GOLDEN EAGLES (Aquila Chrysaetos) NESTING IN OREGON, 2011–2018

Annual Report

Frank B. Isaacs

Oregon Eagle Foundation, Inc. 24178 Cardwell Hill Drive Philomath, OR 97370, USA 541-231-1674, [email protected]

20 February 2019

1 GOLDEN EAGLES (Aquila chrysaetos) NESTING IN OREGON, 2011– 2018: Annual Report

Suggested Citation: Isaacs, F. B. 2019. Golden eagles (Aquila chrysaetos) nesting in Oregon, 2011–2018: Annual Report, 20 February 2019. Oregon Eagle Foundation, Inc., Klamath Falls, Oregon, USA.

POPULARIZED INTRODUCTION & SUMMARY The golden eagle (Aquila chrysaetos) is found throughout the Northern Hemisphere. In North America, it occurs from the arctic to central Mexico and is one of the largest North American raptors. In Oregon, golden eagles occur statewide and are most common in the eastern half of the state. Migrant golden eagles from other areas visit the state in the winter, while nesting pairs mostly appear to be year-round residents. Golden eagles take five years to attain full-adult plumage and can breed prior to that. Subadult golden eagles can stay close to their natal areas as they mature or may travel great distances from where they were hatched, or both. Non-breeding golden eagles from Oregon may visit surrounding states, and those from surrounding states may spend time in Oregon. There were no statewide research projects on golden eagles nesting in Oregon until this study. The project was initiated in 2011 because of concerns about the effects of energy development on the species. The goal of this work is to find as many golden eagle nests in the state as possible each nesting season (February through July) to document nest use and determine how many eaglets are raised each year. Over 60 organizations and 700 individuals, including citizen science volunteers have contributed to the project. Through 2018, 1,018 golden eagle nesting areas have been identified, 577 were reported before 2011, and 441 have been added since. Each year ~77% of nesting areas were observed; ~58% of the observed nesting areas were occupied; nesting outcome was determined at ~87% of occupied nesting areas; and ~59% of those with known outcome were successful. As a result of that effort, a total of 2,246 golden eaglets were counted from 2011–2018 in Oregon. The minimum golden eagle nesting population for Oregon was estimated at ~589 nesting pairs; and the minimum number of eaglets produced each year was estimated at ~486. 2019 will be the ninth consecutive year of what we hope will be a ten-year project that will end after the 2020 nesting season and provide a valuable description of the status of nesting golden eagles in Oregon at the beginning of the 21st century.

2 ABSTRACT The current list of 1,193 golden eagle nesting areas (NA) in Oregon consists of 577 reported before 2011 and confirmed during this study (48%), 441 first reported during 2011–2017 (37%), 124 reported prior to 2011 and searched but not confirmed (10%), and 51 reported before 2011 that have not been visited (4%). Additional undiscovered NAs likely exist in un-searched habitat throughout the state. Mean annual nesting results were 58% occupied (range 52%–62%), 59% successful (range 45%–71%), 0.81 young per occupied nesting area with known outcome (range 0.63–1.04), and 1.38 young per successful nesting attempt (range 1.28–1.46). Mean estimated minimum statewide nesting population was 589 nesting pairs (range 533–632), and mean estimated minimum production was 486 eaglets per year (range 346–619). NA occupation increased from 46% when observed one year (n = 78) to 94% when surveyed eight years (n = 240). Successful nesting at least once increased from 58% for NAs with one year of known outcome (n = 144) to 97% for NAs with eight years of known outcome (n = 36). Those data on occupation and nesting success show the value of multiple years of monitoring. Fifty-two percent of nests (n = 2,677) were on land managed by Bureau of Land Management, 30% were on private land, 10% were on U.S. Department of Agriculture land, 3% were on land managed by U.S. Fish and Wildlife Service, and 5% were divided among five other entities. Nests were built on cliffs (76%), in trees (22%), and on electricity pylons (2%, n = 995). Egg-laying and initiation of incubation began during the week of 29 January–4 February, peaked during 26 February–3 March and ended the week of 1–7 April (n = 478 estimated nesting chronologies). Egg-laying dates determined subsequent timing of incubation, hatching, and eaglet development, with the peak abundance of 8–10 week old eaglets occurring in mid-June. One-hundred-two eaglets were banded at 68 nesting areas and 10 were equipped with satellite transmitters during 2012–2014. One banded juvenile was captured near Prescott, Arizona and released unharmed, and one was electrocuted near its natal nest near Crane, Oregon. As of 25 February 2018, all ten radioed nestlings either died or had shed their transmitters after fledging. Continued inventory of listed NAs, additional searches of likely habitat, and continued monitoring of occupied NAs are recommended.

3 INTRODUCTION

The golden eagle (Aquila chrysaetos) is distributed throughout the Northern

Hemisphere, primarily between 20° and 70° N latitudes (Watson 1997:22). In North

America, the species is most abundant west of 100° W longitude from the arctic slope to central Mexico (Kochert et al. 2002:3) and nesting occurs over a wide range of elevations in open and semi-open habitats (Kochert et al. 2002:7). Golden eagles have been observed throughout Oregon and nesting has been documented in all counties east of the Cascades and in 9 of 18 counties west of the Cascades (Carey 2003:161,

Isaacs & Opp 1991, this study).

Golden eagles are protected by the Migratory Bird Treaty Act in Canada, the U.S. and Mexico, and the Bald and Golden Eagle Protection Act in the U.S. (U.S. Fish and

Wildlife Service 2009). In Oregon, golden eagles are designated as protected non-game wildlife by Oregon Department of Fish and Wildlife (2010). Suspected long-term population decline (Kochert et al. 2002:26) and recent resource development and related eagle mortalities resulted in concerns about the status and future of the species in the western U.S. (U.S. Fish and Wildlife Service 2010, Pagel et al. 2013). However, subsequent trend analysis indicated that golden eagles were not declining widely in that area (Millsap et al. 2013).

The population of nesting golden eagles in Oregon was estimated at a minimum of

500 nesting pairs in the mid-1980s, however that estimate was based on limited and inconsistent monitoring and rough estimates of survey coverage (Isaacs & Opp 1991).

In addition, statewide population trends could not be determined from those data because of inadequate monitoring (Isaacs & Opp 1991). Local studies within Oregon

4 correlated golden eagle nesting success with black-tailed jackrabbit (Lepus californicus) abundance during 1966–1980 in southeastern Oregon (Thompson et al. 1982), suggested population increase from 1972–1989 in Baker County, northeast Oregon

(Larry Roumpf, Baker City, OR, personal communication), and suggested population decline in central Oregon from 1966–1984 (Anderson 1985). Despite those efforts, the size, distribution and productivity of the population of golden eagles nesting in Oregon had not been determined and statewide trends in those parameters were unknown.

Current efforts by U.S. Fish and Wildlife Service (USFWS) to protect golden eagles and ensure no declines in breeding populations (Pagel et al. 2010:2) require baseline and trend information on size, distribution, and productivity. The objectives of this project are to determine those parameters for nesting golden eagles in Oregon. The goal is to provide baseline information required to determine long-term trends in the status of the golden eagle breeding population as was accomplished for peregrine falcons (Henny & Pagel 2003, Isaacs 2008) and bald eagles (Isaacs & Anthony 2011).

This report contains results of golden eagle nest survey, inventory, and monitoring in

Oregon through 2018.

5 ACKNOWLEDGEMENTS

Without grants and cash contributions this project could not have been done. That funding, in descending order by amount contributed, has been provided by:

U.S. Bureau of Land Management (BLM) Bonneville Power Administration (BPA) U.S. Fish and Wildlife Service (USFWS, Western Golden Eagle Team (WGET) Avangrid - Iberdrola Renewables USFWS - Region 1 - Oregon Fish and Wildlife Office Gary Landers EDPR North America Portland General Electric (PGE) Oregon Eagle Foundation, Inc. (OEF) American Wind Wildlife Institute (AWWI) American Wind Energy Association (AWEA) The Estate of Daniel Joseph Wadosky Orion Renewables RES America Developments, Inc. E.ON Climate & Renewables North America, Inc. Oregon Department of Fish and Wildlife Eurus Combine Hills II Invenergy U.S. Forest Service (USFS) Eurus Combine Hills I USFWS - Region 1 - Migratory Birds BP Wind Energy enXco Gray Family Foundation Anonymous Private Individual Bill Price Memorial Fund Ray Temple & Stephanie Hazen Hoffmann Family Fund Richard Hoyer Firstwind East Cascades Audubon Society (ECAS) Marilynne Keyser Oregon Parks and Recreation Department (Eagle Watch Sales) Gregory Stempien Lynn Sharp William Pearcy J.M. and L.E. Bousquet, Jr. Connie & Joseph Jones George Boehlert

6 Paul Miller & Kathy Cushman Friends of the Sisters Library (FOSL) David Anderson of Boise Idaho David Vick Camp Sherman Waste Transfer and Recycling Site Friends and Neighbors of the Deschutes Canyon Area (FANS) Rogue Valley Audubon Society Kevin Smith Salem Audubon Society (SAS) Grainger Hunt Lawrence Pearcy Kathryn Duman Ralph & Charlotte Opp, and Andrew & Katherine Passarelli.

Special thanks to every cash contributor!

Nest entry for banding, telemetry and contaminant research during 2012–2014 was funded by USFWS (Oregon Fish and Wildlife Office and Western Golden Eagle

Team). Special thanks to the late Bill Price for managing OEF’s nest entries and to

Carole Hallett, Eric Forsman, Jeremy Buck and David Leal (USFWS), David Anderson

(The Peregrine Fund), Dan Varland (Coastal Raptors), Collin Eagles-Smith and Garth

Herring (U.S. Geological Survey), Simon Wray (Oregon Department of Fish And

Wildlife), Andrew Shields (Roaring Springs Ranch), Thad FitzHenry and Greg

Concannon (PGE), Jim and Sue Anderson (Natural Selection), Gary Landers, R.

Ahrens, Jerry Broadus, Chris Carey, Rita Claremont, Katy Duffy, Gabe Dunham, Nathan

Gerhardt and Rick Gerhardt (Sage Science, Inc.), Miranda Kreb, Kristi Lahusen,

Candace Larson, Rebecca Migala, Sarah Norton, Andrew Rosenberg, Julie Schneider,

Matt Stuber, Fiona Toland, Bridget Tuerler, John Waller and Eric Williamson for their contributions. Additional technical assistance for nest entries was provided by Peter

Bloom (Bloom Biological), Michael Kochert (U.S. Geological Survey), Rob Domenech

7 (RaptorView), and Kevin Maurice (USFWS). Technical assistance with equipment was provided by Ryan Bonner (Alcoa Fastening Systems) and Sterling Rope. Thanks to

Malheur National Wildlife Refuge (MNWR) and Burns BLM for providing housing for the banding team, and to MNWR refuge staff, Jim Dastyck, Tim Bodeen, Chad Kargas,

Carey Goss and Jess Wenick for additional logistical support. Candace Larson, intern at

MNWR sponsored by Audubon Society of Portland, provided valuable assistance to nest monitoring and banding efforts. Banding eaglets in nests on private property would not have been possible without the cooperation and assistance of ranchers David and

Janna Mims, Harvey and Patsy Cronin, Toby Cronin, Don Dryer, Ross and Angie

Ketscher, Gary and Georgia Marshall, Shirley Thompson and her son, David Thompson, and other cooperating Harney and Malheur County ranchers.

Jim and Sue Anderson, Natural Selection, Sisters, OR; Charlie Bruce, ODFW retired, Corvallis, OR; Chris Carey, ODFW retired, Bend, OR; Gary Clowers, Raven

Research West, Madras, OR; Rick Gerhardt, Sage Science Inc., Madras, OR; Jim

Harper, BLM retired, Medford, OR; George Keister, ODFW retired, Baker City, OR;

Charlie Thomas, BLM retired, Eugene, OR; Rick Vetter, USFS retired, Burns, OR; and

Walt Wolfe, Science Teacher retired, Madras, OR deserve special mention for their outstanding contributions. Their knowledge of golden eagles in general, and regional nest locations and histories in particular were invaluable. In addition, their long-term perspectives on golden eagle population and habitat changes, and the impacts of increasing human population on the species were enlightening.

Additional, in-kind assistance came from Renewables Northwest Project, especially Pam Mahon, Megan Decker and John Audley; wind industry cooperators;

8 wildlife consultants, especially Karen Kronner, Bob Gritski and Rick Gerhardt of

Northwest Wildlife Consultants, Inc.; agency cooperators; golden eagle experts; and volunteers. Rob Spaul, Boise State University, Boise, ID; Portland General Electric

(PGE); Northwest Wildlife Consultants, Inc., 2Morrow Energy, WEST Inc., Wheatridge

Wind Energy LLC, NextEra Energy, Oregon Wind Farms and ABR Inc. generously contributed results of their golden eagle nest surveys. Thanks to Bend Park &

Recreation District, USFS, BLM and Oregon Department of Fish and Wildlife (ODFW) for providing meeting rooms free of charge.

