Conservation Status of Ochlodes Yuma Anasazi Cary and Stanford

Conservation Assessment of Ochlodes yuma anasazi (S. Cary and Stanford)

Final Report to New Mexico Department of Game and Fish pursuant to contract no. 11 516 0000 00025

Steven J. Cary, Linda S. DeLay and John J. Pfeil Natural Resource Institute Santa Fe, New Mexico

December 29, 2011

TABLE OF CONTENTS

page

Introduction ...... 3

Previous Work ...... 4

Study Area ...... 5

Methods ...... 8

Results ...... 10 Life History and Ecosystem Services . . . . . 10 Distribution of Host Reed...... 12 Breeding Distribution of OYA ...... 12 Population Structure of OYA ...... 15 Dispersal of OYA ...... 15

Vulnerability ...... 21

Threats ...... 21

Future Work ...... 25

Literature Cited ...... 27

Appendix A: Location of Reed Patches ...... 31

Appendix B: Adult OYA Observations ...... 36

Appendix C: Detailed Reed Patch Maps ...... 39

Acknowledgements The authors gratefully acknowledge the assistance of volunteers who made our jobs much easier. Randy Merker, Chuck Noble and Paige Prescott assisted with our float through the La Junta reach of the Rio Grande. Paige's sharp eye quickly spotted larval shelters in reed patches. Jane Pfeil provided excellent note-taking and admirable culinary support. Doug Bland and Eric Rounds provided welcome driving, navigation and photography support. Bureau of Land Management biologist Valerie Williams gave helpful comments on a working draft of this report.

Cover: Male Ochlodes yuma anasazi perching for females on Phragmites australis leaf at Little Arsenic Springs, August 26, 2011, by S. Cary.

2 Introduction Yuma skipper, Ochlodes yuma (W. H. Edwards 1873), is a 2.5cm-long butterfly (Figure 1) whose occurrence spans much of the American West and Southwest (Figure 2). Across this broad geographic range its habitats are defined by the presence of one plant species: common reed [= Phragmites australis (Cav.) Trin. ex Steud.]. In the semi-arid southwestern U. S. this obligate wetland plant is restricted to marshes, watercourses, pond edges, seeps, sloughs, springs and irrigation canals. Despite occurring in many western states, most populations are present only in narrow ribbons or pockets of habitat often separated from other populations by many miles of reed-less terrain (Scott et al. 1977). Colonies of O. yuma often seemed hosted by reed patches that seem quite small, sometimes only about 300 m2, and in one case only 5 m2 (Scott et al. 1977). Only rarely were adults found more than a few meters from stands of the host plant (Scott et al. 1977). Conservation organizations weighed O. yuma occurrence in most U. S. states west of the Rocky Mountains, concluded it is globally secure, and assigned it a Heritage Global Rank of G5 (www.natureserve.org/explorer).

Figure 1. Ventral view of Ochlodes yuma anasazi. Photo Aug. 14, 2009, by S. Cary.

At the perimeter of the overall range of O. yuma are several small satellite populations that appear to be geographically and reproductively disjunct from the general population center of the species in the Intermountain West. Outlier populations exist in Oregon, Washington, Wyoming and New Mexico (Figure 2). Those in Oregon and Washington were tentatively placed with Nevada subspecies O. y. lutea. Washington populations were assigned a state conservation rank of S1 (critically imperiled) (www.xerces.org/yuma-skipper/). Another outlier, O. y. anasazi (OYA), is restricted to northern New Mexico and the Rio Grande watershed. It was described as a distinct subspecies (Cary and Stanford 1995) and Pelham (2008) tacitly affirmed its phenotypic differentiation and genetic isolation from other O. yuma colonies. Due to lack of detailed published information about this subspecies, its conservation status has yet to be established (e.g., www.xerces.org/yuma-skipper/). The Share with Wildlife program of the New Mexico Department of Game and Fish funded this study to analyze its biology, habitat, distribution and threats and develop a conservation assessment.

3 Figure 2. County distribution of Ochlodes yuma (www.butterfliesandmoths.org/).

Previous Work Wheeler Expedition naturalist Ferdinand Bischoff made the first collection of Ochlodes yuma in 1871 in southern California (Brown 1957, Brown and Miller 1980). W. H. Edwards (1873) used those specimens to formally describe the species two years later. Skinner (1899) described Pamphila scudderi from western Colorado, but this taxon was later synonymized with O. yuma (Miller and Brown 1981). Information about O. yuma accumulated slowly (e.g., Tilden 1957). Its affinity to marshy habitats was recognized early (e.g., Brown et al. 1957), but its larval host plant remained unknown until 1974 when a female was observed placing an egg on a basal leaf of Phragmites australis (Scott et al. 1977, Scott 1992). The distribution of O. yuma was long thought to include only Arizona, California, Colorado, Nevada and Utah (e.g., Garth 1950, Ferris and Brown 1980). Some 20th Century Colorado workers (Scott et al. 1977) found “no geographic variation” across this broad western reach of O. yuma. Ferris and Brown (1980), however, were skeptical of this putative uniformity because modern populations seemed to have been “isolated from one another for thousands of years.” Understanding of the distribution of O. yuma has improved since 1980. Peripheral colonies were discovered in the states of Wyoming and Idaho (e.g., Stephens 2002), Oregon and Washington (Pyle 2002), and New Mexico (Cary and Stanford 1995). These discoveries demonstrated that O. yuma occurred beyond the boundaries of the Colorado River basin and the Intermountain West. Discernment of morphological differences within its far-flung range finally allowed Pelham (2008) to recognize the following distinct races of O. yuma:  the nominate race of O. y. yuma in southern California;  O. y. scudderi in western Colorado;  O. y. lutea in north-central Nevada and the Pacific Northwest (Austin 1998);  O. y. sacramentorum in California’s Central Valley (Austin 1998); and  O. y. anasazi in northern New Mexico (Cary and Stanford 1995). Nothing has been published about OYA since its original description. More than 30 years of detailed butterfly observations around New Mexico by the senior author produced no other O. yuma sightings. One anecdotal, unconfirmed report of O. yuma from near Shiprock in San Juan County, NM, is most likely western Colorado subspecies O. y. scudderi.

4 Study Area All known occurrences of OYA are associated with the Rio Grande Gorge, a major physiographic feature extending the length of Taos County in northern New Mexico (Figure 3).

Figure 3. Map of the Rio Grande Gorge study area in Taos County, NM.

