Monitoring Occupancy of Nesting Territories and Reproductive Success of

Golden Eagles and Gyrfalcons in Denali National Park and Preserve, Alaska

2005 Progress Report

Central Alaska Network, Vital Signs Monitoring Program

Adult Golden Eagle feeding two one-week old nestlings. Photograph by Michael W. Collopy.

Carol McIntyre,

Denali National Park and Preserve,

201 1st Ave., Fairbanks, AK 99701

EXECUTIVE SUMMARY

I monitored nesting territory occupancy and reproductive success of Golden Eagles (Aquila chrysaetos) and Gyrfalcons (Falco rusticolus) using data collected during two aerial surveys in Denali National Park and Preserve (Denali) in 2005. I also visited a sample of occupied Golden Eagle nesting territories to collect shed feathers for an ongoing genetics study and addled eggs for an ongoing contaminants monitoring study. The Golden Eagle nesting territory occupancy rate (87%) was similar to other years, but laying rate (61%), success rate (71%), and fledglings production (n = 40) were the highest since 2000 and 2001. The Gyrfalcon nesting territory occupancy rate (31%) was lower than most years, but success rate (75%) was higher than most years. Daily counts of snowshoe hare (Lepus americanus) and Willow Ptarmigan (Lagopus lagopus) indicated that their abundance is increasing and heading toward the peak of their 8-11 year cycle.

The continued stability of the territorial population of Golden Eagles and the apparent lack of subadults in the territorial population in Denali indicates either high survival of territorial eagles or an ample supply of non-territorial adult Golden Eagles (or floaters) exists to fill voids left by birds that die. We do not know survival or turnover rates of the territorial population; therefore, I cannot the model population dynamics of the territorial population of Golden Eagles in Denali. I expect that we will be able to identify individual Golden Eagles using DNA extracted from shed feathers. By collecting shed feathers at nesting territories among years, we will be able to determine turnover rates at nesting territories and perhaps survival rates of the territorial population.

INTRODUCTION

Golden Eagles and Gyrfalcons are large, diurnal raptors that nest in relatively high densities in the northeastern region of Denali (Swem et al. 1994, Kochert et al. 2002). In 1988, the National Park Service initiated a long-term program to monitor occupancy of nesting territories and reproductive success of Golden Eagles in Denali (McIntyre and Adams 1999). In 2004, the Central Alaska Monitoring Network (CAKN) selected Fauna Distribution and Abundance as one of its top three Vital Signs (along with Climate/Weather, and Vegetation Structure and Function) (MacCluskie and Oakley 2005). The Fauna Distribution and Abundance Vital Sign comprises monitoring efforts for a suite of vertebrate species including Golden Eagles in Denali, Bald Eagles (Haliaeetus leucocephalus) in Wrangell-St. Elias National Park and Preserve, and Peregrine Falcons (Falco peregrinus) in Yukon-Charley Rivers National Preserve.

Golden Eagles are top-trophic level predators and they respond quickly to changes in their environment by changing their breeding activities. Because of our long-term monitoring efforts, we know that Denali contains the highest reported density of nesting Golden Eagles in North America (Kochert et al. 2002). Further, the long-term studies in Denali (1987 to present) provide the only contemporary information on the reproductive characteristics of a large migratory population of Golden Eagles in northern North America. This monitoring program and the various research projects originating from this program have provided substantial contributions to the understanding of Golden Eagle ecology in North America, particularly for northern breeding migratory populations (McIntyre and Adams 1999, Kochert and Steenhof 2002, Kochert et al. 2002, McIntyre 2002, McIntyre and Collopy 2006, McIntyre et al. 2006 a,b). Data collected in Denali is directly comparable to the only other long-term data set for this species in North America, collected in the Snake River Birds of Prey National Conservation Area. Continuous and comparable data from these areas provide valuable insights about eagle responses to different environmental conditions across diverse geographical areas (Kochert and Steenhof 2002). This project also provides park managers with contemporary information on location and status of nesting territories and nest sites in Denali.