Many people (at least 707) and organizations (at least 55) contributed to the project and are recognized in Appendix 1. Volunteers deserving special mention were

Charlie Bruce, Corvallis, OR; Jim Harper, Medford, OR; George Keister, Baker City, OR;

Gary Landers, Sisters, OR; Steve Lay, Terrebonne, OR; Miriam Lipsitz, Bend, OR; Dick

Musser, Vale, OR; Bill Price, Hillsboro, OR; Dede Steele, Post, OR; Charlie Thomas,

Eugene, OR; Rick Vetter, Burns, OR; David Vick, Terrebonne, OR; and Walt Wolfe,

Madras, OR.

I am grateful to all who contribute to this project; it could be done without their continued participation and support. My apologies to those I failed to recognize. I alone am responsible for the accuracy of data summaries and conclusions, and am accountable for any errors herein. Bob Anderson, Charlie Bruce, Rick Gerhardt, Michael

Green, Jim Harper, Richard Hoyer, George Keister, Gary Landers, David Leal, Jane

Olson, Bill Price and Larry Reigel provided valuable review comments.

Finally, I’m especially grateful to Jane Olson for keeping our household running smoothly through 26 eagle nesting seasons. Her bountiful gardens and our wonderful

9 children were always a pleasure to return home to after a week in the field. Jane’s support has been a significant contribution to all aspects of research on eagles in

Oregon.

SPECIAL DEDICATIONS

This report is dedicated to Bob Anthony (1944–2013), Bill Price (1943–2014), Dan

Wadosky (1951–2015), and Sergej Postupalsky (1934–2016):

Bob was an outstanding wildlife biologist, researcher and teacher. His dedication to the wildlife profession and strong advocacy for research-based wildlife management was an inspiration to his students and colleagues.

Bill was involved in all kinds of outdoor activities and especially loved sharing his outdoor skills with children. He made outstanding contributions to natural history research and education in Oregon and nationally.

Dan loved the wild and was a champion of conservation in Oregon. He was passionate about rivers and fishing, and supported the Oregon Rivers Initiative and Oregon Natural Desert Association. Oregon Eagle Foundation is grateful for the generous contribution from Dan’s estate that was used for research on golden eagles in Oregon.

Sergej was a pioneering raptor researcher who developed nest monitoring techniques and terminology, and made outstanding contributions to the recovery of bald eagles and osprey in North America. His advice that, “even the worst field notes are better than the best memory” has guided my record keeping through the years.

Thanks to Bob, Bill, Dan, and Sergej for their contributions and inspiration!

10 VALUE OF CONTRIBUTIONS

Seven-hundred-nineteen people and organizations have contributed to the project, including at least 396 volunteers, and 323 people from 55 different organizations

(Appendix 1). Unreimbursed time and travel amounts were solicited from volunteers doing field work to estimate the value of those contributions. Total estimated value of unreimbursed time, travel and other contributions by volunteers for survey and nest entry during 2011–2018 was $513,147 (Table 1). This estimate was conservative

because volunteers did not claim all of their time or travel and hourly rates were lower than real costs for professional contributions. Volunteer contributions worth at least

$513,147 comprised 31% of $1,665,575 accounted project value (Figure 1). Additional, unaccounted in-kind services were provided by government and private cooperators.

11 STUDY AREA

The study area is the U.S. state of Oregon which is located halfway between the equator and north pole on the west coast of North America. The state is roughly rectangular in shape, with the widest points being ~620 km (385 mi) east to west and

~476 km (296 mi) north to south covering 251,419 square kilometers (97,073 square miles) of land and water. Oregon is divided into distinctly different east and west regions by the Cascade Mountains. Roughly 1/3 of the state is west of the crest of the

Cascades and 2/3s is east of the mountains. Western Oregon is mostly forested, below

12 914 m (3000 ft) elevation, and has a maritime climate. Eastern Oregon is mostly higher than 914 m elevation, has more open grassland and shrub-steppe than forest, and has a continental climate that is drier and has greater temperature extremes than west of the Cascades (Marshall et al. 2003:4–21). In general, most of eastern Oregon, the

Willamette Valley of northwestern Oregon, and portions of southwestern Oregon are typical golden eagle habitat with open and semi-open areas for hunting and abundant cliffs, rock outcrops and/or trees for nesting.

METHODS

Historical (pre 2011) records of golden eagle nest locations and nest use were solicited from state and federal government agencies, conservation organizations, private companies, and private individuals in 2010. Records were compared to previously reported statewide lists (Hickman 1968, Isaacs and Opp 1991, Isaacs and Popp 1994) and compiled into a golden eagle nest location inventory for the state. Precision of historical locations varied from general legal locations (Township, Range, Section) to relatively precise Geographical Positioning Systems (GPS) point locations. The year that a nest location first appeared in historical records or the year of discovery during this project, was assigned as the first year reported for the corresponding nesting area.

History of nest use was recorded by year and location starting with the first year reported. Nesting histories ranged from nothing reported to reports with annual nesting outcomes reported for multiple years.

Golden eagle nests occurred singly or in clusters on the landscape and were cataloged as nest locations. Each nest location represented one or more nests

13 depending on distance between nests. In general, multiple nests that were too close together to map individually on 7.5’ USGS topographic maps were recorded as a single nest location. Nest locations were grouped into suspected nesting areas (NAs) based on proximity and nesting history, and assuming the potential for one nesting pair per nesting area. NAs included locations of known (with history of occupation) and suspected (without history of occupation) golden eagle nests. In general, nest locations that were <3.2 km (2 mi) apart were grouped into a single NA, and locations >3.2 km apart were considered to be different NAs. However, historical locations <3.2 km apart were designated as different NAs if each had evidence of historical occupation by different nesting pairs during the same year. Historical nest locations (pre 2011, n =

1,520) provided the baseline of nest locations for 2011 field work. Historical plus previously undocumented nest locations added each year provided baseline locations for the following years.

Field work consisted of inventory of historical and recently confirmed nest locations, searches of likely habitat for previously unreported nests, and monitoring of occupied breeding areas to determine nesting outcomes. Project personnel, some agency cooperators, and most volunteers conducted field work on the ground. Most results reported by industry consultants and some by agency cooperators and volunteers were from aerial surveys, and most monitoring in Sherman, Gilliam and

Morrow counties was by air survey by helicopter. Most field work was conducted during

March–July, with additional observations in February, August and September, and was targeted rather than distributed evenly over the study area. Inventory and survey locations were targeted for several reasons, including focus on energy-related project

14 areas, re-survey of areas with monitoring history, proximity to historical nest locations, seasonal accessibility, and local interest. Field work consisted of visiting historical nest locations and adjacent potential nesting habitat, searching for nests and golden eagles, and recording observations on data sheets or in field notes. Primary results of inventories and searches were GPS coordinates of nests determined as precisely as possible. Results of monitoring were descriptions of nest locations, golden eagle behavior, and nesting status observed within NAs.

Nest locations referred to one or more nest structures and were designated by seven-place, alpha-numeric location codes, e.g. H0001AC or C0001AC. Location codes consisted of an era prefix (“H” = historical location reported prior to 2011, or “C” = current nest location reported during 2011–2018), a four-digit nesting area number starting with “0001” that was assigned sequentially as historical nesting areas were added to the inventory list (0001–0999 used for historical NAs, and 1000+ used for previously unreported NAs), a letter for the sequence in which the location was added within a NA ( “A” = first location, “B” = second location, etc.), and a letter designating the nest substrate (“C” = cliff, “T” = tree, and “P” = electricity pylon or other artificial structure). Thus, H0001AC described the first nest location (A) for NA 0001 that was reported prior to 2011 (H) and was on a cliff (C). In addition, starting in 2017, a suffix

( _x) was added to current location codes (prefix C) to designate the number of nests reported for the location (e.g. _1, _2, _3, etc). An example of a current location with four cliff nests would be C1439AC_4. Each NA also was given a unique name, usually based on local geographical features. NAs could have both “H” (historical) and

“C” (current) locations that may or may not have referred to the same actual nest(s). “H”

15 locations were removed from the inventory list when they were replaced by corresponding “C” locations or determined to be erroneous.

Landowner for each nest location listed through 2018 was derived using GIS by

USFWS (Larry Reigel, USFWS, Portland, OR, personal communication). Ownership categories were: Bureau of Indian Affairs, Bureau of Land Management, Bureau of

Reclamation, National Park Service, Private, State of Oregon, U.S. Army Corps of

Engineers, U.S. Department of Agriculture, and U.S. Fish and Wildlife Service.

Monitoring terminology, protocol, and data summary were based on Postupalsky

(1974, 1983), Steenhof (1987) and Steenhof and Newton (2007) with modifications described in Isaacs and Anthony (2011:20), and the addition of codes “OCUX” and

“UNXX” created for this project (Appendix 2). An annual outcome code was assigned to each NA based on the extent of monitoring and observations of nest status or eagle behavior (Appendix 2). Terminology differed from what has been used in previous raptor literature. Historical terms that often were vague, undefined or used improperly were replaced with more descriptive categories (Appendix 3). Outcomes were tabulated and summarized to produce annual data on occupation, nesting success, productivity, and brood size.

Minimum statewide nesting population and productivity were estimated annually based on the most recent number of confirmed nesting areas. Estimates were calculated using the following formulas:

1 - Minimum Nesting Population = Number of NAs Listed X Annual Percent Occupied;

2 - Minimum Production = Minimum Nesting Population (result of formula 1) X Annual Number of Young Per Occupied NA With Known Outcome.

16 Nesting areas were categorized as occupied if a nest and at least 1 breeding age golden eagle were observed at the site during the nesting season, and successful if at least one eaglet was observed and assumed to have survived to fledging. The effect of the number of years observed on occupation and success were investigated by comparing the proportion of nesting areas occupied or successful at least one year between groups of nesting areas with known outcome that were observed 1–8 years.

Nesting areas were grouped by the number of years observed (1–8) and categorized by number of years occupied or successful (0–8) at least once. Percent occupied and percent successful (based on occupation or success at least one year) were calculated for each category.

Age of eaglets was estimated to week (wk) based on illustrations in Hoechlin

(1976), Driscoll (2010) and the following written guide:

0–1 wk - Short grayish-white down. 1–2 wk - Long wooly white down developing. 2–3 wk - Long wooly white down nearly complete. 3–4 wk - Pin feathers begin to show as dark spots on edges of wings and tail. 4–5 wk - Body evenly mottled dark and white; head and neck white. 5–6 wk - Body nearly feathered (dark) except for head and legs. 6–7 wk - Body nearly feathered and head partly feathered. 7–8 wk - Feathers nearly complete; tufts of down on head. 8–9 wk - Feathers complete; "golden" hackles and white at base of tail visible. 9+ wk - Feathered and ready to fledge.

Date and eaglet age were matched with a standard nesting chronology based on

6 weeks of incubation, 1 hatching week, and 10 weeks after hatching. One nesting chronology per breeding area with known age eaglets per year was used in the analysis. When a nest contained >1 eaglet and there was >1 week difference in plumage development between siblings, the estimated age of the most developed eaglet was used in the nesting chronology summary. Chronologies were summarized by

17 seven-day period, corresponding eaglet age, and nesting stage (egg-laying, incubation, hatching, 1–3-week-old eaglets, 4–7-week-old eaglets, and 8–10-week-old eaglets) to create a nesting phenology for the population.

Nesting success by years and regions were calculated for basic data summaries.

Regions were based the following individual or groups of counties: Western (WEOR) =

Clackamas, Coos, Curry, Douglas, Jackson, Josephine, Lane & Linn counties;

Northcentral (NCOR) = Gilliam, Hood River, Morrow, Sherman, Umatilla & Wasco counties; Central (CEOR) = Crook, Deschutes, Grant, Jefferson & Wheeler counties;

Southcentral (SCOR) = Klamath and Lake counties; Northeastern (NEOR) = Baker,

Union & Wallowa counties; Harney County (HARN); and Malheur County (MALH). Ten counties of northwestern Oregon with no known NAs were not included in a region.

Simple Chi-Square tests were used to test frequencies for differences between years and regions. Statistical results were considered significant at (p<0.05).

Productivity (young per year occupied with known outcome) was determined for each nesting area. Productivity values for nesting areas with ≥5 years occupation with known outcome were arranged in a histogram to determine the statistical distribution of productivity results for that population. Locations for the individual nesting areas in that population were mapped to show their geographical distribution in the state.

Annual nesting success for nesting areas within 8 km (5 mi) of Malheur National

Wildlife Refuge (MNWR) boundary were compared to nesting success reported for nesting areas on and adjacent to MNWR from 1966–1998. Annual nesting success also was compared for nesting areas within 8 km (5 mi) of the refuge and nesting areas 8–16 km (5–10 mi) from the refuge boundary.