5 Along that distance of more than 100km the Rio Grande has excavated a steep-walled canyon through thickly layered basalts and related sediments (Figure 4). The Gorge begins as a small notch near the Colorado state line, deepens to a defile more than 250m deep, then broadens into a flat-bottomed canyon north of Española. Over this distance the Rio Grande falls from 2267m above sea level at the Colorado border to 1790m above sea level at the Rio Arriba County line.

Figure 4. Rio Grande Gorge looking north from trail toward Big Arsenic Springs. S. Cary photo Aug. 26, 2011.

The Rio Grande Gorge is deeply incised into the Taos Plateau which, at 2287m elevation, occupies the valley between the Sangre de Cristo Mountains on the east and the Tusas Mountains on the west. Geologically this "low" spot is the southern portion of the San Luis Basin, which is the northernmost structural basin of the continent-scale Rio Grande Rift, which continues south into Texas and Mexico. The Taos Plateau represents the top of a 200 km3 layer-cake of basalts termed the Servilleta Formation. These basalts began as lava erupted from shield volcanoes that are still evident only a few kilometers to the west. As described by Bauer et al. (2007), these lavas flowed “as thin, molten sheets for tens of miles before solidifying.” Episodic eruptions between 4.8 and 2.8 million years ago built up more than 200m of basalt in this part of the San Luis Basin. Servilleta basalts are highly permeable as a result of extensive fractures and columnar joints that are open and vertically continuous, combined with deposits of sand and

6 gravel deposited between individual basalt flows (Bauer et al. 2007). Several Rift-related fault systems intersect the Gorge and are significant conduits for water movement (Bauer et al. 2007). By New Mexico standards, Taos County is rich in surface waters because it hosts the state’s highest upland, the Sangre de Cristo Mountains, a linear range which parallels the Gorge several miles to the east. These uplands generate orographic precipitation exceeding 50 cm/yr (e.g., www.wrcc.dri.edu/cgi-bin/cliMAIN.pl?nm7323), which in turn supports numerous perennial streams and rivers. Three of these are important tributaries to the Rio Grande in the study area: Red River, Rio Hondo and Rio Pueblo de Taos. As these and lesser watercourses exit the uplands and head west and southwest toward the Gorge, water infiltrates downward through the coarse sands and gravels of alluvial fans and foot slopes and into the highly fractured basalts below. Infiltrating waters recharge local groundwater, some of which discharges to the Rio Grande through more than 150 springs in the channel bottom, along channel banks, and from canyon walls as much as 120m above the river (Bauer 2011). Many of these springs are clustered where the Gorge cuts across major geologic faults (Bauer et al. 2007). Plant communities in the study area exhibit characteristics of an inverted ecosystem: mesic pine woodlands occur at lower elevations than semi-arid shrub-steppe, when the normal relationship is reversed. Vegetation on the Taos Plateau is semi-arid grassland and shrubland dominated by big sagebrush (Artemisia tridentata) mixed with soapweed yucca (Yucca glauca) and grasses including blue grama (Bouteloua gracilis). Among woody plants, piñon pine (Pinus edulis) and one-seeded juniper (Juniperus monosperma) are locally favored. Rabbitbrush (Chrysothamnus nauseosus), annual sunflower (Helianthus petiolaris), gumweed (Grindelia sp.) and poison milkweed (Asclepias subverticillata) have colonized disturbed areas. Between the Taos Plateau and the Gorge bottom, rugged slopes support a mosaic that includes ponderosa pine (Pinus ponderosa), three-leaf sumac (Rhus trilobata), chokecherry (Prunus virginiana), currants (Grossulariaceae), wild buckwheats (Eriogonum spp.), poison ivy (Toxicodendron radicans) and a variety of grasses (Poaceae). Riverbanks, seeps and springs support a diverse assemblage of wetland plants including Rio Grande cottonwood (Populus deltoides wislizeni), narrowleaf cottonwood (Populus angustifolia), coyote willow (Salix exigua), Virginia creeper (Parthenocissus quinquefolia), common reed (Phragmites australis), cattail (Typha sp.), dogbane (Apocynum sp.), and numerous sedges and grasses. Lands occupied by OYA are managed primarily by the U. S. Bureau of Land Management (BLM) through its Taos Field Office. Land and resource management activities on these public lands are governed by the 1988 Resource Management Plan, for which a revision is in preparation (USDI-BLM 2010). Some colonies of OYA may occur on adjacent lands governed by Taos Pueblo, which were not investigated as part of this study. Vehicle access to the study area is available at four principal locations. U.S. highway 64 traverses the Taos Plateau in a southeast-northwest direction and its Rio Grande Gorge Bridge provide visual access to the bottom of the Gorge. A second paved road, SR 387 leads southwest from Cerro and facilitates access to rim-top BLM recreation areas and to trails leading down into the Gorge. Auto access to the Gorge bottom is available via two maintained gravel roads: SR 570/567 crosses at Taos Junction Bridge north of Pilar and County Road B007 crosses at John Dunn Bridge west of Arroyo Hondo. Miles of jeep roads lead to or parallel the rim on east and west sides; they are seasonally closed and not regularly maintained. They function well when dry, but may present a marginal ratio of opportunity to risk when wet.

7 Methods One primary objective of this study was to define the occurrence of OYA in the Gorge in greater detail. The best way to find O. yuma is to locate and examine stands of the reed upon which the butterfly is completely dependent, an approach used with success elsewhere (e.g., Stephens 2002). The task of locating reed stands was simplified by prior efforts of Bauer et al. (2007) and Bauer (2011), who mapped springs in the Gorge and, in so doing, mapped potential habitat for reed and for OYA. In the field we used several methods to map reed occurrences (Figure 5). South of Taos Junction Bridge, reeds could be mapped from paved roads along the

Figure 5. Vantage points from which reed patches were mapped.