Although Gyrfalcons are not a component of the CAKN Vital Signs Monitoring program, we continue to collect data on their nesting territory occupancy and reproductive success concurrently with the Golden Eagle monitoring program. Gyrfalcons and Golden Eagles nest in similar habitat, and Gyrfalcons often use Golden Eagle nest structures for their own nesting attempts. Since 1988, we have assembled a unique long-term data set on the nesting ecology of these two large, long-lived sympatric nesting raptors. The US Fish and Wildlife Service (FWS) recently began studying Gyrfalcon ecology in southwestern Alaska as part of their efforts to develop a statewide monitoring program for this species. Gyrfalcons are a priority species for the FWS because Alaska supports the only breeding population of this species in the United States. Our historic results and experiences studying nesting Gyrfalcons in Denali will be valuable for developing the new statewide long-term monitoring program for this species which will be implemented by 2010 (P. Schempf, U.S. Fish and Wildlife Service, personal communication).

This report summarizes results of our monitoring activities for Golden Eagles and Gyrfalcons in Denali in 2005, highlights some of our achievements in 2005, and provides an outline of activities planned for 2006.

STUDY AREA

The long-term survey area is in the northern foothills of the Alaska Range in northeastern Denali in central Alaska (63º 36’N, 149º 39’W). The area contains one of the highest reported densities of nesting Golden Eagles (Kochert et al. 2002) and a relatively high density of nesting Gyrfalcons (Swem et al. 1994). The survey area is bounded on the east by the Nenana River, on the south by the crest of the Alaska Range, on the west by the Muldrow Glacier and Boundary Creek, and on the north by the north slope of the foothills of the Alaska Range (also known as the Outer Range) (Figure 1). Rugged, mountainous terrain interspersed by broad glacial valleys and upland areas characterize the 2,100 km2 survey area. Elevations range from 427 m in the lowlands and river bottoms to 1,372 m along the foothill summits.

METHODS

Terminology

I used standardized terminology to describe nesting territory occupancy and reproductive success (Appendix A), standardized calculations to generate metrics of reproductive success (Appendix B), and standardized techniques for monitoring nesting territory occupancy and reproductive success. All terminology, methodologies and processes to determine occupancy and reproductive success (Figure 2) follow recommendation made by Steenhof (1987). Although Steenhof (1987) suggests that studies should focus measurements of productivity based on the territorial population, many studies do not include this measurement. Therefore, I construct three measurements of productivity to compare our results with other Golden Eagles studies in North America: 1) fledglings per territorial pair, 2) fledglings per laying pair, and 3) fledglings per successful pair.

Aerial Surveys

I used two aerial surveys to determine nesting territory occupancy and reproductive success of Golden Eagles and Gyrfalcons in Denali in 2005. I conducted the first aerial survey (the occupancy and activity survey) after most clutches were completed but before most nest failures occurred. The objective of the occupancy and activity survey is to document occupancy and breeding activity at nesting territories. I conducted the second aerial survey (the productivity survey) after most nestlings reached 80% of their age at fledging, but before they left the nest (fledged). The objective of the productivity survey is to count the number of nestlings and fledglings, and to document reproductive success.

Occupancy and Activity Survey. A week before the survey I reviewed the database and prepared a comprehensive map (1:250,000 topographic map) of the survey area including the locations of all known Golden Eagle and Gyrfalcon nest site in the study area. I recorded my observations on this map during the surveys and used the map as a navigation aid.

I conducted the occupancy and activity survey on three consecutive days between 26 April and 28April 2005 from a Robinson R-44 helicopter (Quicksilver Air, Fairbanks, Alaska). Surveys started at approximately 7:30 am and ended at approximately 6:30 pm. During the occupancy and activity survey, I attempted to observe the contents of all known nest sites within all known nesting territories in the study area. I used 10x 40 binoculars during all aerial surveys.