18 Nesting parameters from this study were compared to similar results from other studies in Oregon and other regions of western North America. Duration, number of nesting areas observed, and protocol varied widely between projects. The variables compared were occupation rate, nesting success, productivity, and brood size.

Nests were entered in 2012 and 2013 to band eaglets and train climbing teams.

Nests were selected based on locations and nestling ages observed during field work.

Banding followed the draft revision of the U.S. Geological Survey North American Bird

Banding Manual, Volume 1 (U.S. Geological Survey 2011), the North American Banding

Council’s Study Guide (North American Birding Council 2001), the HawkWatch

International Banding Manual (HawkWatch International 2011), banding techniques discussed by Varland (2007), and nest entry protocol described by Pagel et al. (2007).

USFWS leg bands were closed with stainless steel rivets per recommendation of the band manufacturer. Photos, GPS coordinates, and nest access directions were recorded at each banding location. Band information was entered into the USGS Bandit software program (U.S. Geological Survey 2012).

In 2014, nests were entered as part of a lead exposure study in cooperation with

U.S. Geological Survey, U.S. Fish and Wildlife Service, and the High Desert Museum. In addition to banding eaglets that year, blood samples were collected and ten eaglets were equipped with 45 gram Argos/GPS Platform Terminal Transmitters (PTTs, also referred to as satellite transmitters, from Microwave Technology, Inc.). Details on those ongoing projects will be reported by others (David Leal, USFWS, Portland, OR, personal communication).

19 RESULTS

Distribution - From 2011–2018, 1,018 golden eagle nesting areas have been documented in Oregon (Figure 2). Historical, confirmed golden eagle NAs reported before 2011 (Figure 2, n = 577) occurred in all but 12 counties in Oregon. Historical NAs

were concentrated in areas where personal interest or local resource management required knowledge of golden eagle nest locations. For example, amateur banding projects in Deschutes, Jefferson, Crook, Union and Baker counties; management of impacts of recreation along the Deschutes River in Sherman, Gilliam and Jefferson

20 counties; Malheur National Wildlife Refuge research and management in Harney

County; hydroelectric project dam re-licensing in Jefferson and Wasco counties; and surveys around proposed and existing wind power projects in Wasco, Sherman, Gilliam,

Morrow, Umatilla, Deschutes, Union, Baker and Harney counties. Most other historical

NAs were recorded during local surveys by resource management agencies, or incidentally during other field work or outdoor activities. Since 2010, 701 of 752 historical NAs (93%) have been observed while 51 (7%, n = 752, Figure 3) have not

been inventoried because of difficult or restricted access. Evidence of golden use

(eagles or nests) was found at 577 of 701 (82%) of historical NAs observed, and no

21 nests or eagles were observed at 124 of 701 historical NAs (18%) observed at least once.

During 2011–2018, 441 previously unreported NAs (Figure 2) were discovered during field work for this study, targeted surveys for proposed energy-related projects, field work for northern Great Basin golden eagle nesting habitat model testing (Brian

Woodbridge, USFWS-Western Golden Eagle Team, Corvallis, OR), and incidentally by outdoor enthusiasts and resource managers. The 441 recently discovered NAs fell within the historical distribution of golden eagle nest locations, and increased in-county nesting density in all but six counties with historical nest records (Clackamas, Lane,

Coos, Curry, Josephine and Hood River). As of 2018, there were 1,193 NAs listed for

Oregon that occurred in all but 10 northwest counties. Since 2010, 1,018 NAs (577 historical + 441 recently reported) have been verified in Oregon. Distribution of those

NAs includes all but 14 western Oregon counties (Clatsop, Columbia, Tillamook,

Washington, Multnomah, Yamhill, Lincoln, Polk, Marion, Benton, Lane, Coos, Curry and

Josephine) and one eastern Oregon county (Hood River).

In general, most golden eagle nesting areas are east of longitude -121°W, which roughly divides the state in half, north to south (Figure 4). That distribution contrasts with bald eagle nesting areas documented through 2010 (Isaacs & Anthony 2011), which mostly were located west of -121°W (Figure 4). There were notable exceptions for both species, with golden eagles nesting on the east side of the Willamette Valley and in southwestern Oregon, and bald eagles nesting near permanent water bodies throughout eastern Oregon (Figure 4). There are many areas in the state where the two species nest in close proximity.

22

Nesting Area Listing, Occupation and Nesting Success - Number of golden eagle

NAs first listed by year ranged from 0 for many years to 117 in 2011, with the cumulative total increasing notably during 1940, 1965–67, 1978–80, 1992, and 2010–16 (Figure 5).

As of 2018, there were 1,018 confirmed golden eagle NAs listed for Oregon, comprised of 577 historical NAs (57%), and 441 NAs added during 2011–2018 (43%,

Figure 3). The raw number of NAs listed, observed, occupied, and successful, and the number of eaglets counted annually show an upward trend that has slowed or decreased recently (Figure 6). Mean annual occupation rate was 58% (range 52%–

23 62%) and mean annual nesting success was 59% (range 45%–71%, Table 2).

24 One-thousand-eighteen NAs were observed at least one year during 2011–2018.

Eight-hundred-five (79%) of those were occupied at least once while 213 (21%) were never occupied. Occupation at least one year increased with number of years observed from 46% when observed one year (n = 78) to 94% when observed eight years (n =

254, Figure 7). Nesting success was observed at least once at 613 nesting areas with

25 known outcome (84%, n = 732) while success was never recorded at 119 (16%). As with occupation, nesting success at least one year increased with number of years observed from 58% when nesting outcome was known one year (n = 144) to 97% when outcome was known eight years (n = 37, Figure 7).

Statewide, nesting success varied by year and region. By year, nesting success ranged from 71% in 2011 (n = 197 nesting areas occupied with known outcome) to 45% in 2013 (n = 295). Nesting success was significantly more than expected in 2011

(p<0.025) and 2012 (p<0.05) and less that expected in 2013 (p<0.005) and 2018

(p<0.05). Nesting success in 2014 was less than expected, and in 2015, 2016 and 2017 was greater than expected, but not significantly so (Figure 8). By region, nesting

success ranged from 51% in Central Oregon (n = 649 nesting areas occupied with known outcome) to 67% in Harney County (n = 497). Nesting success was significantly

26 less than expected in Central Oregon (p<0.025) and significantly more than expected in

Harney County (p<0.025). For the other regions, nesting success was more than expected in Western Oregon, Northcentral Oregon and Malheur County, and less than expected in Southcentral Oregon and Northeastern Oregon, but not significantly so

(Figure 9).

Ownership - Bureau of Land Management (52%, n = 2,677) and private land owners

(30%) accounted for 82% of golden eagle nest locations in Oregon. U.S. Department of

Agriculture, mostly U.S. Forest Service) held 10%, U.S. Fish and Wildlife Service had

3%, and State of Oregon and Bureau of Reclamation had 2% each. The remaining 1%

(29 nest locations) were distributed among Bureau of Indian Affairs (17), National Park

Service (7), and U.S. Army Corps of Engineers (5, personal communication, Larry

27 Reigel, U.S. Fish and Wildlife Service, Oregon Field Office, Portland, Oregon).

Nest Substrate - Nest substrate for the first nest located in a NA was recorded for 995

NAs through 2018. Nests were built on cliffs (755, 76%), in trees (220, 22%), and on electricity transmission line towers (pylons, 20, 2%). Distribution by substrate appeared to reflect availability, but that was not tested statistically. In general, tree nests occurred where forests were more common than cliffs and cliff nests occurred where cliffs were abundant and trees were scarce or nonexistent (Figure 10). Number of nests in trees

and on pylons were probably under-represented because tree nests were harder to locate and power line corridors were not surveyed thoroughly due to restricted access.

28 Within NAs, tree nests tended to occur singly whereas cliff nests tended to occur in groups, resulting in more cliff nests per nesting area than tree nests per nesting area.

Several NAs contained nests on more than one kind of substrate.

Nesting Phenology - Nesting phenology (Figure 11) was based 478 successful nesting

attempts, 2011–2014, where eaglets were aged to the closest week of age, and site- specific nesting chronology was estimated. Egg laying and incubation began during the seven-day period of 29 January to 4 February, peaked during 26 February–3 March, and ended during 1–7 April. That ten-week period of egg laying resulted in the nesting period for golden eagles in Oregon lasting from late January to early August. Hatching peaked during 8–14 April, the majority of eaglets were 1–3 weeks old 22–28 April, the number of 4–7-week-old nestlings peaked during mid May, and 8–10-week-old eaglets were most abundant during mid June. Early nesting was based on 13 chronologies (3%, n = 478) with egg laying during 29 January–11 February and late nesting was the result

29 of 11 chronologies (2%, n = 478) with egg-laying during 25 March–7 April, including one that may have been the result of re-nesting. Consequently, 95% (n = 478) of egg laying occurred during the 6-week period of 12 February–24 March (Figure 11).

Monitoring Results - Annual occupation rate averaged 58% (Table 2, range 52–62,

Figure 12) and nesting success averaged 59% (range 45–71, Figure 12). Productivity

was 0.81 eaglets per occupied breeding area with known outcome (range 0.63–1.04,

Figure 13), and brood size averaged 1.38 young per successful nesting attempt (range

1.28–1.46, Figure 13).

Minimum population and production estimates were based on annual percent

30 occupied and young per occupied NA with known outcome (Table 2). Mean minimum estimated statewide nesting population was 589 nesting pairs (range 533–632) and mean minimum estimated production was 486 eaglets per year (range 346–619, Table

2).

Through 2018, 278 golden eagle NAs in Oregon have ≥5 years of occupation with known nesting outcome (Figure 14). Statistical distribution of productivity (young/ year occupied with known outcome) for those NAs approached Normal (Figure 15).

2011-2018 annual nesting success for areas within 8 km (5 mi) of the MNWR boundary ranged from 37.5% (n = 8) in 2013 to 90.5% (n = 21) in 2016. Both the minimum and maximum nesting success during 2011-2018 were greater than what was reported for 1966–1998 (Figure 16). Nesting success for NAs within 8 km (5 mi) and

31 NAs 8–16 km (5–10 mi) had similar trends during 2011–2018, however there was a greater decline in the 8–16 km group than for the <8 km group in 2018 (Figure 17).

In general, nesting parameters for golden eagles in Oregon during 2011–2018 were within the ranges reported for other studies in Oregon and other western states

(Table 3). Occupation rate was lower than all but one study; nesting success was second highest among the reports; productivity was near the center of the range and brood size was at the low end of the range.

32 33 34 Nest Entry - In 2012 and 2013, 26 eaglets from 17 nests were banded between 15 and

30 May (Appendix 4) when most eaglets were 4–7 weeks old (Figure 11). In 2014, 76 of

80 eaglets at 53 nests were banded between 26 April and 12 June when eaglets were

3–8 weeks old (Figure 11) and 10 were equipped with satellite radio transmitters at 7–8 weeks of age (PTTs, Appendix 4). Post-banding observations were conducted at 53 breeding areas prior to suspected fledging dates. Sixty-nine of 80 banded eaglets were alive (86%), 4 were dead (5%), and 7 were not accounted for (9%), resulting in a maximum nestling (pre-fledging) mortality rate of 14%. Based on observations and limited testing of birds that died between nest visits or while being monitored; one died due to suspected siblicide, one died due to rodenticide exposure, and two died of unknown causes. One of two that died of unknown causes was the sibling of the eaglet with confirmed rodenticide poisoning and may have succumbed to rodenticide exposure as well. To date, there have been two post-fledging band returns (Appendix 4); one captured and released unharmed near Prescott, Arizona and one electrocuted near

Crane, Oregon.

As of 4 March 2017, eight of ten radioed nestlings either died or had shed their transmitters after fledging (Appendix 4). Only one dead radioed juvenile was recovered but cause of death was unknown. One transmitter was not functioning properly and therefore the fate of that juvenile was unknown. By February 2018, all ten transmitters had ceased functioning (David Leal, USFWS, Portland, OR, personal communication).

35 DISCUSSION

Gabrielson and Jewett (1940:195) recorded golden eagles in Oregon every month of the year and in every eastern Oregon county except Jefferson and Sherman through

1935. They did not quantify golden eagle abundance, however they categorized the species as “rare” west of the Cascades and “...a common breeding species and permanent resident” of eastern Oregon. The population of golden eagles in Oregon circa 1970 was estimated at 1,600 individuals, minimum (Heugly 1973 in Snow 1973), however the basis for that estimate was not explained. Isaacs and Opp (1991) summarized data on nest locations reported in Oregon through 1982 and estimated that at least 500 nesting pairs occurred in the state. Carey (2003: 161) categorized the species as a “…common to uncommon year-round resident in all counties east of the

Cascade Range”, and reported that the population trend in the state was unknown

(Carey 2003:162). Results from this study suggest a minimum of 526 nesting pairs in the state based on 1,018 confirmed nesting areas listed in 2018 (Table 2).