8 river. Farther north, the most effective way to find reed patches was with binoculars from the Gorge rim. From key vantage points on the rim (Figure 5) we scanned east and west riverbanks and valley side-slopes for up to a mile at a time and in a matter of minutes recorded any reed patches we observed. Reeds observed in this manner were mapped using a rangefinder (Contour XLRic) linked to a Trimble GeoXT global positioning system (GPS). Reed patches assumed a variety of ill-defined shapes and characteristics that made them challenging to define, delineate and quantify. Any analyses we did based on reed patch data should be considered preliminary. Tasks of reaching and examining reed patches for evidence of OYA proved more challenging. Access by river craft, while conceptually appealing, usually proved impractical. For example, the entire Gorge above Little Arsenic Springs consists primarily of Class IV+ whitewater (Bauer 2011). Further, river craft are most functional during snowmelt runoff in May and June, but these are not advantageous times to look for OYA adults, which are most abundant in August when low river flow limits float options. Nevertheless, in July 2011 river craft were used to access the 8-mile segment of Gorge between Little Arsenic Springs and John Dunn Bridge, where several reed colonies were successfully mapped. From June through early November, reed patches were examined visually for evidence of OYA's distinctive larval feeding patterns and tubular larval shelters. Each larval shelter is evidence that a female placed an egg there the previous year and the offspring survived in the current year at least long enough to grow to a late-stage larva. All evidence obtained for OYA during the course of this study was mapped using one of the following cited GPS units. Given the time constraints of this study, along with the size and logistical challenges posed by the Gorge, not all reed patches have been identified, visited or inspected for evidence of OYA. Gorge access by foot from the Taos Plateau involved vertical journeys of up to 250m on trails varying from first-rate and well-maintained to primitive footpaths worn by wildlife or fishermen, some rated as "extremely difficult." Venturing off trails leads one to steep cliffs and extensive fields of loosely stacked basalt boulders ranging in size from living-room furniture to automobiles, with intervening crevices of comparable size and unknown depth. Due to difficulty crossing the Rio Grande, reed patches east and west sides of the river were accessed on foot from east and west sides of the Gorge respectively. We were slow and inefficient finding and examining reed patches while walking on the Gorge bottom where we lacked vertical perspective. Frequent topographic irregularities had to be circumnavigated because we could not see over or around them. Reed patches visited were mapped using either a Garmin GPSMAP 76CSx (median accuracy 3m), a Trimble GeoXT (median accuracy 1m), or a Trimble Juno SB (median accuracy 3m). Digital aerial photos (DOQQ 2005-6; NM RGIS Clearinghouse http://rgis.unm.edu/were used as a navigation tool and to adjust GIS locations of reed patches when needed. GIS data processing, mapping and analyses were accomplished with use of ArcGIS ArcInfo 9.3 (ESRI, Conservation Grant Program award, 2009). GPS post-processing was done with GPS Pathfinder Office (Trimble) and DNR Garmin (Minnesota Dep. Natural Resources) software. Distances less than the precision of GIS tools (ca. 5 m) were estimated visually. During the period when adults are in flight, late July to mid-September, OYA were observed and identified with unaided eyes or Eagle Optics Ranger 8x42 close-focus binoculars. In August 2011, adults were captured with aerial insect net, sexed, and then marked by cutting a small, harmless notch in the margin of the hindwings so we would know if we re-captured it.

9 Results

Sections below describe, analyze and discuss observations made during NRI's three years of field work, 2009 -2011.

Life History and Ecosystem Services The life history of OYA is substantially the same as for the species as a whole (e.g., Scott et al. 1977). Like its parent species, O. yuma anasazi requires common reed (= Phragmites australis) for its caterpillars to feed. Successful reproduction requires reed beds where females can place eggs. Common reed is a tall (to 4m), long-lived, perennial grass that forms cane-like thickets in wet places (http://plants.usda.gov/java/charProfile?symbol=PHAU7) (Figure 6). It tolerates salinity (e.g., Meyerson et al. 2000), but not shade. It has spreading rhizomes, wind- dispersed seeds, and is known from all continents except Antarctica. In western North America it inhabits river edges, irrigation ditch banks, freshwater springs, and even alkaline or sulfurous seeps (Scott et al. 1977). In New Mexico it forms thickets along streams and in wet ground of springs and seeps (Allred 1993). Paddlers and commercial boat guides working on the Rio Grande call it "river cane."

Figure 6. Stand of common reed in left foreground. S. Cary photo July 22, 2011.

10 OYA requires one year to complete its life cycle; most of that time is spent in immature stages (Figure 7). As a group, adults are in flight from late July to mid-September (Cary and Stanford 1995), but each individual adult only has about two weeks to find a mate and complete its life cycle. To locate females, males perch on leaves of the larval host (see cover photo) and fly out to investigate passing objects. Males chase away other males, but follow and court females, often tail-gating them in and out among reed stems. To maintain energy levels, adult OYA take nectar from nearby flowers such as thistle (Cirsium spp.) and taperleaf (Pericome caudata); they fly longer distances to reach rabbitbrush and milkweed.

Figure 7. Annual life cycle of Ochlodes yuma anasazi. Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Adult Pupa Late stage larva Young larva ? ? ? ? ? ? ? Ovum ? ? ? ? ? ? ?

After mating, females place eggs at the base of the host (Scott et al. 1977). It is not known when eggs hatch. They may hatch quickly, then enter diapause and pass the winter as first instar larvae; or they may enter diapause and overwinter as ova, then hatch in spring when young larvae have access to nutritious new shoots and leaves. Young larvae eat tissue of reed's long, lance-shaped leaves, often rolling leaf edges for shelter. Older larvae chew inward from both leaf margins toward the mid-vein, weakening the leaf until the distal end bends downward under its own weight, suspended by the mid-vein. The larva then silks together the two edges of the hanging leaf to fashion a cylindrical shelter (Figure 8A). Larvae exit shelters at night to feed, then return to rest and hide during daylight hours (Cary, pers. obs., 1985). Individuals pupate within leaf shelters by mid- or late-July.

Figure 8. (A.) OYA larva in shelter. (B.) Wasp patrolling reed stems. S. Cary photos July 22, 2011.

Lepidoptera generally perform three important ecosystem roles: they are herbivores, pollinators, and food items for predators. Herbivory occurs in a lepidopteran's larval stage and

11 the menu of suitable plants varies among different butterfly and moth species. Some consume members of multiple plant families; others are family specific herbivores; yet others are narrowed to a genus or a few species. A few are restricted to a single plant species and this is true for all geographic races of Ochlodes yuma, including OYA, whose larvae consume only Phragmites australis. For OYA, this degree of specificity may be linked to the fact that few native grasses offer suitable leaves for larvae to make shelters. Predation and parasitism also tend to occur primarily in a lepidopteran's larval stages, when they cannot flee. Larvae and pupae of O. yuma can be parasitized (e.g., Scott et al. 1977). In the Gorge, we found a variety of predatory hymenopterans patrolling reed beds, presumably in search of immature OYA (Figure 8B). Selective pressures associated with parasitism and predation are probably responsible for OYA adaptations such as nocturnal feeding and construction of shelters for larval repose and pupation. Much remains to be learned about OYA's food web linkages. The role of OYA adults as potential pollinators for flowering plants is only partially understood. The larger group of Hesperiine skippers, of which OYA is one species, typically has adults with long proboscides, a specialization that allows them to reach nectaries deep inside flowers with elongated corollas. One close cousin to OYA, Paratrytone snowi, is an important pollinator for one of New Mexico's rarest plants, Ipomopsis sanctu-spiritus (S. Cary, pers. obs.). This context may suggest that OYA may be an important pollinator for certain plants. To date, OYA adults are known to visit thistles, rabbitbrush, taperleaf and milkweed. The architecture of thistle and rabbitbrush flowers is such that OYA is likely to be an effective pollen vector. Two plant species visited by adults, Cirsium vulgare and Cirsium arvense, are noxious weeds.