As we approached each known nesting territory, I instructed the pilot to slow down and provided him with details on the location of each nest site. We slowly approached each nest site from directly it front of it providing the incubating eagle with a clear view of the approaching helicopter. The pilot generally oriented the helicopter about 100 meters in front of the nest cliff and about 100 meters above the nest, and I looked directly out my window into each nest to observe its contents. During nest observations, the pilot flew the helicopter as slow as possible and often hovered. As soon as I detected evidence of occupation, (an incubating bird, eggs, or nest building), I recorded my observations on the survey map and we continued on to the next territory. In some cases, I detected an incubating eagle before we approached within 300 meters of the nest. In these circumstances, I quickly recorded my observations and instructed the pilot to fly to the next nesting territory.

At each nesting territory, I recorded the number of passes required to determine occupancy. I also recorded the response of incubating Golden Eagles to the helicopter as flush (eagles that left the nest when we approached) or no flush (eagles that continued incubation during our observations).

If I could not determine the occupancy status of all known nest sites within a nesting territory from the helicopter, I returned to the area later that day after I completed making aerial observations at other nesting territories. I used this strategy to take advantage of good survey weather before turbulence built up in the afternoon. During the return visits, I instructed the pilot to fly slowly along nearby mountainsides as I searched cliffs and rock outcroppings for previously undiscovered or new nest sites. If could not determine occupancy from the air during the return visit, I instructed the pilot to land at a nearby vantage point and made observations from the ground. If I could not determine occupancy after two hours of ground observations, I defined the territory as “occupancy unknown” and I revisited the area later in the nesting season to determine occupancy (see nest visits below).

During the occupancy and activity survey, I searched for new or previously undocumented nest sites and recorded their location using the on-board Global Positioning System (GPS) and my survey map. I also classified all Golden Eagles observed during the survey as adults or subadults based on their plumage.

I was the primary observer during the occupancy and activity survey. Nikki Demers (NPS) assisted with the survey the afternoon of 27 April 2006 and Jane Bryant (NPS) assisted with the survey on 28 April 2006.

Productivity survey. I conducted the productivity survey on 8 July 2006 from a Robinson R-44 helicopter (Quicksilver Air, Fairbanks, Alaska). Several days before the survey, I reviewed the survey map that I used during the occupancy and activity survey. I recorded my observations on this map and used the map as a navigation aid during the survey.

At each occupied nest, I counted the number of nestlings and estimated their age based on their feather development. I also recorded the presence and number of addled (unhatched) eggs. I used 10x 40 binoculars during all aerial surveys. I was the primary observer during the productivity survey and Ryan Drum (NPS) assisted me with the survey. During the productivity survey, I searched for new or previously undocumented nest sites and recorded their location using the on-board Global Positioning System (GPS) and my survey map. I also classified all free-flying Golden Eagles (not fledglings) observed during the productivity survey as adults or subadults based on their plumage.

Ground-based observations

I monitored occupied Golden Eagle and Gyrfalcons nests that were located within view of the Denali park road throughout the nesting season to calibrate my estimates of nesting phenology. I used 10 x 40 binoculars and a 20-60x power spotting scope during these observations. During ground-based observations, I searched for new or previously undocumented nest sites and recorded their location using the on-board Global Positioning System (GPS) and my survey map. I also classified all free-flying Golden Eagles observed during ground observations as adult or subadult based on their plumage.

Visiting Golden Eagle nesting territories

As part of a collaborative project with Sandy Talbot, Molecular Genetics Lab, U.S. Geological Survey (USGS), Alaska Science Center, I am collecting shed feathers at a sample of nest sites to determine if we can accurately identify individual eagles in territories over time by using DNA extracted from the feathers. In 2005, I visited 12 Golden Eagle nesting territories to collect shed feathers. I used a Robinson R-44 helicopter (Quicksilver Air, Fairbanks, Alaska) to gain access to remote nesting territories from 5 to 8 July 2006, and foot travel to gain access to nesting territories that were <5km of the Denali park road from 12 to 15 July 2006. Ryan Drum and Sally Andersen, NPS seasonal biological technicians, assisted me with nest site visits. During nest visits and travel associated with these visits, I searched for new or previously undocumented nest sites and recorded their location using the on-board Global Positioning System (GPS) and my survey map. I also classified all free-flying Golden Eagles observed during nest visits as adult or subadult based on their plumage characteristics.