Analysis of nesting area occupation based on number of years observed and occupation at least one year, revealed that proportion occupied increased from 46% (n

= 78) to 94% (n = 254) as number of years observed increased from one to eight

(Figure 7). Those rates for three to eight years observed were higher than the average annual occupation of 58% (range 52–62%, Table 2), suggesting that the actual annual occupation rate was greater than what was observed, and that multiple years of monitoring improve knowledge of nesting area use, population size, and distribution.

Similar analysis for nesting success revealed that success at least once was observed at 58% (n = 144) of nesting areas where outcome was determined one year,

36 and increased to 97% (n = 37) when outcome was determined eight years (Figure 7).

Annual nesting success averaged 59% (range 45%–71%, Table 2), which was lower than when nesting outcome was determined 2–8 years (Figure 7). Those results reveal that multiple years of determining nesting outcome are required to evaluate the potential for a nesting area to support successful nesting by golden eagles.

First year of record for golden eagle nesting areas in Oregon ranged from 1875 to 2018 (Figure 5). Peaks in annual number of first reports occurred in 1940, 1967,

1980, 1992 and 2011. Each of those years corresponded to a spike in interest in golden eagles in Oregon prompted by a research project or event. In 1940, Scharff and Groves

(1940) first reported on golden eagles nesting around MNWR. In 1965, Hickman (1968) requested statewide reports on golden eagle nest locations. Bald eagles (Haliaeetus leucocephalus) were listed federally as a threatened species in Oregon in 1978 prompting interest in both species and culminating in the 1980 peak of first reports.

Isaacs & Popp (1994) solicited statewide nest locations in 1992. Finally, Isaacs (this study) requested statewide nest locations in 2010, resulting in the 2011 peak. The cumulative record of nest locations (Figure 5) at least signifies the increase in human interest in the species, and might be an indirect indication that the nesting population has increased since a suspected low point in the mid 1900s.

Some areas of the state have not been searched thoroughly for golden eagle nests, including northwest Oregon and portions of eastern and southwestern Oregon

(~blank areas of Figure 2). Areas of eastern Oregon without historical (pre 2011) locations that were searched during 2011–2018 contained many previously undocumented NAs (Figure 2). In addition, Jim Harper (Medford, OR, personal

37 communication) reported that the number of NAs in southwestern Oregon probably is under-represented due to the difficulty of finding nests in dense stands of trees in rugged terrain with limited access. Consequently, future field work in un-surveyed areas could result in addition of many (>100) previously unknown NAs statewide and a corresponding increase in the minimum known and estimated statewide populations.

The lack of historical nest locations in northwest Oregon (Figure 2) may be because open habitat preferred for hunting by golden eagles in that area was settled by

Oregon Trail pioneers in the mid 1800s (Loy et al. 2001:28). Settlement resulted in agricultural development (Loy et al. 2001:94), increased human population, extensive road building and urbanization (Loy et al. 2001:104), and unregulated predator control that lasted at least until 1972 (deCalesta 1976). As a result, nesting golden eagles probably were extirpated from northwest Oregon before nest locations were recorded.

During 2011–2018, three golden eagle NAs were occupied and at least eleven eaglets were produced in the western foothills of the Cascade Mountains east of the Willamette

Valley (this study). There appears to be abundant habitat in northwest Oregon for increased size and expanded distribution of the golden eagle nesting population in that area. Recent observations of adult golden eagles during the nesting season in northwest Oregon reported by Oregon Birders On-Line ( http://www.orbirds.org/ obolarchives.html ), and East Cascades Audubon Society Winter Raptor Survey

( https://www.ecaudubon.org/winter-raptor-survey ) suggest that there may be unreported or undiscovered golden eagle nests in that part of the state.

Macro spatial characteristics of golden eagle nest locations reported through

2012 were analyzed by Anderson (2013) as part of an advanced Geographic

38 Information Systems (GIS) class at University of Washington. Those analyses indicated that nest locations were clustered rather than random on the landscape. Parameters that influenced clustering of nest locations were distance to a major hydrological feature, land cover type, elevation, slope, land features and average annual precipitation. Distance to roads and aspect did not appear to influence nest location.

These results provide insight into nest site selection and exhibit the potential for future extensive GIS analysis of survey results.

Statewide reproductive statistics herein are the first such data reported for

Oregon (Table 2). Nesting success ranged from 45% in 2013 (n = 295) to 71% in 2011

(n = 197, Table 2). Nesting success was significantly higher than expected in 2011 and

2012, and significantly lower than expected in 2013 and 2018 (Figure 8). Significant differences between years suggest that environmental conditions can affect nesting over large areas during a single year, and that there can be significant changes from one year to the next, e.g. 2012 nesting success was significantly higher than expected and 2013 was significantly lower (Figure 8).

Somewhat comparable nesting parameters have been reported for regions within

Oregon and for populations in other states (Table 3), including results of statewide nest surveys conducted in Washington during 2013 and 2014 (Hayes 2014). Percent occupied and brood size for Oregon during 2011–2018 were comparatively low, while nesting success and productivity were similar to results from other areas. These data should be interpreted with caution because of differences in terminology and protocol between studies. In addition, the Oregon results may have biases related to coverage, technique or timing. For instance, occupation rate may be underestimated because

39 four-hour monitoring protocol (Pagel et al. 2010:10) was not followed. As a result, population size may be underestimated and nesting success and productivity overestimated because occupied breeding areas where nesting did not occur or failed early may have been missed.

Regional (within state) occupation and nesting success are likely to show wider annual or periodic variation than statewide results due to local conditions, especially weather and changes in prey abundance. Results from 1966–1998 monitoring of breeding areas on and around MNWR suggested ~10-year cycles of nesting success

(Figure 16) based on jackrabbit population cycles (1966–1980 data from Thompson et al. 1982, 1981–1998 data from MNWR files, Refuge Headquarters, Princeton, OR).

Unfortunately, monitoring was not conducted from 1999–2010. Recent results for the same general area (Figure 16, 2011–2018) are less clear, however the short survey period (8 years), and differences in monitoring personnel, technique and terminology make direct comparisons of nesting success rates difficult.

Results of surveys in Harney County in 2014 and 2018 exemplified a wide range in nesting success by region within one year. In 2014, nesting success in the east 1/2 of the county was 49% (n = 49), and in the west 1/2 of the county was 75% (n = 24). In

2018 nesting success for NAs within 8 km of MNWR was 50% (n = 20) and for NAs 8–

16 km from the refuge nesting successs was 22% (n = 9, Figure 17). Similar uneven distribution of successes and failures were suspected annually in other parts of the state. Annual statewide results reported herein (Table 2) probably are comprised of wider-ranging, sub-population fluctuations which better reflect local and regional differences in golden eagle nesting success, e.g. prey abundance, weather, human

40 disturbance, etc.

Examining area-based trends in golden eagle nesting success requires monitoring multiple nesting areas within defined regions for multiple consecutive years as was done at MNWR. Groups of ten or more nesting areas with five or more consecutive years of monitoring, and outcome determined for at least five nesting areas per year may be a minimum threshold to provide meaningful results. In 2018, 278 nesting areas in Oregon met the threshold of having five or more years of known nesting outcome during 2011–2018 (Figure 14). The distribution of those nesting areas indicates regions suitable for regional trend analysis. With each additional consecutive year of monitoring, more nesting areas will meet the five-year-known-outcome threshold, increasing the potential for regional analyses on smaller scales. For 2018, seven regions were delineated to show regional trends within Oregon (Figure 9).

Results show similarities and differences between regions and exemplify the potential for regional analyses. For example, for 2011–2018 Central Oregon had significantly lower nesting success than expected (p<0.025, Figure 9), and Harney County had significantly greater nest success than expected (p<0.025, Figure 9).

Re-nesting may have occurred in Oregon in 2013 at a breeding area along the

Crooked River. An adult golden eagle was observed in incubating position on a nest on the east side of the river on 18 April, then a 1–2-week-old-eaglet was found on a nest

~170 m away from the original nest directly across the river on 5 June. Pseudo- incubation can’t be ruled out for the 18 April observation because an egg was not observed. However, the 1–2-week-old eaglet on a different nest on 5 June was extremely late and may have been the result of re-nesting. Watson (1997:143)

41 suspected re-nesting in 2 of 200 nesting attempts by golden eagle pairs in Scotland and re-nesting occurred in 2 of 674 nesting attempts in southwest Idaho (M. Kochert, USGS-

FRESC, Boise ID, personal communication). Some of the late-nesting records for

Oregon (Figure 11) may have been the result of re-nesting.

Trend in the size of the golden eagle population in western North America is uncertain. The trend has been reported as “declining” based on long-term surveys

(Kochert et al 2002:26, Pagel et al 2010:4) and “not declining widely” based on late- summer aerial transects conducted during 2006–2010 and Breeding Bird Surveys from

1968–2005 (Millsap et al 2013). Both conclusions may be accurate because they are based on different techniques, population segments, and time periods.

In Oregon, the trend in size of the nesting population also is uncertain. Anderson

(1985) surveyed 20 breeding areas in central Oregon from 1965–1984. During that period, the occupation rate declined from 100% in 1966 (n = 13), to 50% in 1977 (n =

14), and 25% in 1983 (n = 20). Suspected causes of that decline were reduced prey

(especially jackrabbits), increased human activity (especially off-road recreation and rodent shooting), and habitat change (especially loss of “old-growth” trees). However, that research was conducted in a relatively small area with relatively high human activity and was based on a small sample of breeding areas (n = ≤20). Isaacs & Opp’s (1991) estimate of a minimum of 500 nesting pairs in the mid 1980’s is lower than the 2011–

2018 result based on historical nest locations (577 confirmed historical NAs X 58% occupation rates from Figure 2 and Table 2, respectively = 335 nesting pairs) suggesting that estimate may have been high for the 1980s. In contrast, the 441 previously undocumented NAs discovered in Oregon during 2011–2018 could indicate

42 that the statewide nesting population is increasing and expanding. However, that conclusion may be incorrect because all but one of those “new” NAs probably existed prior to 2011. Only one nesting area was known to have been established during 2011–

2018.

Anecdotal evidence and results of this study suggest that the breeding population of golden eagles in Oregon experienced long-term decline from circa 1800 to the mid

1900s due to predator control and habitat loss, increased from the mid-1900s to circa

2000, and has been slowly increasing or stable since. Current inventories of golden and bald eagle nest locations indicate that much of Oregon is now within the home range of a nesting pair of either or both eagle species (Figure 4). Consequently, land and resource managers should consider eagles and eagle habitat management in land and resource use planning, especially where eagles are known to be breeding within 16 km

(10 mi) of a project area. In addition, monitoring should be conducted over multiple years because the probability of occupation increases with the number of years observed (Figure 7).

Three-hundred-forty wild golden eagles were banded in Oregon from 1955 to

2013 (Leal 2016, Appendix 5). Thirty-five bands (10.3%) were subsequently encountered and 34 included reliable recovery locations. Twenty-six (76%) were recovered in Oregon, three were in California (8.8%), and there was one each (2.9%) from Nevada, Washington, Arizona, Saskatchewan, Canada, and Baja Del Norte,

Mexico (Appendix 5). Eagles banded in other states have been encountered in Oregon, including five from California, four from Idaho, three from Washington, and one each from Montana and Nevada. In addition, recent satellite telemetry has tracked Alaskan

43 eagles to Oregon, and Oregon eagles to Idaho, Wyoming and Utah (Appendix 5).

Age at death was known for 24 hatch-year eagles banded in Oregon and ranged from 4.5 months to 23 years, 8.4 months (Appendix 5). Six (25%) died within their first year, 14 (58%) died within 2 years, 8 (33%) lived longer than 4 years, and 4 (17%) lived longer than 8 years (Appendix 5).

Golden eagles banded in Oregon dispersed in a variety of directions and distances. However, none dispersed west across the Cascade Mountains (Appendix 5).

Dispersal distance for seven banded golden eagles encountered as adults (5–23 years old) ranged from 11.3 to 1,586 km (7 to 986 miles) with a mean distance of ~259 km

(161 miles) and median distance of 39.4 km (24.5 mi, Appendix 5). The median natal dispersal distance was similar to that reported by Millsap et al. (2014) for golden eagles across the contiguous western U.S (Appendix 5).

Two of 102 golden eagle nestlings banded in Oregon during 2012–2014 have been reported (2% recovery rate, so far). The first, banded at a nest near Drewsey,

Oregon on 25 May 2013 was captured near Prescott, Arizona on 22 December 2013.

That bird was released in Arizona after it was determined that it was healthy (The Daily

Courier, Prescott, AZ, 7 January 2014). The second was one of two nestlings banded at a nest near Crane, Oregon on 16 May 2013 and found electrocuted on 7 March 2014

~1.15 km (0.71 mile) from the banding location (G. Herring, Corvallis, OR, personal communication).

Banding can provide valuable information on movements, longevity and causes of death. However, low recovery rates mean that hundreds of birds need to be banded.