Distribution of Host Reed Beds of common reed, which are restricted in their occurrence, define breeding habitat for OYA. During this project we geo-located and obtained GPS coordinates for 128 reed patches within the Rio Grande Gorge. Reed patch data are presented in Appendix A and mapped in Figure 9 and Appendix C. Patch size varied widely; some were a mere handful of stems, while others exceeded a hectare. River reaches with a high frequency of reed patches usually coincided with concentrations of seeps and springs, which reflect preferential underground water movement along geologic faults (Bauer et al. 2007). As examples, waters draining from Ute Mountain feed reed beds in the Sunshine Spring zone; Felsenmeere Springs and reed patches seem associated with the Red River fault zone; and the Dunn Fault steers water to reed patches at Black Rock Spring and Manby Hot Springs. The largest reed concentrations were observed near Big and Little Arsenic Springs (>6 ha), Lavatube Spring (>4 ha), and Chiflo Springs (>1 ha). Due to challenges in accessing the Gorge bottom and difficulties getting a clear, unobstructed view of the bottom from the rim, several reaches of the Gorge remain unmapped for reed patches (see Figure 5). Most unmapped sections are short. The longest unmapped reach extends from south of the US 64 Bridge to the Taos Junction Bridge, a distance of about 16km known to rafters as the Taos Box (Bauer 2011).

Breeding Distribution of Ochlodes yuma anasazi Published information regarding distribution of OYA has been limited to its initial description (Cary and Stanford 1995), which simply placed it in the Rio Grande Gorge near Questa, and our interim report (Cary et al. 2011). Field investigations completed as part of this present study now allow the distribution of OYA to be characterized in greater detail. After

12 considerable field hours in 2009, 2010 and 2011 examining P. australis patches and searching for adults, the breeding distribution of OYA is displayed in Figure 9. Expanded maps of reed patches and springs in key sections of the Gorge are provided in Appendix C. We also looked for adult OYA and found 99 individuals at 67 localities (Figure 10; Appendix B).

Figure 9. Reed beds exhibiting presence or absence of evidence of OYA reproduction.

13 Within the potential Rio Grande Gorge (RGG) breeding habitat for OYA, as defined by known reed patches, we looked for evidence that OYA was breeding or reproducing. We inspected as many reed beds as possible for signs that OYA larvae had chewed reed leaves or made tubular shelters. These investigations and observations were made during the months of July through November. We found positive evidence of OYA presence, breeding or

Figure 10. Locations of OYA adults observed during this study.

14 reproduction from north of Chiflo Spring south to Black Rock Spring just below John Dunn Bridge, and about 1.5km up the Red River. Comparison of Figures 9 and 10 shows that all OYA adults were found in the same reach of the Gorge as the reed patches exhibiting evidence of OYA immature stages. During this study, OYA occupied about 26km of Rio Grande Gorge. Frequent, large reed beds north of Chiflo and fewer, smaller reed beds south of Taos Junction Bridge showed no evidence of use by OYA during 2009-2011.

Population Structure of Ochlodes yuma anasazi Based on all observations to date, a basic population structure for OYA is taking shape. Patches of host reed are found intermittently throughout the Gorge from near Ute Mountain south beyond Pilar. In some reaches the reed beds are infrequent or small, but in other reaches they are frequent and large, often paralleling the frequency and size of springs in the Gorge (Bauer et al. 2007). One apparent nucleus of OYA distribution is the elaborate complexes of springs and seeps at Big Arsenic Springs on the east side of the river. About 2.5 mi upstream, Felsenmeere Springs on the west side of the river is known to be part of the "most volumetrically significant spring zone in the Gorge" (Bauer et al. 2007). This spring/seep complex was not examined for OYA, but it its reed stands are moderate in size and a colony of OYA is a virtual certainty. OYA has been found north to just above Chiflo Springs and south to just below John Dunn Bridge. Along the 26km reach between these northernmost and southernmost occurrences of OYA we found evidence of OYA occupation on nearly all of the reed patches we examined. Reed patches examined farther north and farther south showed no evidence of OYA. Not all reed beds were examined. Within its RGG range OYA appears to exist as a metapopulation, which is defined as a collection of smaller, discrete colonies which persist over time by maintaining a balance between extinction and re-establishment of component colonies. Harrison (1991) refined that classical view to delineate three different types of metapopulations found to exist in nature: (1) Mainland-island or source-sink populations have a single extinction-resistant population which sustains the metapopulation. (2) Patchy populations have high dispersal rates which allow the system to function as a single extinction-resistant population. (3) Non-equilibrium populations are those in which local extinctions occur as part of long- term decline of a species. If Big Arsenic Springs proves to be the primary population center for OYA, then OYA could be considered to have a mainland-island type of metapopulation. The source-sink description has a ring of truth because many smaller patches of reed far from Big Arsenic Springs showed too few larval shelters or pupae (<5) to maintain viable OYA colonies on their own. Instead, it seems more likely that passing females simply placed a few eggs there before moving on. On the other hand, no other reed patch in the Gorge has been studied for OYA occupancy as much as Big Arsenic Springs. If/when other extensive reed stands receive the same amount of study, OYA may prove to exhibit more of a type 2 metapopulation.

Dispersal of Ochlodes yuma anasazi Metapopulations persist only if gravid females can successfully disperse among different habitat patches to re-colonize patches where local colonies have been lost. Successful dispersal hinges on (a) the physical ability to fly required distances and (b) the behavioral motivation to make such flights. Evidence available prior to this present study suggested that O. yuma adults