During nest site visits, we collected shed adult Golden Eagle feathers beneath occupied nests, and near perches and roost sites. We placed each feather in a paper envelop and labeled the envelope with the name of the nesting territory and date. All feathers were collected under U.S. Fish and Wildlife Service (FWS) Migratory Bird Banding Permit 22035 (Carol McIntyre, master permitee), FWS Eagle Scientific Permit (MB 043645-0) and a State of Alaska, Department of Fish and Game, Scientific Permit (05-028). At the end of the summer, I transferred the feather collection to Sandy Talbot, Molecular Genetics Lab, USGS Alaska Science Center, 1011 E. Tudor Road, Anchorage, Alaska. After extracting the DNA, Dr. Talbot (USGS) will transfer the feathers to Dr. Angela Matz, avian toxicologist, USFWS, Fairbanks, Alaska for contaminant analysis. After completing her sampling, Dr. Matz will transfer the feathers to the FWS Eagle Depository in Colorado.

I also collected addled eggs using the USFWS standardized protocol to document the presence of heavy metals including mercury as part of a collaborative project with Dr. Angela Matz. I collected one addled egg in 2005.

Counting snowshoe hare and Willow Ptarmigan.

I recorded numbers of adult snowshoe hare and adult Willow Ptarmigan that I saw during routine fieldwork from 15 April through 30 June 2005 and used number of individuals observed per field day per year as an index of their abundance (McIntyre and Adams 1999). I calculated this index to examine correlations between Golden Eagles and Gyrfalcons laying rates and broad-scale changes in their primary spring prey resources, snowshoe hare and Willow Ptarmigan (McIntyre and Adams 1999).

Other Observations.

I recorded all birds that I observed during all fieldwork. During the occupancy and activity survey, I recorded locations of grizzly bears (Ursus arctos), locations and numbers of Dall sheep lambs (Ovis dalli dalli), and burrows of arctic grounds squirrel (Spermophilus paryii).

RESULTS AND DISCUSSION

Survey effort

From 1988 to 2005, I monitored from 56 to 82 (Figure 3) Golden Eagle nesting territories annually; I monitored 77 nesting territories in 2005. I could not observe five historic nesting territories near the western end of the study area during the occupancy and activity survey because of extreme turbulence conditions. From 1988 to 2005, I monitored from 13 to 18 Gyrfalcon nesting territories annually (Figure 3); I monitored 13 Gyrfalcon nesting territories in 2005 (Figure 3). While there are not sufficient funds available through CAKN to observe all Gyrfalcon nesting territories in the area, we will continue to monitor as many nesting territories as possible with the current level of funding. Even with smaller sample sizes, we will continue to provide important information on Gyrfalcon reproduction in Denali.

Weather conditions during the first two days of the occupancy and activity surveys were favorable for surveys and observations, with light winds, warm temperatures, and cloudless skies. Weather conditions on the 3rd day of the occupancy and activity survey were poor, with winds >30 mph and extreme turbulence. Thunderstorms, rain and wind during the early part of the nest visits prevented us from visiting occupied nests, and confined our feather searches to areas below nests, and at perches and roosts. A break in the weather on 8 July 2005 (light winds, little turbulence, and good lighting) allowed me to observe the contents of all occupied nests in the study area.

I conducted the occupancy and activity survey during the same period as the last 17 years. Due to problems scheduling a helicopter in late July and early August for the productivity survey, I used counts of nestlings made on 8 July 2005 to estimate productivity and nesting success. Most nestlings had reached at least 50% of their age at fledging by 8 July 2005 and, historically, mortality in the nest is very low after this time. However, four nestlings had not reached 50% of their age at fledgling by this date; thus, I may have overestimated success and productivity in 2005.

Golden Eagles

Golden Eagle nesting territory occupancy and reproductive success. I detected 67 territorial pairs of Golden Eagles in 2005. Of these, 41 pairs produced eggs. I documented egg production by observing 40 incubating eagles and 1 clutch with 2 eggs. I documented 39 successful nests including 18 successful nests with one fledgling and 11 successful nests with two fledglings.