In addition, results are slow to accumulate, requiring a long-term commitment. Even

44 with a large sample of recoveries, locations may be biased towards areas frequented by humans (e.g. road corridors, settlements and agricultural areas) and causes of death biased towards human causes (e.g. shooting and electrocution), resulting in incomplete and biased results (McIntyre 2012). Consequently, researchers need to be aware of inherent biases when evaluating banding results. There have been no reports of bands from the 2014 cohort of 76 nestlings (Appendix 4). Results of ongoing contaminant and telemetry studies will be reported elsewhere by USGS and USFWS (Garth Herring,

USGS, Corvallis, OR, and David Leal and Jeremy Buck, USFWS, Portland, OR personal communications).

Historical golden eagle banding and ongoing telemetry have shown that golden eagles, especially non-breeders, move long distances and travel to and from Oregon from most western states, western Canada and Mexico. Once they reach breeding age they wander less and tend to join nesting populations in the vicinity of their natal area.

These results are similar to the movements and nesting habits reported for bald eagles nesting in Oregon (Isaacs & Anthony 2011).

45 RECOMMENDATIONS

1) Continue to review and compile historical records – Historical (pre 2011) records of golden eagle nest locations provided the starting point for this project. Gathering and compiling historical records is ongoing.

2) Continue to inventory historical locations – Ninety-three percent of historical breeding areas (n = 752) were inventoried during 2011–2018. The remaining 7% of historical locations (51) should be inventoried if possible.

3) Expand searches for “new” nests in likely habitat – During 2011–2018, 441 previously unreported golden eagle NAs were documented. Those were discovered by searching likely habitat >3.2 km (>2 mi) from known nest locations. Similar nest searches should continue.

4) Increase monitoring – Monitoring should include as many NAs as possible. However, inadequate monitoring (NAs visited but nesting status not determined) is an inefficient use of time and resources. Cooperators should be encouraged to determine nesting outcome at as many sites as possible.

5) Improve monitoring – Nesting outcome has been determined at 50% of nesting areas observed (Table 2, n = 5,523). Determining outcome at a greater proportion of nesting areas would improve confidence that the reproductive statistics accurately represent the population.

6) Establish long-term monitoring goals, routes and protocols – Attempting to monitor all breeding areas is valuable to refine technique and timing, determine accurate baseline population and reproductive statistics, and provide input to resource managers on short notice. However, large-scale monitoring won’t continue indefinitely. Consequently, establishing long-term monitoring goals and protocols should be done in cooperation with resource managing agencies.

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Thompson, S. P., R. S. Johnstone, and C. D. Littlefield. 1982. Nesting history of golden eagles in Malheur-Harney lakes basin, southeastern Oregon. Raptor Research 16:116-122.

51 U.S. Fish and Wildlife Service. 2009. Final Environmental Assessment, Proposal to Permit Take as Provided Under the Bald and Golden Eagle Protection Act. U.S. Fish and Wildlife Service, Division of Migratory Bird Management, Arlington, VA, USA. https://www.fws.gov/alaska/eaglepermit/pdf/environmental_assessment.pdf

U.S. Fish and Wildlife Service. 2010. North American Golden Eagle Science Meeting: A collaborative critique of the golden eagle’s uncertain future in North America (minutes and notes), 21 September 2010, U.S. Geological Survey Science Center, Fort Collins, Colorado, USA.

U.S. Geological Survey. 2011. Bird Banding Lab. DRAFT revision of the North American Bird Banding Manual V. 1. Available in electronic format only. http://www.pwrc.usgs.gov/bbl/manual/manual.cfm

U.S. Geological Survey. 2012. Bird Banding Lab. Bandit: The Information Manager for Banding Operations. v 3.01. http://www.pwrc.usgs.gov/bbl/ resources/bandit/index.cfm

Varland, D. 2007. Marking Techniques. Pages 221-234 in Raptor Research and Management Techniques. Raptor Research Foundation.

Watson, J. 1997. The Golden Eagle. T & AD Poyser Ltd, London, England.

52 Appendix 1. People and organizations other than major funders that contributed to the golden eagle nest survey project in Oregon during 2011–2018. Some individuals made multiple contributions, e.g. working for an agency and volunteering their personal time.

First Name Last Name Affiliation

N Adams USFS Rich Adney Volunteer R Ahrens Volunteer Glenda Alm Volunteer Terri Andersen USFS Bob Anderson OEF Brett Anderson NWC & Volunteer Caleb Anderson Volunteer David Anderson OEF David Anderson The Peregrine Fund Dean Anderson Volunteer Evelyn Anderson Volunteer Jim Anderson Natural Selection & Volunteer Joseph Anderson Volunteer Kris Anderson Volunteer Missy Anderson Volunteer Ralph Anderson Volunteer Ross Anderson Volunteer Sam Anderson Volunteer Sue Anderson Natural Selection & Volunteer Suzanne Anderson USFWS Tyler Anderson Volunteer _group_ Anderson Family Volunteers Steve Andrews Volunteer Christopher Anthony BLM John Anthony USFS George Arnold Volunteer Larry Ashton BLM Tom Athens USFWS Joe Atkinson Volunteer Forrest Babcock Volunteer Dave Babonis Volunteer Joe Baer USFS Climber Bob Baker Volunteer Gayle Baker Volunteer Greg Baker Volunteer Jerry Baker WEST Inc. Mary Baker Volunteer Chancy Ball Volunteer Morgan Bancroft Volunteer Paul Bannick Volunteer Stephanie Barclay Volunteer Donna Barton Volunteer Ken Bastian Volunteer Charles Baughman Volunteer Doug Beall Volunteer Lew Becker Volunteer Kelly Behne Volunteer Florian Bell Volunteer Beth Bellinger BPA Tim Bemrose BLM

Appendix 1 1 Kent Benesch BLM Dalhia Bennett Volunteer Dennis Bennett Volunteer Maryha Bennett Volunteer Andy Bidwell PGE Craig Bienz TNC Bing Bingham Volunteer Frank Bird Volunteer Karla Bird Volunteer Shawn Bishop BLM Kirsten Bixler OSU Gary Blagg BLM Jamie Blankenship Volunteer Peter Bloom Bloom Biological Tim Blount Volunteer Joseph Blowers Volunteer Arlene Blumton USFS Lucas Bobay USFWS Intern Kim Boddie Volunteer Tim Bodeen USFWS Ashley Boeckx Volunteer Mike Bohannon USFS & Volunteer Barbara Bohm-Becker Volunteer Kristi Boken PGE Theresa Bolch BLM Darren Bolen BLM Ryan Bonner Alcoa Fastening Systems Shelley Borchert USFS Katie Boula Volunteer Graham Boverman Volunteer Jay Bowerman Volunteer Wayne Bowers Volunteer Darrell Breckel Landowner Ryan Brennecke Bend Bulletin Jason Brewer BLM Cindy Bright BLM Andrew Broadhead USFS Jerry Broadus Volunteer Camille Brooks USFS Paula Brooks Volunteer Betsy Brown Volunteer Chase Brown ODFW Elise Brown BLM Kimberley Brown Volunteer Leland Brown Oregon Zoo Rebeca Brown-Thompson Volunteer Matt Broyles BLM Charlie Bruce Volunteer Camden Bruner BLM Jeremy Buck USFWS Bill Burkett Volunteer Stacy Burleigh Audubon Diane Butler Volunteer John Butler Volunteer Bart Butterfield Volunteer Jeff Butts Volunteer Diana Byrne Volunteer Jim Cadwell ODFW Matt Cahill Volunteer Ian Caldwell OPRD Rick Callahan USFS

Appendix 1 2 Doug Calvin CTWS Matt Cambier Tetra Tech & URS Corporation Karen Cardin Volunteer Chris Carey ODFW & Volunteer Joyce Carnes Volunteer Scott Carpenter Volunteer Teri Carrigan Volunteer Tim Carrigan Volunteer Kim Carson Volunteer Cheran Cavanaugh USFS Michelle Caviness BLM Caleb Centanni Volunteer Ann Chamberlain Volunteer Steve Cherry ODFW Brenda Chilson Volunteer Janel Christman Volunteer Greg Ciannella OPRD Samantha Cisney BLM Rita Claremont Volunteer Catherine Clark BLM Rynda Clark Volunteer Steve Clark Volunteer Peggy Clement Volunteer Mike Clifton Volunteer Gary Clowers Raven Research & Volunteer C Cobos USFS Ron Coleman ODFW M Colletti BPA Gail Collins USFWS Maddie Collins Volunteer Pam Comeleo Volunteer Randy Comeleo Volunteer Devon Comstock ONDA Greg Concannon Portland General Electric Dian Connett Volunteer Mary Coolidge Volunteer Jeff Cooney Volunteer Sylvia Copeland Idaho Power Bileanne Cordier USFS Jerry Cordova USFWS Hilary Corrigan Bend Bulletin Jim Cota Volunteer Rick Craiger USFWS? Dan Crannell BLM Clay Crofton Volunteer Stuart Croghan Volunteer Harvey Cronin Volunteer Patsy Cronin Volunteer Toby Cronin Volunteer Summer Cross BLM Carter Crouch Burns Paiute Tribe Ron Crutchley BLM _group_ CTWS Warm Springs Reservation Kathleen Dalke Volunteer Peter Dalke Volunteer Dylan Darling Bend Bulletin Jim Dastyck USFWS Tony Davis Landowner Bill Dean BLM Steve DeBerry Dry Cr Landfill Peter DeJongh BLM

Appendix 1 3 Elise Delgado USFS Kan Dhillon BLM Jeff Dillon USFWS Mike Dirkson Oregon Zoo Volunteer Rob Domenech RaptorView Sage Dorsey Volunteer Steve Dougill Volunteer Dean Draper Volunteer Don Dryer Volunteer Jessie Dubuque USFS Katy Duffy Volunteer Gabe Dunham Volunteer Janine Dwyer Raptor Rehab Collin Eagles-Smith USGS Judy Eaton Volunteer Michael Edwards USFS Steve Edwards Volunteer Deanna Emig Volunteer Steve Engel Audubon Society of Portland Terry Enk WEST Inc. Calvin Erickson ODFW Leonard Erickson ODFW Roli Espinosa BLM Jeff Everett USFWS Louisa Evers Volunteer Jim Fairchild Volunteer Mary Fay Volunteer _group_ FBI Federal Bureau of Investigation Dan Fenske Volunteer Cheron Ferland USFS Dorothy Fern Volunteer (landowner) Mike Fern Volunteer (landowner) Brian Ferry ODFW Jeff Fields TNC Nick Fisher OPB Robert Fisher Landowner Thad FitzHenry Portland General Electric Cathy Flick USFS & Volunteer Ernie Fliegle BLM Ralph Foote Volunteer Sherri Foote Volunteer Todd Forbes BLM Eric Forsman Volunteer Craig Foster ODFW Ralph Fox Volunteer Toni Fox Volunteer Lowell Franks Volunteer Roger Freeman Volunteer Anne Frost USFS Carol Fuchs Volunteer Jerry Fuchs Volunteer Georgina Fugate Volunteer Ken Fukuda BLM Zia Fukuda BLM Harry Fuller Volunteer June Galloway USFS & Volunteer Chuck Gates Volunteer Elizabeth Gayner BLM Joel Geier Volunteer Karen Gentry Volunteer Robert Gentry USFS

Appendix 1 4 Aurora Gerhardt Volunteer Jasper Gerhardt Volunteer Nathan Gerhardt Volunteer Renuka Gerhardt Volunteer Rick Gerhardt Sage Science, Inc. & Volunteer Ralph Gerig Volunteer Roy Gerig Volunteer Callie Gesmundo Volunteer ? Gill USFS Erin Gillett BLM Linda Gilpin Volunteer Shauna Ginger USFWS Betsy Glenn USFWS Jill Gleysteen Volunteer Steve Godwin BLM Sally Goebel Volunteer Mike Golden Volunteer ? Gonzalez Volunteer John Goodell High Desert Museum Carrie Gordon USFS & Volunteer Carey Goss USFWS Kim Gossen Volunteer Nunzie Gould Volunteer Jamie Granger Hamer Environmental George Grant Volunteer Joyce Green Volunteer Mike Green USFWS Monty Gregg USFS Corey Grinnell Volunteer H Grist USFS Bob Gritsky NWC Vianney Guzman Volunteer Linda Hadfield Volunteer Justin Hadwen USFS Christian Hagen ODFW Cindy Haggus Volunteer Linda Hale Volunteer Patti Hall OPRD Interpretive Volunteer Rae Hall OPRD Interpretive Volunteer Carole Hallett Volunteer Eric Hallingstad WEST Inc. Kelley Hamilton Volunteer Jim Hammond Volunteer Carole Hancock Volunteer Steve Haney BLM Jim Harper Volunteer Tom Harper Volunteer Jordan Harrison Volunteer Joel Harvey BLM Hans Hayden ODFW Patrick Hayden ODFW Dave Hayes Volunteer Steve Hayner BLM Diedre Hayward BLM Stephanie Hazen Volunteer Faye Healy USFWS Jim Heaney BLM Mary Jo Hedrick ODFW Chris Hein ABR Inc. Craig Heinrich BLM Erik Helms Slayden Construction Group