15 rarely wander more than a few meters from stands of the host reed. Although O. yuma appears to be stout, well-muscled and capable flyer, its behavior seems to focus on locating mates within reed patches rather than long or wide-ranging flights. Scott et al. (1977) noted only one exception, to their knowledge, in which an individual was found 0.8 km from a reed patch. [Pyle (2002) found a colony in Washington on a clump of non-native Miscanthus sp. in a formal garden 250 km from the nearest known colony, but the meaning of this colony is unclear because it may have been transported to the site when the landscaping was installed.] Our working hypothesis regarding dispersal capability of OYA was that adult occurrence would be similar to what Scott et al. (1977) described for the species as a whole: adults would occur primarily near host reeds and the number of adults observed would decline rapidly with increasing distance from reeds. In studies of other rare butterflies this relationship has followed an inverse power function or a negative exponential function (e.g., Baguette et al. 2000). If y = number of adult OYA observed at distance x from reed, then a negative exponential function takes the form y = a-x and an inverse power function takes the form y = x-a or 1/xa; the rate at which OYA observations decline with increasing distance from reed would determine the value of "a." The distinction between the two mathematical forms is not important at this point; each can depict a rapid decline in butterfly abundance with increasing distance from the host. We tested our hypothesis in August 2011 by observing and geo-locating adults, then using GIS analytical tools to calculate their distances from the nearest reed beds, which we also located and geo-located (Appendix A). A total of 99 adult OYA were observed and recorded at a total of 67 locations (Appendix B). Results from riverside observations were consistent with the null hypothesis (Figure 11). Of 29 adults observed along the bottom of the Rio Grande Gorge,

Figure 11. Occurrence of adult OYA along the bottom of the Rio Grande Gorge plotted against distance (m) from the nearest reed patch.

Dispersal of Ochlodes yuma anasazi along bottom of Rio Grande Gorge

25 20 15 10

5 no. of adults no. 0 0 to <1 1 to <3 3 to <6 6 to 10 to 20 to 50 to 100 to >100 <10 <20 <50 <100 <250 distance from common reed (m)

22 (76%) were within 1m of reed, 27 (93%) were within 10m of reed, and no adults were seen more than 80m from common reed. These results suggested a dispersal repertoire more conservative than described by Scott et. al (1977) and similar to that found for Fender's blue (Plebejus icarioides fenderi), a rare Oregon butterfly (Schultz 2008). However, just as the RGG and the Taos Plateau constitute a bi-level landscape, we found a second concentration of OYA adults separate from the larval host stands in the Gorge. BLM's Wild Rivers Recreation Area is situated on the Taos Plateau above the Gorge where access to

16 recreation sites is provided by SR378. Though precipitation had been sparse in 2011 and by late August most of the area remained parched, the right-of-way alongside SR378 offered abundant sources of nectar; poison milkweed (Asclepias subverticillata) and rabbitbrush (Chrysothamnus nauseosus) displayed many blossoms. Walking these roadsides as time allowed during August 26-28, 2011, we searched for adult OYA nectaring at flowers, obtained geographic coordinates for each, and determined the gender of most. Over several hours we recorded 45 adult OYA, including 31 females, 11 males and 3 that eluded gender determination. A 3:1 ratio of females to males is about right for late August. During that point in the flight period most males have flown, mated and expired, while nearly all females are in flight and most have mated. About half of observed females had enlarged abdomens and appeared to be carrying eggs. When all OYA observations made during this three-year study, totaling 99 individual adults, are plotted against distance to the nearest reed patch (Figure 12), several generalizations

Figure 12. Distances (m) of Ochlodes yuma anasazi from reed patches, 2009 - 2011.

Dispersal of Ochlodes yuma anasazi from reed patches, 2009 - 2011

40 unknown 30 males females

20 no. of adults observed of adults no. 10

0-50 100-150200-250300-350400-450500-550600-650700-750800-850900-950 1000-10501100-1150 distance from nearest reed patch

present themselves. First, frequency of OYA adults still decreases rapidly with distance from host reed, but it does not go to zero as rapidly as suggested by data from the Gorge bottom only (Fig. 12). Adults of both genders are willing and able to fly hundreds of meters. These travel distances are considered conservative because (a) each adult may have arrived from a reed patch more distant than the closest one, and (b) adults may have flown farther if they had not stopped to feed. Male and female OYA may have different dispersal capabilities: males were found up to 736m from reed, but females up to 1132m, more than 50 percent farther. This gender difference is consistent with observations of other colonial butterflies (e.g., Kuussaari et al. 1996).

17 Figure 12 also shows that no OYA observations were noted between 100 and 250m from reed patches. This irregularity may reflect the difficulty of searching vertical canyon walls between Gorge bottom and plateau top, or it may reflect some non-linearity in the relationship. For example, in some butterflies dispersal behavior is usually constrained while in close proximity (e.g., 50m) to a patch of host plant, but dispersal efforts increase when individuals find themselves not near a host stand, possibly in an effort to find host (e.g., Schultz 2008). The complicated landscape (Figure 13) within which OYA lives also may help explain why simple mathematical models would not fully describe occurrence of OYA relative to host

Figure 13. Elevation cross-section through the Rio Grande Gorge.

reed. OYA adults exhibited two activity nodes or concentrations. One was near stands of common reed along the Gorge bottom. The second concentration was at nectar, the primary

18 adult food resource which, during August 2011 was several hundred meters or more distant from reed patches. Although terrain directly between Big Arsenic Springs and nectar sources on the Plateau approaches vertical and is not practically searchable except along narrow corridors of established trails, OYA adults frequently made the jump up to the Plateau in search of nectar. Adults seen on the upland exhibited a proximity to major reed concentrations in the Gorge below, as if they emanated from reed patches and flew in all directions. We intercepted some at nectar concentrations, but rarely more than 1km away. Large reed patches like those at Big Arsenic Springs probably generate a considerable output of OYA, while small stands like patch RP-12 along the Red River produce only a few individuals. As we walked along the rim searching, we covered long stretches without seeing any OYA. When we did see an individual it turned out to be a modest distance from a reed patch, and numbers of OYA adults increased as we approached Arsenic Springs (Figure 13). The graph in Figure 12 depicts how far adults might radiate from reed patches in search of nectar or mates and in so doing it suggests the existence of an effective dispersal distance for OYA. Overlaid on the landscape of reed patches, this effective dispersal distance can suggest how frequently OYA from different reed patches might connect with each other. It is notable, and somewhat alarming, to realize that if adults radiate equally in all directions from reed patches, most would travel in directions that would lead them away from, not toward, other reed patches, most of which lie directly up- or downstream. Assuming non-directional diffusion of OYA adults from occupied reed patches to distances up to 1 km from reed beds (from Figure 12), we used an ArcGIS spatial tool to buffer a 1km radius from the centroid of each OYA-occupied reed bed (Figure 14). This permits a preliminary visual evaluation of OYA connectivity within the Gorge, which suggests that OYA adults routinely encounter adults from neighboring reed patches between Big Arsenic Springs and La Junta. The gap south of Chiflo is likely an artifact of our inability to examine reed for OYA there (Figure 9), and will probably close when Felsenmeere Spring reed patches are examined. The gap south of La Junta is real, which makes the southernmost OYA colony at Black Rock Hot Spring a bit of an outlier. Adults may still mix with adults from reed patches to the north, but less frequently. We cannot explain why no OYA evidence was seen north of Chiflo, where there is abundant reed in stands not too widely separated. What becomes of OYA adults that fly up to the higher level of the landscape? First, are they already mated or do they find mates, court or mate while there? Many of the females we observed had enlarged abdomens and appeared to be carrying eggs. Over the course of several hours during excellent mid-day weather conditions near these large nectar patches we observed no courtship or reproductive behaviors among adult OYA. Second, what do OYA adults do when they finish feeding? There are several alternatives, only one of which contributes to dispersal and genetic mixing needed to support the metapopulation. When finished feeding, adult OYA at mesa-top nectar patches might: 1. stay there until they expire; 2. resume flying away from the Gorge and reed beds; 3. return to the Gorge bottom and to the same reed bed where they originated; or 4. return to the Gorge bottom, but not to their reed patch of origin. The first three options do not contribute to OYA dispersal. Option 3 seems unlikely as OYA adults probably lack the required navigational precision. Option 4 would contribute to dispersal, possibly extending an individual's total dispersal range to 2km and contributing to OYA gene flow among reed patches. To answer the question of where adults go after nectaring, future