Golden Eagle nesting territory occupancy in 2005 was similar to most other years (Figure 4), but laying rate and success rate (Figure 4) were the highest since 2001 and 1999, respectively. All measures of productivity were higher in 2005 than in the last four to five years (Figures 5).

As expected, Golden Eagle reproduction in Denali in 2005 was higher than the last several years, apparently due to the increasing abundance of snowshoe hare (Figure 6). Like many other northern predators, Golden Eagles in Denali respond to changes in snowshoe hare abundance - more eagles laid eggs (Figure 6) and raised more fledglings in years when the snowshoe hares were abundant.

Golden Eagle nesting phenology. Nesting phenology in 2005 was similar to other years; most clutches were completed by mid-April and most fledglings left their nests by early August. All but four fledglings had reached 50% of their age at fledgling by 8 July 2005.

Age structure of territorial population of Golden Eagles. I made 243 observations of free-flying Golden Eagles in 2005. Of these, I classified one free-flying Golden Eagle as a subadult based on plumage. I observed the subadult Golden Eagle on 27 April 2005 soaring high over the Toklat River. It did not appear to be associated with a nesting territory or another eagle. I assume that many of my observations across the field season are of the same Golden Eagles; therefore, I cannot determine what proportion of the territorial population consists of subadult birds. Because I did not intentionally flush incubating eagles off their nests during the occupancy and activity survey, I could not classify them as adult or subadult. However, I did not observe any subadult Golden Eagles at occupied nests during ground observations, nest visits, or the productivity survey. The lack of observations of subadult Golden Eagles in the study area suggests that the territorial population consists mainly of adults.

The continued stability of nesting territory occupancy and the apparent lack of subadults in the territorial population of Golden Eagles in Denali indicates either high survival of territorial eagles or an ample supply of non-territorial adult Golden Eagles (or floaters) exists to fill voids left by birds that die. Currently, I do not know survival or turnover rates of the territorial population. Without these population parameters, I cannot model population dynamics of the territorial population of Golden Eagles in Denali. I expect that we will be able to identify individual Golden Eagles at nesting territories using DNA extracted from shed feathers. By making annual collections of shed feathers at nesting territories, we will be able to determine turnover rates and perhaps survival rates of the territorial population (Rudnick et al. 2005). This non-invasive, cost-effective technique will enhance our Golden Eagle monitoring program in the near future.

Flushing response of Golden Eagles during aerial surveys. No incubating Golden Eagles exhibited a flush response during aerial surveys in 2005, supporting our assumption that our survey techniques do not adversely affect nesting Golden Eagles. From 1988 to 2004, <1% of incubating eagles flushed off their nest when we approached with a helicopter during the occupancy and activity survey. I assume that our survey technique of slowly approaching nests in full view of the incubating eagle reduces the probability of a flushing or startle response.

Loss of Golden Eagle nesting structures. At least 12 Golden Eagle structures collapsed or became unavailable due to rock falls between 2004 and 2005. One of the largest recorded nests in the study area collapsed between 26 April 2005 and 7 July 2005. This nest contained an incubating adult during the occupancy and activity survey on 26 April 2006 and was one of two known nests in a well-used nesting territory on the southeastern side of Cathedral Mountain.

Gyrfalcons

Gyrfalcon nesting territory occupancy and reproductive success. Gyrfalcon nesting territory occupancy in 2005 was lower than all other years of the study (Figure 7). Success rate was highest since 1989 (Figure 7), but the sample size of successful nest was low (n = 4).

The lack of territorial or breeding Gyrfalcons in the study area in 2005 was surprising because the abundance of Willow Ptarmigan is apparently increasing in the study area. From 1988 to 2004, I observed 9 to 17 pairs of Gyrfalcons in the study area, and observed that nesting success was higher in years when Willow Ptarmigan were abundant (Figure 8). Dixon (1938) also noted the relationship between Gyrfalcons and their prey in this area. Gyrfalcons were common in this area in 1926 when hare and ptarmigan were abundance, but were “absent from their former nesting sites and not one bird was seen during the entire summer” in 1932 when the abundance of hares and ptarmigan were low (Dixon 1938). Although the abundance of Willow Ptarmigan was high in 2005, I found few occupied Gyrfalcon nest sites. These results suggest either that Gyrfalcons were present but went undetected at unknown nest sites, that many Gyrfalcons experienced nest failures before I conducted the occupancy and activity surveys in late April, or that their numbers in the study area decreased substantially from 2004.