Appendix 1 5 Karl Helser Volunteer Brandon Henson BLM Hendrik Herlyn Volunteer Lotte Hermannsson Volunteer Stephen Hermannsson Volunteer Ben Hernandez USFS Davis Hernandez-Alvarez Volunteer Garth Herring USGS Connie Hewitt Volunteer Rick Hewitt Volunteer Marianne Hickson Volunteer Kimberly Higgs USFS Will High Volunteer Deborah Hill Volunteer Brett Hodgson ODFW Cliff Hoeft South County Helicopter Byron Hoeper Volunteer James Hoffman Volunteer Dustin Hollowell USFS Greg Holm NPS Toni Holthuijzen Idaho Power Andrew Hood BLM Jennifer Horsman Volunteer Cheryl Horton OSU Leah Hough PGE Richard Hoyer Volunteer J Huffine Volunteer Lance Hull Volunteer Dawn Hulton USFWS Bruce Hummel Volunteer Cassandra Hummel BLM Grainger Hunt Volunteer Terry Hunt Volunteer Matthew Hunter Volunteer Marcia Inscore Landowner Eric Isaacs Volunteer Frank Isaacs OEF & Volunteer Wren Isaacs Volunteer Sher'ri Jackson BLM Ed Jahn OPB Al Jamison Volunteer Erna Jamison Volunteer Dennis Jenkins UO Sacha Joachims BLM Thurman Johnson Volunteer Trisha Johnson USFS K Johnston BLM Justin Jones TNC David Journey Volunteer Jason Journey ODFW Jeff Kalin USFS Chad Karges USFWS Carol Karlen Volunteer Andrea Karoglanian CTWS J Keehn USFWS Matt Keenan ODFW George Keister Volunteer Marnie Keller BLM Isaac Kelsey BLM B Kerfoot BLM K Kerwin BLM

Appendix 1 6 Patsy Kestner Volunteer Scott Kestner Volunteer Monica Ketcham BLM Angie Ketscher Volunteer Ross Ketscher Volunteer John Keyser Volunteer Marilynne Keyser Volunteer Kevin Klatt BLM Jamie Knight ODF Michael Kochert USGS Bob Korfhage Volunteer Anne Kramer Volunteer Eben Krantz BLM Kenny Kreb Volunteer Miranda Kreb Volunteer Keith Kreuz Volunteer Lynn Kreuz Volunteer Sue Krieger Volunteer Karen Kronner NWC & Volunteer Monte Kuk BLM ? Kurtz USFS Kristi Lahusen Volunteer Jan Laird Volunteer Gary Landers Volunteer Chris Langdon BLM Rick Larcade Watermaster Candace Larson Audubon Society of Portland Chris Larson BLM Brian Laughlin ODFW Tom Lavagnino Volunteer Timothy Lawes OSU Tom Lawler Volunteer Leslie Lawrence Volunteer Mike Lawrence USFS Steve Lay Volunteer Jim Le Comte BLM Art Leal USFWS Volunteer David Leal USFWS Gabe Leal BLM George Lepp Volunteer Mark Lesko USFS Pete Lickwar USFWS Rob Linxwind Volunteer Miriam Lipsitz Volunteer Ted Lipsitz Volunteer Jim Long Volunteer Courtney Loomis Volunteer Glenn Lorton BLM Peter Low Volunteer John Luginbuhl USFS Lisa Lyon USFS Todd Mabee ABR Inc. Aaron Macy Raven Research Technician Rick Madigan ODFW Polly Maertz Volunteer Ron Maertz Volunteer Colleen Malaney USFS April Malone BLM Bonnie Mandish USFWS Volunteer Timmie Mandish USFWS Volunteer Tiffany Manger BLM

Appendix 1 7 Charles Manis Volunteer Melissa Manis Volunteer Robert Marheine Portland General Electric Gary Marshall Volunteer Georgia Marshall Volunteer Teri Martine Volunteer Alexa Martinez USFWS Jeff Marzal USFS Elizabeth Materna USFWS Alan Mauer USFWS Kevin Maurice USFWS Arch McCallum Volunteer Colin McCoy Volunteer Duke McDaniel Volunteer Sue McDougal Volunteer Kevin McGarigal Volunteer Brent McGregor Volunteer Josephine McKibbin Volunteer Stephanie McKinney BLM Ellie McNairy USFS Emma McNeil BLM Larry McQueen Volunteer Laura McShane Volunteer Reese Mercer Volunteer Judy Meredith Volunteer Marisa Meyer USFWS Steve Meyer ODF Andy Meyers USFWS Kara Michaelson Volunteer Lisa Mickelson Volunteer Rebecca Migala USFWS Al Miller Volunteer Gary Miller Volunteer Gary Miller USFWS Larry MIller Volunteer Nick Miller BLM Paul Miller USFS Sheri Miller Volunteer David Mims Volunteer Janna Mims Volunteer Erika Mittermaier BLM David Moen Nez Perce Tribe Ross Morrison Volunteer Marshal Moser Volunteer Laura Mountainspring Volunteer Jon Mousel Volunteer Jason Mowdy BLM Corbin Murphy BLM Bim Murray Volunteer Cindy Murray Volunteer Dick Musser Volunteer Nick Myatt ODFW Russ Namitz Volunteer Jim Narmoor Volunteer Laura Navarrette USFS Steve Negri Tetra Tech Jon Nelson High Desert Museum Volunteer Leslie Nelson TNC Kelli Neumann Volunteer Bill NewComb Volunteer Rock Climber Bruce Newhouse Volunteer

Appendix 1 8 Sarah Nichols WEST Melissa Nicolli USFWS Jerry Niehuser Volunteer Steve Niemela ODFW Daniele Nisewanger Volunteer Don Nisewanger Volunteer Eric Nolte WEST Lars Norgren Volunteer Lynn Norris Volunteer Sarah Norton Volunteer Mark Novak Volunteer Rebecca Novak Volunteer Larry Nurre Volunteer _group_ NWC Northwest Wildlife Consultants & Volunteer Sanders Nye Volunteer Sean O'Connor Volunteer Cliff Oakley Volunteer Matt Obradovich BLM Jane Olson Volunteer Charlotte Opp OEF Ralph Opp OEF _group_ OPRDIV OPRD Interpretive Volunteers Rob Osborn Volunteer Bill Osborne Volunteer Kim Owens Volunteer John Owens BLM Joel Pagel USFWS & Volunteer Andrew Passarelli USFS Katie Passarelli ODFW Paul Patton OPRD Ralph Paull Volunteer Michelle Pauly Volunteer Jon Paustian ODFW Bill Pearcy Volunteer Peter Pearsall Volunteer Larry Pecenka ODFW Mark Penninger USFS Olivia Perry BLM Ellen Peterson Volunteer Stacia Peterson Volunteer _group_ PGE Portland General Electric Biologists Robbie Piehl USFS Sheryl Pierce Volunteer LaRue Piersol Volunteer Robert Piersol Volunteer Tim Pitz NWC & Volunteer Eliana Pool BLM Stephanie Powers USFS Amy Price BLM Bill Price Volunteer Justin Primus ODFW David Probasco BLM Elizabeth Quinn Volunteer Fred Ramsey Volunteer Brian Ratliff ODFW Jamie Ratliff USFS Clark Reames USFS Erich Reeder BLM Larry Reigel USFWS Clare Reimers Volunteer Lisa Renan BLM & Volunteer

Appendix 1 9 Paul Rentz Volunteer Terry Reynolds USFS Kelly Rios Volunteer Jesse Ritter Volunteer Roger Robb Volunteer Connie Robbins Volunteer Perry Robbins Volunteer Anne Roberts USFS David Roberts Volunteer Diane Roberts Volunteer Thomas Robertson Silverhawk Aviation Mike Rochelle Weyerhaeuser Co. Tim Rodenkirk Volunteer Dave Roelofs BLM Trisha Roninger USFWS Robin Rose Volunteer Sara Rose Volunteer Andrew Rosenberg ODFW Junior Ruiz Volunteer Barb Rumer Volunteer Jelena Runjaic USFS C Runnels BLM Marissa Russell BLM M Rustand BLM Estephy Sabin BLM Jennifer Sanborn USFS Peter Sanzenbacher ABR Inc. & Volunteer Maggie Saslow Volunteer Randall Scarlett USFS Jake Schas Volunteer Carl Scheeler CTUIR Ken Scheffler USFWS Duane Schiedler Volunteer Julie Schiedler Volunteer Abbott Schindler Volunteer Mike Schlegel Tetra Tech Jay Schleier OPRD Ed Schmidt Volunteer Laingdon Schmidtt Volunteer Climber Karl Schneck Volunteer Julie Schneider Volunteer Ethan Schniedermeyer OSU Diane Schuder Volunteer Dick Schuder Volunteer Paige Scofield Volunteer Chris Scranton Volunteer Pam Scranton Volunteer Trent Seager Volunteer Steve Seibel Volunteer Ruby Seitz USFS Lynn Sharp Volunteer Sandy Sharp Volunteer Charlie Shaw Volunteer _group_ Sheldon Hart Mountain NWR USFWS Rachel Shelton Volunteer David Shepherdson Oregon Zoo Hud Sherlock Volunteer Jean Sherlock Volunteer Andrew Shields Roaring Springs Ranch Steve Shunk Volunteer Jeannine Sibley USFS

Appendix 1 10 Will Siegrist OPRD Interpretive Volunteer Angela Sitz USFWS Kendra Sloan BLM A'naka Smith Volunteer Allan Smith Dry Cr Landfill Colin Smith Volunteer Kei Smith Volunteer Kevin Smith Volunteer Mary Smith Volunteer Paul Smith USFS Roger Smith USFS Robin Snider BLM Dan Somers ODFW Rob Spaul Boise State University David Speten TKT (The Klamath Tribes) Anthony Spitzack USFS Dede Steele Volunteer & USFS retired Karen Steenhof USGS & Volunteer _group_ Sterling Sterling Rope Mark Stern Volunteer Mark Stevens Volunteer Denise Strejc BLM Nick Strnad Volunteer Crystal Strobl ODFW Matt Stuber USFWS Skyler Suhrer BLM Paul Sullivan Volunteer Dan Suther Volunteer Joan Suther Volunteer Susan Swank Volunteer Nancy Swearinger Volunteer Steve Swearinger Volunteer Erik Taylor BLM Leanna Taylor Volunteer Robert Taylor TNC Ray Temple Volunteer _group_ Tetra Tech Tetra Tech Biologists Liz Thill Volunteer Charlie Thomas Volunteer David Thompson Volunteer Houston Thompson BLM Shirley Thompson Volunteer Vernon Threlkeld Volunteer Oswald Tias CTWS Fiona Toland USFWS Volunteer Rebecca Toland USFWS Volunteer Scott Torland ODFW Bob Tucker Volunteer Carole Tucker Volunteer Bridget Tuerler USFWS Andy Tullis Bend Bulletin Natalie Turley Idaho Power Kelley Turner Hamer Environmental Tim Unterwegner Volunteer Tracie Unterwegner Volunteer _group_ USFWS Malheur National Wildlife Refuge _group_ USFWS Portland USFWS Jon VanDerZee EDP Renewables Dan Varland Volunteer Mary Verbeck Volunteer Rick Vetter Volunteer

Appendix 1 11 David Vick Volunteer Evan Vick Volunteer Sandra Vistine-Amdor Idaho Power Kay Voight Volunteer Elzi Volk USFWS Volunteer Dale Waddell Volunteer Waldo Wakefield Volunteer Patty Walcott USFS Barb Wales Volunteer John Walker USFS Michael Wallace HDR Inc. John Waller Volunteer Jim Walthers Volunteer Jerry Watkins Volunteer Barbara Webb USFS Faye Weekley USFWS Emily Weidner Volunteer Jennifer Weikel ODF Claire Weiser Volunteer ? Wells Ranch Manager Karin Wessman OPRD Interpretive Volunteer _group_ WEST, Inc. WEST, Inc. Biologists Ken Wheeler Volunteer Myra Whipple USFS Carl White TKT (The Klamath Tribes) Stephanie White BLM Suzy Whittey Volunteer Jane Whitticar Volunteer Mary Wilbur Diamond Valley Rancher Amanda Wilhelm High Desert Museum Volunteer Jake Willard Volunteer John Williams Volunteer Eric Williamson Volunteer Becky Willis-Zaremba Volunteer Frieda Willis-Zaremba Volunteer D Wills Volunteer S Wills Volunteer Elizabeth Willy USFWS Harv Wilson Volunteer Scott Wiltsey Volunteer Cole Winton ODFW Heather Wise BLM Jay Withgott Volunteer Walt Wolfe Raven Research & Volunteer Brian Woodbridge USFWS Lynn Woodward Volunteer Rob Worral Volunteer Angie Worthing BLM Simon Wray ODFW & Volunteer Matt Wyatt ODFW Brad Wymore Portland General Electric Kate Yates BLM Nancy Yialouris Volunteer ? Young USFS Melissa Yzquierdo BLM Cindy Zalunardo Volunteer Craig Zimprich Volunteer Janet Zuelke Volunteer

Appendix 1 12 Appendix 2. Codes (underlined) and definitions used to categorize annual results of monitoring (outcomes) at golden eagle nesting areas in Oregon, 2011–2018.