19 researchers could catch, mark and release OYA at the roadside rabbitbrush, then search in subsequent days for marked individuals flying among reed beds along the river. The proposed dispersal range of 1 to 2km, from reed patch to nectar and back, may represent one day of effort by an OYA adult. An OYA adult that undertook this mission on more than one day could disperse over greater distances.

Figure 14. Hypothetical dispersal ranges from OYA-occupied reed beds.

20 We conclude from these observations that OYA adults are capable of flying somewhat greater distances from reed beds and in greater numbers than has been documented previously for O. yuma elsewhere (i.e., Scott et al. 1977). This willingness to travel modest distances helps explain the presence of OYA immatures at widely scattered reed beds along a 26km reach of the Rio Grande and Red River. The greatest distance between reed beds exhibiting evidence of OYA use was about 9km. Movement of gravid females is demonstrated for distances exceeding 1km and can be reasonably implied for 2km per day. If an adult female were to undertake such activity on two or more separate days, dispersal to 9km or more does not stretch limits of credulity. Then, however, it would be natural to ask why a reed bed only 3km north of Chiflo Spring was not occupied by OYA, but that is the nature of meta-populations. Presence of predatory wasps during field work in July 2011 provided a potential explanation for how OYA immatures could be eliminated from a reed bed, creating a gap in OYA distribution. What is the upper limit of OYA dispersal? There may be no theoretical limit, but there may be a practical maximum. We suggest the 12-mile (19km) distance between reeds near Manby Hot Springs and reeds near Taos Junction Bridge exceeds the practical travel ceiling for OYA adults. If an adult travels 1km per day for its entire adult life of approximately 10 to 14 days, that still would not be far enough to span that distance. Thus reed beds in the Orilla Verde Recreation Area near Pilar may be unreachable by OYA departing from John Dunn Bridge.

Vulnerability Ochlodes yuma anasazi exists as a single metapopulation by capitalizing on discrete host plant stands, or patches, occupying specialized wetland habitats within a 26km reach of the Rio Grande Gorge. Adults of both genders exhibit a dispersal capability that appears sufficient to maintain this metapopulation. This capability clearly is inadequate for OYA to establish reproductive contact with any other known populations of O. yuma, the nearest of which is ca. 250 km distant. This makes OYA potentially vulnerable to deterioration, extirpation or extinction. Adding to its vulnerability is this butterfly's reliance on an obligate wetland/riparian plant in a region where wetlands are as endangered as they are important. "Wetlands and riparian ecosystems comprise less than 1% of New Mexico" (NMDGF 2006), yet "approximately 80% of all sensitive and specially classified vertebrate species in New Mexico depend upon riparian or aquatic habitat at some time during their life cycle" (New Mexico Department of Game and Fish 2000, 2006). New Mexico has lost approximately 90% of its original riparian ecosystems in the past century (NMDGF 2006). "Key areas upon which to focus conservation efforts in New Mexico . . . include riparian and aquatic habitat" because they "contain key habitats, have a high diversity of species of greatest conservation need (SGCN), are subjected to a moderate to high magnitude of multiple habitat altering factors, and lack legal constraints or long-term management plans protecting them from habitat conversion" (NMDGF 2006). "[P]erennial marsh/cienega/spring/seeps and riparian habitats may be at a higher risk of alteration by multiple factors than other habitat types" (NMDGF 2006).

Threats Given the above vulnerabilities, it is important to identify potential threats to persistence of Ochlodes yuma anasazi and to evaluate the seriousness of those threats. Potential threats to this population include direct and indirect threats. Direct threats to the butterfly include:  pesticide spraying for insect control,

21  flooding in the Rio Grande, and  over-collecting for commercial gain. Indirect threats to its habitat or stands of host reed include:  exotic invasive plants  management of invasives  grazing damage to host plant or wetland habitat,  mining impacts on quality of water supporting the host plant, and  desiccation or other hydrologic changes, for example due to climate warming, agricultural water use, or interstate compact obligations.

Insecticide Application Insecticide spraying can be a threat to any insect, including OYA (e.g., http://www.butterfliesandmoths.org/species?l=2111). Fortunately, that portion of the Rio Grande Gorge that hosts OYA currently is managed as a Wild and Scenic River in which spraying of insecticides for insect control is not done. Unless and until that policy changes, OYA colonies are not at risk from this activity.

Rio Grande Flooding Many reed patches occupied by OYA occur on low lands adjacent to the Rio Grande and presumably within the Rio Grande's normal floodplain. These patches and any OYA in immature stages could be inundated during major floods. Fortunately, and perhaps not coincidentally, P. australis and OYA also seem to thrive in seep/spring habitats on valley sides up and away from major watercourses. Even a few feet of vertical separation from the Rio Grande would protect such stands from floods and many reed patches fit that description. Thus OYA does not depend on streamside reed patches for survival. Riverside reed patches may facilitate OYA dispersal between more permanent seep/spring colonies, even if those riverside colonies prove to be temporary.

