333 333 333 333 333 333 -41.2 Hairy Woodpecker 444 444 444 444 444 444 444 444 444 444 444 444 Northern Flicker 333 333 333 333 333 333 333 333 333 333 333 333 1.7
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GROUP & SPECIES Abundance By Month1 BBS Trend 1980- 2007(%/yr)2 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec TYRANT FLYCATCHERS Western Wood-Pewee ------433 333 333 333 334 ------11.9 Willow Flycatcher ------444 444 444 444 -44 ------7.2 Least Flycatcher ------444 444 444 444 444 ------10.6 Say's Phoebe ------444 333 333 333 333 334 -44 ------3.6 Cassin's Kingbird ------6------Western Kingbird ------422 222 222 222 224 ------6.9 Eastern Kingbird ------444 333 333 333 333 444 ------1.5 LARKS Horned Lark 222 222 111 222 222 222 222 222 222 111 222 222 -1.2 SWALLOWS Tree Swallow ------4 444 444 444 444 444 444 ------6.7 Violet-green Swallow ------444 444 4-- --- 444 -44 ------8.9 Northern Rough-winged ------4 322 222 222 223 -44 ------19.8 Swallow Bank Swallow ------4 322 222 222 223 4------1.7 Cliff Swallow ------4 211 111 111 112 -44 ------0.9 Barn Swallow ------443 222 222 222 222 223 4------0.8 JAYS, MAGPIES AND CROWS Blue Jay 333 333 333 333 333 333 333 333 333 333 333 333 -0.3* Pinyon Jay 666 666 666 666 666 666 666 666 666 666 666 666 -3.7 Black-billed Magpie 222 222 222 222 222 222 222 222 222 222 222 222 1.5 American Crow 333 333 333 333 333 333 333 333 333 333 333 333 7.7 Common Raven 444 444 444 444 444 444 444 444 444 444 444 444 10.6 TITMICE Black-capped Chickadee 444 444 444 444 444 444 444 444 444 444 444 444 -6.6 Mountain Chickadee 333 333 333 333 333 333 333 333 333 333 333 333 -6.7 NUTHATCHES Red-breasted Nuthatch 333 333 333 333 333 333 333 333 333 333 333 333 -0.5*
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GROUP & SPECIES Abundance By Month1 BBS Trend 1980- 2007(%/yr)2 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec White-breasted Nuthatch 444 444 444 444 444 444 444 444 444 444 444 444 4.2* CREEPERS Brown Creeper 333 333 333 333 ------33 333 333 333 7.8* WRENS Rock Wren ------4 444 444 444 --- --4 444 444 -44 --- -0.4 House Wren ------444 422 222 222 222 224 444 444 --- 1.4 Marsh Wren ------44 222 222 222 222 444 -44 ------3.9 American Dipper 666 666 666 666 666 666 666 666 666 666 666 666 0.8* KINGLETS, BLUEBIRDS AND THRUSHES Golden-crowned Kinglet 333 333 333 333 -34 ------43 333 333 333 -7.8* Ruby-crowned Kinglet ------4 444 333 444 444 444 433 344 -44 --- 12.1 Blue-gray Gnatcatcher ------44 -44 ------4 444 -44 ------10.1 Eastern Bluebird ------6------6.3* Mountain Bluebird --- -44 322 223 344 444 444 444 322 233 444 --- -2.6 Townsend's Solitaire 222 222 222 223 334 ------433 332 222 222 0.1* Swainson's Thrush ------424 ------433 ------0.2* Hermit Thrush ------4 334 ------443 444 -44 --- -0.6* American Robin 333 333 333 111 222 222 222 222 211 122 333 333 -0.1 THRASHERS AND ALLIES Gray Catbird ------44 333 333 333 333 333 444 444 --- 19.7 Northern Mockingbird ------4 444 444 444 444 444 444 444 --- 2.2* Sage Thrasher ------44 444 444 ------4 444 -44 ------1.3 Brown Thrasher ------4 433 444 444 444 443 333 -34 ------1.5* PIPITS AND WAXWINGS American Pipit ------4 444 444 ------4 444 444 --- Bohemian Waxwing 555 555 555 555 ------5 555 555 555 Cedar Waxwing 444 444 444 444 433 444 444 444 444 333 444 444 -18.5 Northern Shrike 444 444 444 -44 ------4 444 444 444 444