Codes not used in occupation or productivity calculations: zzz = Not discovered yet (starting with 2011). NS = NOT SURVEYED - No reports received on observations at the nesting area. UNXX = Survey(s) not during the nesting season (Jan-Aug) and no eagles or evidence of use. UNDX = POSSIBLY UNOCCUPIED - Survey not to USFWS protocol. No eagles observed at an historical nesting area, including areas with no known nest. OCXX = POSSIBLY OCCUPIED - Survey not to USFWS protocol. Eagle(s) and no nest, repaired nest and no eagles, or nest and non-adult eagle at an historical nesting area. x = a prefix added to the NS, UNXX, UNDX and OCXX outcome codes for nesting areas that don't meet the requirements for a nesting area currently.

Codes used in occupation calculations; not used in productivity calculations: OCCX = OCCUPIED - Breeding-age eagle(s) observed but number of eagles not reported; outcome unknown. OC1X = OCCUPIED 1 - 1 breeding-age eagle and a nest; outcome unknown. OC2X = OCCUPIED 2 - 2 breeding-age eagles and a nest; outcome unknown. OCUX = OCCUPIED, EVIDENCE OF USE - No young observed; outcome unknown. OCEX = OCCUPIED, EVIDENCE OF EGGS - Outcome unknown; also used for all sites where fresh eggs were collected.

Codes used in occupation and productivity calculations: UNOC = UNOCCUPIED - Nest present and USFWS protocol met; no breeding-age eagles detected. OCCF = OCCUPIED, FAILED - Breeding-age eagle(s) and a nest observed; no evidence of eggs. OC1F = OCCUPIED 1, FAILED - 1 breeding-age eagle and a nest observed; no evidence of eggs. OC2F = OCCUPIED 2, FAILED - 2 breeding-age eagles and a nest observed; no evidence of eggs. OCEF = OCCUPIED, EVIDENCE OF EGGS, FAILED - Evidence of eggs, but no live young ≥7w; includes dead chicks on or near the nest.

Codes used in occupation and productivity calculations: 1d = SUCCESSFUL, 1 YOUNG - Nestling less than 7 weeks old. 2d = SUCCESSFUL, 2 YOUNG - One or both nestlings less than 7 weeks old. 3d = SUCCESSFUL, 3 YOUNG - At least one nestling less than 7 weeks old. 1 = SUCCESSFUL, 1 YOUNG - Nestling or fledgling 7 weeks old or older. 2 = SUCCESSFUL, 2 YOUNG - Nestlings or fledglings 7 weeks old or older. 3 = SUCCESSFUL, 3 YOUNG - Nestlings or fledglings 7 weeks old or older. Appendix 3. Selected terms used to describe results of surveys of golden eagle nesting areas in Oregon, 2011–2018. Rejected terms highlighted with yellow and strikethrough used in previous literature shown for comparative purposes. Appendix 4. Early banding and telemetry results for 102 golden eagle nestlings from 68 nesting areas in Oregon, 2012–2014.

Breeding Area Band Sex PTT1 Post-Banding County Code Name Date Number (M or F) Number Welfare Note Latest Post-Fledging Encounter Note

DESC OR_GE_0278 Cougar Butte 5/15/12 0709-02302 Alive DESC OR_GE_0280 Twin Pines 5/15/12 0709-02301 Alive LAKE OR_GE_0264 Oatman Flat (1) 5/16/12 0709-02303 1 Alive, 1 Not Located LAKE OR_GE_0264 Oatman Flat (2) 5/16/12 0709-02304 (see preceding note) LAKE OR_GE_1155 Connley Hills (1) 5/16/12 0709-02305 Alive LAKE OR_GE_1155 Connley Hills (2) 5/16/12 0709-02306 Alive DESC OR_GE_0319 Jaguar Road 5/22/12 0629-15699 Alive Eaglet weak when banded then fledged. DESC OR_GE_0333 Deep Canyon (1) 5/22/12 0709-02307 1 Alive, 1 Not Located DESC OR_GE_0333 Deep Canyon (2) 5/22/12 0709-02308 (see preceding note)

HARN OR_GE_0127 Buchanan 5/15/13 0799-00216 Not Determined HARN OR_GE_0526 Crane Butte (1) 5/16/13 0799-00217 Not Determined Electrocuted nearby Mar 2014. HARN OR_GE_0526 Crane Butte (2) 5/16/13 0709-02292 Not Determined HARN OR_GE_1271 House Butte (1) 5/17/13 0709-02293 Not Determined HARN OR_GE_1271 House Butte (2) 5/17/13 0709-02294 Not Determined HARN OR_GE_0521 Wrights Point (1) 5/19/13 0799-00218 Not Determined HARN OR_GE_0521 Wrights Point (2) 5/19/13 0709-02295 Not Determined HARN OR_GE_0545 Swamp Cr 5/20/13 0709-02296 Not Determined HARN OR_GE_0552 Jackass Mountain (1) 5/21/13 0799-00224 Not Determined HARN OR_GE_0552 Jackass Mountain (2) 5/21/13 0709-02299 Not Determined HARN OR_GE_0505 Moon Res Outlet 5/22/13 0709-02300 Not Determined HARN OR_GE_1184 Malheur R 5/23/13 0709-02309 Not Determined HARN OR_GE_0568 Catlow Valley (1) 5/24/13 0709-02311 1 Dead, 1 Not Located HARN OR_GE_0568 Catlow Valley (2) 5/24/13 0709-02312 Not Determined HARN OR_GE_0199 Drewsey 5/25/13 0709-02320 Not Determined Captured and released near Prescott AZ, Dec 2013. HARN OR_GE_0557 Baca L Radio Tower (1) 5/30/13 0709-02297 Not Determined HARN OR_GE_0557 Baca L Radio Tower (2) 5/30/13 0709-02298 Not Determined

JEFF OR_GE_0230 Willow Cr Powerline (1) 4/26/14 0709-01687 Alive JEFF OR_GE_0230 Willow Cr Powerline (2) 4/26/14 0709-01688 Alive HARN OR_GE_0443 Big Stick Canyon (1) 5/3/14 0709-04166 F 121723 Alive & Fledged Transmitter likely shed and recovered near Wagontire, OR; no evidence of bird remains, Sep. 2014. HARN OR_GE_0443 Big Stick Canyon (2) 5/3/14 0709-04167 M 121721 Alive & Fledged Bird died or transmitter shed and unrecovered; no evidence of bird remains, Aug. 2014.

HARN OR_GE_1189 Big Stick Well 5/4/14 0709-04168 M 136658 Alive & Fledged Transmitter shed and recovered below nest, adults and juvenile present, Aug. 2014.

HARN OR_GE_0442 Tank Cr (1) 5/6/14 0709-04169 Not located HARN OR_GE_0442 Tank Cr (2) 5/6/14 0709-04170 M 136657 Alive & Fledged Bird wintered east of Redding, CA, Feb. 2015. HARN OR_GE_0442 Tank Cr (3) 5/6/14 0709-04171 F 129719 Alive & Fledged Bird died or transmitter shed near nest; no evidence of bird remains, Aug. 2014.

LAKE2 OR_GE_0115 Doughnut Mountain (1) 5/7/14 0709-02011 Alive LAKE2 OR_GE_0115 Doughnut Mountain (2) 5/7/14 0709-02012 Alive LAKE2 OR_GE_1104 Klippel Point (1) 5/7/14 Not Banded Not Determined LAKE2 OR_GE_1104 Klippel Point (2) 5/7/14 Not Banded Not Determined HARN OR_GE_1190 Alec Butte (1) 5/7/14 0709-04172 F 136655 Alive & Fledged Bird wintering in Christmas Valley, OR, Feb 2015 HARN OR_GE_1190 Alec Butte (2) 5/7/14 0709-04173 M 136656 Alive & Fledged Bird died but unknown cause, transmitter recovered near Wagontire, OR, Dec. 2014.

LAKE2 OR_GE_1193 Poverty Basin (1) 5/7/14 0709-02013 Alive LAKE2 OR_GE_1193 Poverty Basin (2) 5/7/14 0709-02014 Alive HARN OR_GE_0536 Buena Buttes (1) 5/8/14 0799-00711 Alive HARN OR_GE_0536 Buena Buttes (2) 5/8/14 0709-04175 Alive LAKE2 OR_GE_0271 Cougar Mountain 5/9/14 0709-02016 Not Determined HARN OR_GE_0529 Virginia Valley 5/9/14 0709-01689 Alive LAKE2 OR_GE_1155 Connley Hills 5/9/14 0709-02015 Alive HARN OR_GE_0521 Wrights Point 5/10/14 0709-02268 Not located LAKE2 OR_GE_1001 Flat Iron Point (1) 5/11/14 Not Banded Not Determined LAKE2 OR_GE_1001 Flat Iron Point (2) 5/11/14 Not Banded Not Determined HARN OR_GE_0212 Bathtub Spring 5/12/14 0799-00712 F 136661 Alive & Fledged Transmitter likely shed, unrecovered, juvenile and adults present near nest, Jun 2014.

HARN OR_GE_0518 Coyote Point 5/12/14 0709-02270 Alive MALH OR_GE_1342 Visher Cr (1) 5/12/14 0719-01019 Alive MALH OR_GE_1342 Visher Cr (2) 5/12/14 0709-02269 Alive HARN OR_GE_0116 Table Butte 5/13/14 0799-00713 Alive HARN OR_GE_0511 Double O Flat 5/13/14 0709-04174 Alive HARN OR_GE_0554 Krumbo Res 5/13/14 0709-02271 Alive DESC2 OR_GE_0278 Cougar Butte (1) 5/14/14 0709-02017 Jumped, not found DESC2 OR_GE_0278 Cougar Butte (2) 5/14/14 0709-02018 Not Determined HARN OR_GE_1149 Anderson Butte 5/14/14 0709-02274 Alive

Appendix 4 1 HARN OR_GE_1361 Princeton South (1) 5/14/14 0709-02272 Alive HARN OR_GE_1361 Princeton South (2) 5/14/14 0709-02273 Alive HARN OR_GE_0545 Swamp Cr 5/15/14 0709-02275 M 136659 Alive & Fledged Bird last recorded near Diamond, OR, transmitter not functioning properly, Jan. 2015.

CROO2 OR_GE_1256 Rodman Rim (1) 5/15/14 0709-02019 Alive CROO2 OR_GE_1256 Rodman Rim (2) 5/15/14 0709-02020 Alive HARN OR_GE_0586 Coyote Gap South 5/17/14 0799-00714 Alive HARN OR_GE_0512 Hughet Spring 5/18/14 0709-02278 F 136660 Alive & Fledged Transmitter likely shed and recovered, no evidence of bird remains; east of Salt Lake City, UT, Jan. 2015.