Over-utilization for Commercial, Recreation, Science, or Education Over-collecting is a concern for some insects, particularly butterflies, which may be highly sought after for their beauty, especially if rare (USFWS 2004). Federal listing could increase the publicity and interest in a species’ rarity, and thus may directly increase the value and demand for specimens (Ehrlich 1989). OYA is not particularly conspicuous or beautiful. Nevertheless, upon formal description of OYA (Cary and Stanford 1995), at least one collector visited the site and took home a large number (~50) of pupae. Fortunately, sites occupied by OYA pose access challenges varying from mild to severe. Some reed beds are reasonably accessible by hiking down into the Gorge on decent trails, but many have no trail access and, without trails, overland approaches are extremely challenging due to large, steep rockslides and extensive fields of large boulders. Some sites occupied by Yuma are easily reached by floating/paddling down the Rio Grande, but other sites occur along reaches that are difficult to safely navigate in that manner due to intense rapids and whitewater. In this sense, use by OYA of a large number of dispersed reed beds would offer better protection against excessive collecting. Presently, some local reed beds are vulnerable to over-collecting, while others are hard to reach without investing considerable time and effort. OYA probably is not threatened by over-collecting at this time, but land managers may want to monitor collecting

22 interest and activities. If the number of occupied reed beds decreases in the future, then this population could become increasingly vulnerable to over-collecting.

Exotic Invasive Plants Phragmites australis occupies an ecological niche that is vulnerable to invasion by non- native plants, as "(M)any of New Mexico’s riparian communities have been altered by invasive species" (NMDGF 2006). Nonnative plants that have invaded riparian zones in the region include tamarisk, Russian olive, Siberian elm, perennial pepperweed, Canada thistle, teasel and Russian knapweed (USDI-BLM 2010). Herbaceous wetland invasives such as purple loosestrife are reported from the region, though not yet from the Rio Grande Gorge. Any future infestations could prompt management actions and any such actions could pose potential threats to other wetland plants, such as P. australis. Elsewhere in New Mexico, exotic woody plants that are prolifically invasive and damaging to riparian and aquatic habitats include salt cedar (Tamarix spp.), Russian olive (Eleagnus angustifolia) and Siberian elm (Ulmus pumila). Where these plants gain a foothold, they can out-compete native plants and form thickets that alter first the structure and then the species composition of local ecosystems. Common reed does not tolerate shade, and if these exotic trees/shrubs proliferate they could shade out reed beds and reduce habitat for OYA. These three exotic plants are present in the study area, though currently in low numbers. Land managers in the Gorge should monitor salt cedar, Russian olive and Siberian elm and be prepared to act as necessary to protect native reed beds.

Management of Invasive Species Common reed occurs in several known forms that are visually and ecologically similar, but genetically separable. An Old World form introduced to North America relatively recently is aggressively invading aquatic and estuarine habitats in the eastern US to the extent that it is considered an invasive exotic plant that requires management in order to protect native aquatic ecosystems (Saltonstall 2002). This ironic situation raises several questions relevant to a threat analysis for OYA. Which form of reed lives in the Rio Grande Gorge? This question can be answered only with appropriate genetic analysis of samples from the Gorge, which is beyond the scope of this study. Common reed has been present in North America for millennia (Kiviat and Hamilton 2001). While evidence for this antiquity is scarce in eastern North America, it is abundant in the American Southwest (e.g., Adams 1990). Genetic analyses reported to date suggest that indigenous genotypes still prevail in western North America (Blossey et al. 2002). The Rio Grande Gorge has not been heavily affected by other exotic invasive riparian/aquatic plants, so perhaps reeds in the Gorge are of an indigenous type. Will OYA larvae eat the non-native strain of reed? This question has been raised in other western locations. If they do with no loss of vigor, then invasion of non-native reed may not pose a direct threat to OYA. Early indications (e.g., Pyle 2002) suggested that O. yuma would not use the non-native reed, in which case invasion of native reed patches by the exotic strain might pose a threat to OYA. Since then, California subspecies O. y. sacramentorum was found to use the exotic form (www.xerces.org/wp-content/uploads/2008/09/ochlodes_yuma1.pdf). In Nevada, invasion of aquatic habitats by the new reed genotype generated large reed beds and expanded local populations of O. yuma (Nelson 2009). No evidence is yet available for OYA one way or the other. If OYA will not eat the non-native strain, then invasion of the non-native reed

23 could be adverse to survival of OYA. If the butterfly proves to do equally well on native and non-native reed strains, then the exotic strain would pose no threat to the butterfly. If any form of the common reed becomes invasive in the Gorge, begins to dominate and de-stabilize local riparian/aquatic ecosystems, and yet proves to be a viable food resource for OYA larvae, then management efforts to control exotic reed populations could pose a threat to the butterfly. Already the spread of common reed elsewhere in New Mexico has raised management concerns (e.g., Lang 2005). Elsewhere in the US, responses to invasion of common reed have included massive herbicide application campaigns (e.g., Chambers et al. 1999). Destruction of OYA's sole larval host plant, whether a native or non-native genotype, would pose a real problem for the butterfly. Resource managers should carefully evaluate control of invasive species in areas occupied by OYA.

Livestock Grazing There is no livestock grazing within the riparian areas of the Rio Grande Gorge as per the direction of the Rio Grande Corridor Plan (USDI-BLM 2000). This policy would continue as proposed in the Draft Taos Resource Management Plan and Environmental Impact Statement (USDI-BLM 2010). Livestock grazing is not a significant threat to OYA.

Water Pollution About 10 miles east of the Gorge is the Molycorp molybdenum mine - an open pit mine with many acres of waste piles and tailing ponds that are the subject of a federal Superfund cleanup action (http://www.epa.gov/region6/6sf/pdffiles/0600806.pdf). Tailings spills into the Red River plagued the facility for many years. Waste piles east of Questa are open to atmospheric precipitation, which leaches contaminants into local groundwater. Tailing ponds west of Questa are not lined with impermeable material and constantly leak high salinity water into the local aquifer (www.amigosbravos.org/docs/molycorp/epa_report.pdf). Environmental impacts of this operation were the subject of a 2009 clean-up plan (www.epa.gov/region6/6sf/newmexico/molycorp/nm_molycorp_proposed_cleanup_plan.pdf). The U.S. Environmental Protection agency signed the Record of Decision for the cleanup in December 2010 (http://www.epa.gov/region6/6sf/pdffiles/0600806.pdf). So far the principal impact of molybdenum mining on local water quality seems to be on salinity. If such salinity impacts were to reach Gorge springs, how would reed patches respond? On one hand, common reed is known to tolerate alkaline or saline water at other sites (e.g., Scott et al. 1977). Habitat disruptions such as altered water chemistry have been noted to stimulate spread of Phragmites in some cases (e.g., Marks et al., 1994). This invasion is often effected by the non-native genotype of Phragmites, which seems to be more salt-tolerant than native genotypes (Vasquez et al. 2005). Such a response might be anticipated in the study area as well. Then the issue could come down to whether land managers would see a need to manage Phragmites, and how to do it. Lambert and Dudley (2008) described the issues that arise in this scenario. The future trajectory of water quality in Gorge springs may influence the future success of the non-native reed genotype and of OYA. Presence of this large water contamination source up-gradient from the OYA population in the Gorge is a potential cause for concern. In the 1980s, Molycorp proposed to move the source closer to the Rio Grande by creating a new tailing disposal area in the saddle of the Guadalupe Mountains, only two miles from the junction of the Red River and Rio Grande. Such an action would substantially increase the risk of water quality impacts to Gorge seeps and

24 springs, and so to plants and animals depending on those habitats. Molycorp has had a long and important economic presence in Taos County. As one of few operational molybdenum mines in the US, it is likely to be around for decades to come. At the same time, increased recreational infrastructure and uses in the BLM Wild and Scenic Rivers Recreation Area may offer something of a counter-balance to future increases of mining impacts in the study area.