Our historic results suggest that Gyrfalcons show some affinity to nest sites and nesting territories. For instance, Gyrfalcons nested for many consecutive years at Eielson Bluffs and Marmot Rock from 1988 to 2005. Apparently, Gyrfalcons have nested successfully in many years near Polychrome since 1941 (Murie 1946), suggesting a strong affinity to some nest sites. However, some historic nest sites were not used recently and I do not know if the birds that used these sites died or moved to another area. Further, we do not know if the same individuals are using the same sites among years and what causes turnover at nest sites.

Recent studies of Gyrfalcons on the Yukon Delta National Wildlife Refuge (NWR) in southwest Alaska, suggest consistent use of nest sites among years, but the same individuals do not use the same sites among years. By extracting DNA from shed feathers, scientists working on the Yukon Delta NWR identifying individual Gyrfalcons and examining turnover rates at nest sites. Their preliminary findings suggest that individual Gyrfalcons show low fidelity to nest sites and that nesting populations exhibit high turnover rates (Travis Booms, University of Alaska (UAF) graduate student, personal communication). I am proposing that we collaborate with UAF and FWS to collect shed feathers at occupied Gyrfalcon nesting territories in 2006 to quantify turnover rates in Denali. Information on turnover rates will provide useful insight for understanding changes of the territorial population of Gyrfalcons in Denali and for future monitoring efforts. Additionally, describing the genetic diversity of Gyrfalcons in Denali will provide valuable information for the ongoing efforts to develop a statewide monitoring program for this species.

Snowshoe hare and Willow Ptarmigan Abundance

My counts of snowshoe hare and Willow Ptarmigan indicated that the abundance of both species increased from 2004 to 2005 (Figure 9). My continuous counts of both species also suggest that the cycles of these species is synchronous in the study area (Figure 9). Many park staff and local community members commented on the abundance of snowshoe hare in the area and biologists recorded an increase in snowshoe hare abundance in other areas of interior Alaska (S. Arthur and S. Dubois, ADFG, and J. Mason, Colorado State University, personal communications). The annual snowshoe hare abundance indices constructed for three areas in interior Alaska indicated that snowshoe hare populations in these areas reached the low point of their cycle in 2003, started increasing in 2004, and continued to increase in 2005 (Figure 10). Based on historic data, snowshoe hare abundance appears to be increasing and this species should reach the peak of their cycle in 2006 or 2007. New efforts to develop a long-term monitoring program for snowshoe hare in Denali (Maggie MacCluskie, NPS, personal communication) should be useful for monitoring the response of Golden Eagles to changes in this important prey resource in the future.

ADDITIONAL OBSERVATIONS

Noteworthy observations made during this project in 2005 include:

• Black-capped Chickadee* (Poecile atricapilla), Boreal Chickadee* (Poecile hudsonica), Horned Lark* (Eremophila alpestris), Ruby-crowned Kinglet* (Regulus calendula), Townsend’s Solitaire* (Myadestes townsendi), Varied Thrush* (Ixoreus naevius), American Robin* (Turdus migratorius), American Pipit* (Anthus rubescens), Yellow-rumped Warbler* (Dendroica coronata), American Tree Sparrow* (Spizella aborea), Savannah Sparrow* (Passerculus sandwichensis), Fox Sparrow* (Passerella iliaca), Dark-eyed Junco* (Junco hyemalis), White-crowned Sparrow* (Zonotrichia leucophrys), Golden-crowned Sparrow* (Zonotrichia atricapilla), Lapland Longspur (Calcarius lapponicus), Snow Bunting (Plectrophenax nivalis), Gray-crowned Rosy Finch* (Leucosticte tephrocotis), White-winged Crossbill* (Loxia leucoptera), Pine Siskin* (Carduelis pinus), Common Redpoll* (Cardeulis flammea), and Pine Grosbeak* (Pinicola enucleator) observed between 26 April and 28 April 2005. An asterisk (*) follow the common name of the species indicates that I heard this species singing.