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GROUP & SPECIES Abundance By Month1 BBS Trend 1980- 2007(%/yr)2 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Loggerhead Shrike ------444 444 444 444 444 444 444 -44 --- 9.6 European Starling 111 111 111 111 111 111 111 111 111 111 111 111 0.4 VIREOS Plumbeous Vireo ------44 4------4 444 4------0.9* Warbling Vireo ------442 444 444 444 224 444 ------6.1 Red-eyed Vireo ------44 ------444 444 ------6.1* WOOD-WARBLERS Orange-crowned Warbler ------4 434 ------4 434 444 ------12.6 Virginia's Warbler ------444 ------4 -44 ------1.5* Northern Parula ------444 -44 ------6.2* Yellow Warbler ------4 322 222 222 222 234 -44 ------3.7 Yellow-rumped Warbler ------4 444 222 ------4 222 233 444 --- 4.4 Townsend's Warbler ------44 ------334 444 444 --- -0.5* Blackpoll Warbler ------44 ------4 444 ------American Redstart ------4 444 ------4 444 ------25.9 Ovenbird ------44 ------4 444 -44 ------0.7* Northern Waterthrush ------444 ------4 -44 ------1.5* MacGillivray's Warbler ------433 444 444 444 433 4------6.1 Common Yellowthroat ------433 333 333 333 334 ------0.2 Wilson's Warbler ------322 4------4 222 344 ------8.6 Yellow-breasted Chat ------4 444 ------4 444 ------8.1 TANAGERS Western Tanager ------4 434 ------4 444 -44 ------25.3 CARDINALS, GROSBEAKS AND ALLIES Black-headed Grosbeak ------4 434 444 444 444 344 4------10.6 Blue Grosbeak ------44 444 444 444 -44 ------2* Lazuli Bunting ------4 433 333 333 333 344 -44 ------7.7 Dickcissel ------666 666 666 666 6------0.3*
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GROUP & SPECIES Abundance By Month1 BBS Trend 1980- 2007(%/yr)2 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec TOWHEES AND SPARROWS Green-tailed Towhee ------4 444 333 333 333 333 344 444 ------1.9 Spotted Towhee ------4 444 334 444 444 444 334 444 444 4-- 16.4 American Tree Sparrow 333 333 333 344 ------4 443 333 333 Chipping Sparrow ------442 224 ------432 222 344 ------6.8 Clay-colored Sparrow ------44 334 ------4 334 -44 ------13.3 Brewer's Sparrow ------4 444 334 ------43 344 -44 ------0.4 Vesper Sparrow ------4 444 333 333 333 333 333 444 ------0.4 Lark Sparrow ------4 433 333 333 333 334 -44 ------0.1 Lark Bunting ------4 322 222 222 222 334 ------2.8 Savannah Sparrow ------43 333 333 333 333 333 444 -44 --- 2.9 Grasshopper Sparrow ------4 444 444 444 444 444 ------5.6 Song Sparrow 444 444 444 322 333 333 333 333 223 444 444 444 0.9 Lincoln's Sparrow ------4 444 333 4------4 333 -44 ------15.1 White-throated Sparrow ------666 666 ------666 666 666 666 White-crowned Sparrow 444 444 443 344 444 ------4 444 433 334 444 2.2 Harris' Sparrow 444 444 444 444 -44 ------4 444 444 444 Dark-eyed Junco 333 333 333 333 444 ------444 333 333 333 0.2 McCown's Longspur ------44 433 333 333 333 333 344 444 ------2.1 Lapland Longspur 444 444 444 4------44 444 444 Chestnut-collared Longspur ------44 444 444 444 444 444 ------4.8 Snow Bunting 444 444 444 -44 ------444 444 444 Bobolink ------4 444 ------4 444 4------2.7* BLACKBIRDS AND ORIOLES Red-winged Blackbird 333 333 333 321 111 111 111 111 111 122 333 333 0 Western Meadowlark ------44 333 222 222 222 222 222 334 ------1.2 Yellow-headed Blackbird ------43 222 222 222 222 233 -44 ------0.1 Brewer's Blackbird 444 444 444 443 222 222 222 222 333 444 444 444 0
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GROUP & SPECIES Abundance By Month1 BBS Trend 1980- 2007(%/yr)2 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Great-tailed Grackle (1st State ------6- 13 ------3.4* Record May ’89) Common Grackle 444 444 444 432 222 222 222 222 344 444 444 444 -3.3 Brown-headed Cowbird ------444 333 333 333 333 333 -44 ------4.3 Orchard Oriole ------44 444 444 -44 ------2.7* Bullock's Oriole ------4 333 333 333 333 -34 ------2.9 FINCHES Cassin's Finch 444 433 333 333 334 ------433 333 444 444 6.5 House Finch 222 222 222 222 222 222 222 222 222 222 222 222 4.9 Common Redpoll 444 444 444 444 -44 ------4 444 444 444 Pine Siskin 333 333 333 333 334 444 444 444 433 333 333 333 -15.2 American Goldfinch 444 444 444 444 333 333 333 333 334 444 444 444 -1 Evening Grosbeak 444 444 444 444 444 444 444 444 444 444 444 444 -18.4* OLD WORLD SPARROWS House Sparrow 111 111 111 111 111 111 111 111 111 111 111 111 -0.1
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APPENDIX 6. HEART OF THE WEST CONSERVATION PLAN
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APPENDIX 7. SENSITIVE AREA MAP
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