Climate Warming This is an ongoing process that is projected to make New Mexico warmer and drier (NMED 2005). Anticipated changes related to water resources include: greater evaporative loss from lakes and reservoirs; greater evapotranspiration from soils and plants; less runoff and more soil drought for a given amount of precipitation; smaller mountain snowpacks; snow melting earlier in the year; and reduced groundwater recharge. For the study area, these changes would likely translate into reduced snowpack in the Sangre de Cristo Mountains, reduced snowmelt runoff, reduced recharge to local aquifers, and reduced flow of seeps and springs in the Gorge. Reduction of seep/spring discharge could result in loss of some seeps/springs and reducing the size of other springs. This could reduce suitable habitat for common reed, which might be expected to occur in fewer, smaller patches within the Gorge. Reduction in host plant populations would likely reduce the extent, connectivity and viability of the OYA metapopulation in the Gorge.

Table 1. Threat Assessment for OYA.

Potential threat Near-term risk Long-term risk Insecticide application Low Low Over-collecting Low Low Flooding Low Low Livestock grazing Low Low Drying of spring habitats Low High Mining pollutes water Moderate Moderate Invasive exotic species Low Moderate Management of invasive plants Low Moderate Climate warming Low High

Overall, OYA would seem to have a high probability of ecological and habitat stability for the next several years. Its habitat and home range are designated and managed as a federal Wild and Scenic River. The current land manager, the US Bureau of Land Management (BLM) is managing the Gorge and its resources in a way that is not likely to interfere with continued persistence of OYA, at least for the immediate future. The most serious potential threats, such as invasive species, climate warming or water pollution, would come from outside the Gorge itself and would take longer (several to many years) to materialize and longer to have an adverse impact. It is conceivable that two or more threats could act synergistically or cumulatively to adversely affect the future of this species. For example, climate warming could reduce spring discharge, increase salinity of spring waters, and encourage more invasive species.

Future Work Common Reed. Long term understanding of OYA in the Gorge depends on understanding and monitoring changes in reed populations. If OYA becomes the subject of future studies geared toward its conservation, it will be important to:  establish a detailed and complete map of reed patches in the Gorge;  quantify each patch in terms of area, stem density, stem height; and  monitor those patches periodically into the future to detect changes in their number, size, location or health. Step one in such an effort is to fully document the current reed population in terms of location, size and health of all reed beds. Certain areas of the Gorge could not be completely surveyed during this study due to time, access challenges, and the difficulty in obtaining clear views of the entire Gorge. Paddling the river from top to bottom in June or July, excluding Class V reaches, would allow access to all riverside reed patches. Reed beds that are away from the channel are best viewed from above and will be hardest to locate. Perhaps a low elevation, low-speed, high resolution, GIS-synchronized aerial photography run, would be the most efficient way to do the job. It may also be important to quantify each patch in terms of area, stem density, and stem height. These factors may help understand the value or utility of each patch to OYA. Ochlodes yuma anasazi. There is a need to examine more reed patches south of Taos Jct. Bridge for evidence of OYA. There are more than 20 patches and some are rather large, but all are on the west side of the Rio Grande and thus difficult to access. We examined two prominent patches for evidence and found none, but that is hardly conclusive. A float from the Bridge through part of the Racecourse section of the Rio Grande, with some occasional uphill hiking, would provide relatively easy access to most of the unexamined reed patches. Research is recommended to flesh out details of the population structure of OYA. The primary role of Big Arsenic Springs in the source-sink metapopulation is understood, but additional field work is needed to confirm the presence or absence of other potential major population centers, for example at Manby Hot Springs, Felsenmeere Springs and Chiflo Springs. Mark-release-recapture (MRR) studies could improve knowledge of OYA population size and help to understand dispersal of OYA between main population nodes in the Gorge. OYA concentrations at easy-to-reach nectar along SR 378 invite further MRR studies to better understand the role of nectar sources on the Taos Plateau and OYA travel between plateau-based nectar sources and Gorge-based reed beds. We found considerable variation within and between reed patches in terms of stem height and density, but did not systematically quantify these variables for each patch. These characters may influence predation and parasitism of OYA immatures. Some unoccupied reed patches (e.g., at Lone Tree Spring) were heavily invaded by coyote willow, causing elevated stem densities of willow plus reed that may interfere with normal OYA patrolling, courting and oviposition behaviors. Future investigations might evaluate patch characteristics with respect to behavioral, survival and reproductive requirements of OYA. Threats. Work is needed to more fully characterize the nature and severity of some threats to OYA. Once characterized, regular and long-term monitoring of water quality at springs and seeps, spring discharge, invasive plants (especially U. pumila, Tamarix sp., and E. angustifolia), reed populations and OYA populations is recommended. Studies are needed to determine the genotype of reeds in the Gorge and the region. If non-native genotypes are found, laboratory feeding experiments could compare larval survival on native and non-native reeds.

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Figure 15. The rafting expedition prior to departure, July 22, 2011, photo by W. Blackstock.

30 APPENDIX A

One hundred twenty eight patches of common reed (Phragmites australis) were identified during this study and characterized in terms of location of patch centroid and estimated patch size (m2). We found considerable variation among patches in terms of the stem height and density, but did not systematically quantify these variables for each patch.

Table omitted in order to protect locations. Full report is available from the New Mexico Game and Fish Department: Chuck Hayes Share with Wildlife Coordinator New Mexico Department of Game and Fish One Wildlife Way Santa Fe, NM 87507 APPENDIX B Data table for adult Ochlodes yuma anasazi observations.

32 APPENDIX C Detailed Reed Patch Maps

Maps omitted in order to protect locations. Full report is available from the New Mexico Game and Fish Department: Chuck Hayes Share with Wildlife Coordinator New Mexico Department of Game and Fish One Wildlife Way Santa Fe, NM 87507