HARN OR_GE_0537 Oliver Spring 5/22/14 0709-04176 Alive DESC2 OR_GE_0083 Bull Flat (1) 5/23/14 0709-02021 Died (tested positive for brodifacoum) DESC2 OR_GE_0083 Bull Flat (2) 5/23/14 0709-02022 Died3 HARN OR_GE_0127 Buchanan (1) 5/23/14 0799-00152 F Alive HARN OR_GE_0127 Buchanan (2) 5/23/14 0799-00153 F Alive HARN OR_GE_0199 Drewsey 5/23/14 0709-02276 Alive HARN OR_GE_1184 Malheur R (1) 5/23/14 0709-02277 Alive HARN OR_GE_1184 Malheur R (2) 5/23/14 0709-04177 Alive HARN OR_GE_1271 House Butte (1) 5/23/14 0709-01690 F Not located HARN OR_GE_1271 House Butte (2) 5/23/14 0709-01691 M Not located LAKE2 OR_GE_0269 Gerkin Rim (1) 5/24/14 0709-02025 Alive LAKE2 OR_GE_0269 Gerkin Rim (2) 5/24/14 0709-02026 Alive MALH OR_GE_0501 South Fork Malheur R 5/24/14 0709-04178 Alive LAKE2 OR_GE_0660 Buck Cr Canyon Silver L (1) 5/24/14 0709-02023 Alive LAKE2 OR_GE_0660 Buck Cr Canyon Silver L (2) 5/24/14 0709-02024 Alive LAKE2 OR_GE_0268 Black Hills 5/26/14 0709-02310 Alive LAKE2 OR_GE_0440 Alkali Flat Chewaucan R 5/27/14 0709-04191 Not Determined LAKE2 OR_GE_1109 Burma Rim 5/27/14 0709-04192 Alive DESC2 OR_GE_0327 Rim Rock Ranch 5/28/14 0709-02028 Alive DESC2 OR_GE_0330 Odin Falls Lower Bridge 5/28/14 0709-02027 Alive HARN OR_GE_0540 Buena Vista North 5/29/14 0709-04179 Alive CROO2 OR_GE_1257 Norman Canyon Mouth (1) 5/29/14 0709-02029 Alive CROO2 OR_GE_1257 Norman Canyon Mouth (2) 5/29/14 0709-02030 Alive LAKE2 OR_GE_0262 Silver Cr (1) 5/30/14 0709-02314 Alive LAKE2 OR_GE_0262 Silver Cr (2) 5/30/14 0709-02315 Died (apparent siblicide) HARN OR_GE_0542 Diamond Valley (1) 5/30/14 0709-04180 Alive HARN OR_GE_0542 Diamond Valley (2) 5/30/14 0799-00715 Alive LAKE2 OR_GE_1158 Chewaucan R (Mill Cr) 5/30/14 0709-02313 Alive HARN OR_GE_0453 Kiger Cr 6/1/14 0709-04181 Alive HARN OR_GE_0030 Buzzard Cr (1) 6/5/14 0709-04151 Alive HARN OR_GE_0030 Buzzard Cr (2) 6/5/14 0709-04152 Alive LAKE2 OR_GE_0342 Hogback Summit (1) 6/5/14 0709-02034 Alive LAKE2 OR_GE_0342 Hogback Summit (2) 6/5/14 0709-02033 Alive LAKE2 OR_GE_1337 Diablo Mountain Banta Well (1) 6/5/14 0709-02031 Not Determined LAKE2 OR_GE_1337 Diablo Mountain Banta Well (2) 6/5/14 0709-02032 Not Determined LAKE2 OR_GE_0264 Oatman Flat 6/6/14 0709-02037 Alive LAKE2 OR_GE_1054 Moss Creek (1) 6/6/14 0709-02035 Alive LAKE2 OR_GE_1054 Moss Creek (2) 6/6/14 0709-02036 Alive LAKE2 OR_GE_1272 Monument Rock Slide Mountain 6/12/14 0709-02051 Not Determined

1 PTT = Platform Telemetry Transmitter (satellite transmitter). 2 Data provided by USFWS (David Leal, USFWS, Portland OR personal communication). 3 Nestling found dead in the nest; tissues too degraded for necropsy; possible exposure to anticoagulant rodenticide, brodifacoum, like its sibling.

Appendix 4 2 Appendix 5. Report on Oregon golden eagle band returns. Leal, D. A. 2016. Oregon golden eagle band returns (1955 to 2013). U.S. Fish and Wildlife Service, Portland, Oregon, USA.

Oregon Golden Eagle band returns (1955 to 2013)

From 1955 through 2013, 340 wild golden eagles (Aquila chrysaetos) were banded in Oregon with U.S. Fish and Wildlife Service (USFWS) or U.S. Geological Survey (USGS) metal leg bands. Birds were banded at various ages (Table 1) with the vast majority banded as “local” or nestlings (n=270, 79.4%) (Table 1). In a small percentage of cases other forms of auxiliary markers were attached, such as patagial wing tags, colored leg bands or radio telemetry transmitters. In 2014 and 2015, approximately 80 and 28 nestlings, respectively, were banded during a USFWS and USGS study to quantify lead exposure in golden eagle nestlings. These birds were banded in Deschutes, Crook, Lake, Harney and Malheur Counties in cooperation with currently-permitted banders. This recent banding effort represents the most bands deployed in a given 1- or 2-year period; however, limited encounters (bird recaptured or found dead or injured) with these bands preclude data analysis or interpretation. Therefore, the focus of this review will be on the 340 bands deployed prior to 2014.

The information on golden eagles banded in Oregon and encountered within and outside of Oregon was provided by the USGS Bird Banding Laboratory (BBL), Laurel, Maryland. Because of the difficulty in reading band numbers on free-flying eagles, the vast majority of encounters are of bands returned from dead or injured birds. Of the 340 wild golden eagles banded in Oregon prior to 2014, 35 (10.3 %) have been encountered. Isaacs and Anthony (2011) reported an encounter rate of 14% for bald eagles (Haliaeetus leucocephalus) banded in Oregon. Of the 34 birds encountered with sufficient locational data, 26 were in Oregon (76.5%), three were in California (8.8%), and there was one each (2.9%) from Nevada, Washington, Arizona, Saskatchewan, Canada, and Baja Del Norte, Mexico. Twenty-seven (77.1%) of the 35 encountered eagles were banded as nestlings three were “hatch year” birds, one was a “second year” bird, one an “after second year” bird, and three were identified as “after third year” birds (see Table 1 for definitions of year classes). Four birds (12.5%) were encountered alive and two were recaptured to deploy new radio transmitters. Three birds (11%) had incomplete encounter data preventing their use in age or distance analyses or both.

Eagles banded in several other States also have been encountered in Oregon, including five from California, four from Idaho, three from Washington and one each from Montana and Nevada. These birds are not included in the analyses but are simply reported to illustrate movement based on band encounters. While band returns may suggest one-way movement from Idaho to Oregon this is likely a product of low sample size because recent telemetry data from juvenile birds banded in Oregon in 2014 has shown movement from Oregon to Idaho, Wyoming, and Utah, which is not reflected in band encounters. Additionally of interest is the absence of Alaskan birds encountered in Oregon since telemetry data indicates (Steve B. Lewis, biologist USFWS, pers comm. 2015) that individuals from migratory populations, such as from Alaska, overwinter in Oregon or pass through on migration.

Band Returns and Age

Encounter information from all golden eagles banded in Oregon allowed for calculating an age at death for all eagles banded as nestlings, hatch year or second year birds, as well as calculating an encounter distance from the banding site. As noted previously, in the majority of cases bands were attached to a nestling, which provides the maximum information on dispersal distance from the natal area. Telemetry data on juvenile golden eagles equipped with satellite transmitters in Oregon in 2014 has shown that by late August birds are conducting long flights away from their natal areas; therefore, birds banded that are already flying by mid to late August are considered of unknown origin.

For the purposes of calculating an average and maximum age for golden eagles where hatch year was known (n=24), April 1 was used as a standardized hatch date based on the nesting chronology for golden eagles in Oregon (Isaacs 2015). The age for golden eagles of known hatch year that were dead upon encounter (n=24) ranged from 135 to 8,646 days (4.5 months to 23 years, 8.4 months) with a mean age of 1,446 days (approximately 4 years). These calculations did not include “after third year” and “after second year” birds due to uncertainty of the actual hatch year. While no encountered birds in the BBL records (prior to 2014) died before fledging, six (27 %) died within their first year and 14 (58 %) total died within 2 years of hatching. Eight (33%) of the known age eagles lived longer than 4 years and four (18%) lived longer than 8 years (Figure 1). Four individuals were encountered alive and therefore are not used in age calculations; however, of those birds, one each was encountered in its first, second, sixth and tenth year.

Band Returns and Natal Dispersal

In addition to providing information on age, encounters of banded birds may also inform our knowledge of dispersal, particularly when banded as a nestling and surviving to adulthood. Golden eagles banded in Oregon dispersed in a variety of directions and distances based on encounters, but did not disperse west across the Cascade Range, suggesting that eagles primarily disperse through preferred open habitat and not in a truly random direction (Figure 2).

We attempted to follow Millsap et al. (2014) to determine natal dispersal distance; however, we could not be as restrictive with the data due to the small number of useable encounters. Dispersal distance was calculated using GIS (ArcMap 10.3.1) and is a straight-line measurement between banding location and encounter location. To inform natal dispersal distance, we used encounters of eagles banded as nestlings and encountered as adults when at least 4.75 years old (n=7). The 4.75-year-old age threshold is a conservative estimate of the age at first breeding based on other studies showing golden eagles were rarely (<3%) established in breeding pairs as subadults (Steenhoff et al.1983) and the earliest they would attain full adult plumage is at 4 years of age (Steenhoff et al.1984). There were seven encounters that met these basic criteria with one additional encounter just below the threshold at 4.5 years of age. Data were analyzed with and without this additional encounter and the results changed little; however, for the purposes of reporting natal dispersal distance we did not include the 4.5-year-old bird. Dispersal distance ranged from 7 to 986 miles (11.3 to 1,586 km) with a mean distance of approximately 161 miles (259 km) and a median distance of 24.5 miles (39.4 km). While the sample size is small for Oregon alone, the median natal dispersal distance of 39.4 km is 7 km less than reported by Millsap et al. (2014) across the contiguous western U.S. Ages of the birds used in the Oregon natal dispersal distance analysis ranged from 5 years to 23 years and these birds were assumed to have been encountered in their breeding territory. Mean dispersal distance for all banded nestlings encountered dead or alive (n=26) was 155.4 miles (250 km). Of the eight birds that dispersed greater than 100 miles (160.9 km) upon encounter (dead or alive), seven were juveniles or subadults less than 4.75 years old and one was an adult greater than 4.75 years old.

Acknowledgements: Special thanks to Rick Gerhardt and Jim and Sue Anderson for reviewing the draft and checking the BBL, as well as reviewing their records to complete the Oregon encounter data.

Literature Cited

Isaacs, F.B. 2015. Golden eagles (Aquila chrysaetos) nesting in Oregon, 2011-2014: Final report, 10 February 2015. Oregon Eagle Foundation, Inc., Klamath Falls, Oregon. 31pp + appendices.

Isaacs, F.B. and R.G. Anthony. 2011. Bald eagles (Haliaeetus leucocephalus) nesting in Oregon and along the Lower Columbia River, 1978-2007: Final report. Oregon Cooperative Fish and Wildlife Research Unit, Department of Fisheries and Wildlife, Oregon State University, Corvallis. 242p.

Millsap, B.A., A.R. Harmata, D.W. Stalecker, and D.G. Mikesic. 2014. Natal dispersal of bald and golden eagles originating in the coterminous United States as inferred from band encounters. Journal of Raptor Research. 48(1):13-23.

Steenhof, K., M.N. Kochert, and J.H. Doremus. 1983. Nesting of subadult golden eagles in southwestern Idaho. Auk. 100:743-747.

Steenhof, K., M.N. Kochert, and M.Q. Moritsch. 1984. Dispersal and migration of southwestern Idaho raptors. Journal of Field Ornithology. 55:357-368.

Lewis, Steve B. 2015. Communication regarding individual golden eagles radio transmittered in Alaska wintering in Oregon in 2014 and 2015.

Table 1. USGS Bird Banding Lab Age (Year Class) Codes and number of wild golden eagles banded for each age, Oregon, 1955-2013.

Numeric Alpha Alpha Number in Description Code Code Translation Oregon A bird that cannot be placed in any of the classes below. Except in cases where data were not recorded or have been 0 U Unknown lost during the nesting season, ONLY BIRDS BANDED 0 AFTER THE BREEDING SEASON AND BEFORE JANUARY 1 CAN BE CORRECTLY CODED “U.” A bird known to have hatched before the calendar year of banding; year of hatch otherwise unknown. Example: After Hatching 1 AHY Banded 1997 - Hatched before January 1, 1997. Birds that 1 Year would have been coded “U” on December 31 “graduate” to class “AHY” on January 1. A bird capable of sustained flight and known to have 2 HY Hatching Year hatched during the calendar year in which it was banded. 39 Example: Banded 1997 - Hatched 1997. Nestling or recent fledgling; unable to determine which new 3 J Juvenile 0 code to use. A young bird incapable of sustained flight. After a young 4 L Local bird achieves sustained flight it becomes an “HY” until 270 December 31. A bird known to have hatched in the calendar year 5 SY Second Year preceding the year of banding and in its second calendar 9 year of life. Example: Banded 1997 - Hatched 1996. A bird known to have hatched earlier than the calendar year After Second preceding the year of banding; year of hatch otherwise 6 ASY 4 Year unknown. Example: Banded 1997 - Hatched 1995 or earlier. A bird known to have hatched in the calendar year 2 years 7 TY Third Year prior to the year of banding, now in its third calendar year of 1 life. Example: Banded 1997 - Hatched 1995. Numeric Alpha Alpha Number in Description Code Code Translation Oregon A bird known to have hatched prior to 2 years prior to the After Third 8 ATY year of banding, now in at least its fourth calendar year of 16 Year life. Example: Banded 1997 - Hatched 1994 or earlier. Total 340

9 8 7 6 Encounter by

of Eagles 5 age 1955 to 4 2013 3 Number 2 1 0 0-1 1-2 2-3 3-4 4-5 >5 Age in Years

Figure 1. Number and age (years) of golden eagles banded in Oregon and encountered dead. The bar denoted as “>5” represents adult birds with ages ranging from 5 to 23 years.

Figure 2. Dispersal of golden eagles banded in Oregon 1955 through 2013.