• Northern Harrier (Circus cyaneus), Sharp-shinned Hawk (Accipiter striatus), Northern Goshawk (Accipiter gentilis), Red-tailed Hawk (Buteo jamaicensis), Rough-legged Hawk (Buteo lagopus), Golden Eagle, Bald Eagle (Haliaeetus leucocephalus), American Kestrel (Falco sparverius), Merlin (Falco columbarius), and Gyrfalcon observed between 26 and 29 April 2005.

• Short-eared Owl (Asio flammeus), Northern Hawk Owl (Surnia ulula), Great Horned Owl (Bubo virginianus), and Boreal Owl (Aegolius funereus) observed between 26 April and 28 April 2005.

• Tree Swallows (Tachycineta bicolor) observed flying over McKinley Park airstrip on 28 April 2005.

• Osprey (Pandion haliaetus) observed hunting and calling over Moose Creek between North Face Lodge and Camp Denali on 23 June 2005. Camp Denali and North Face Lodge staff occasionally observe Osprey in this area each summer (S. Senner, personal communication).

• Short-eared Owls (2 to 3) observed along Denali park road corridor on several trips between 15 June and 15 July 2005. (Note: Staff from Camp Denali and North Face Lodge as well as many bus drivers reported a substantial increase in observations of Short-eared Owls in this area this summer).

• Occupied nest sites of Northern Harrier (n = 8), American Kestrel (n = 4), Merlin (n = 12), Short-eared Owl (n = 2), and Northern Shrike (Lanius excubitor) (n = 4) between 15 June and 8 July 2005.

• Adult Trumpeter Swan (Cygnus buccinator) feeding on pond on east side of upper Sanctuary River east of Double Mountain on 8 July 2005.

• Two successful Peregrine Falcon (Falco peregrinus) nests, each with three fledglings; Toklat River near northern park boundary. The northern most nest site was near the top of a large cut bank on a dirt ledge above a large ice lens; 7 July 2005.

• Two adult Bald Eagles engaged in nest building activities near junction of East Fork and Toklat rivers on 7 July 2005. Nest is located in a large cottonwood tree on the south end of a small island.

• Five grizzly bears (two adults or one female with a three year-old; one female with two yearlings) in Toklat and Polychrome area on 26 April 2005 and three grizzly bears (one lone adult; one female with one yearling) in the Stony Creek area on 28 April 2005.

• Large-bodied mosquitoes present and biting at McKinley Park airstrip on 27 April 2005.

PRESENTATIONS, PAPERS AND OUTREACH ACTIVITIES

Fiscal Year 2005 (October 2004 to September 2005)

Presentations

• Reproductive Success of Golden Eagles in Relation to Landscape Characteristics in Denali National Park, Alaska. University of Alaska and Institute of Arctic Biology, Life Sciences Seminar Series. October 2004. University of Alaska-Fairbanks, Fairbanks, Alaska.

• Short and Sweet: the Post-fledging Dependence Period of Golden Eagles in Denali National Park and Preserve, Alaska. Oral Presentation. Annual Meetings of the Raptor Research Foundation. November 2004, Bakersfield, California.

• Conservation Issues Facing Denali’s Migratory Golden Eagles. Denali Foundation Potluck with a Purpose, Winter Seminar Series, December 2004, Denali Park, Alaska.

• Migratory Golden Eagles Across Alaska’s National Conservation Areas. National Park Service Brown Bag Lunch Speaker Series. March 2005. Fairbanks, Alaska.

• Developing a Long-Term Monitoring Program for Golden Eagles and Passerines in Denali. Denali and ARAMark Seasonal Employee Training Seminar Series. May 2005.

Field Seminars

• Denali’s Amazing Migratory Songbirds. Field Seminar. Denali Institute and the Murie Science and Learning Center. May 2005. Denali National Park and Preserve, Alaska.

• Ecology of Denali’s Birds. Field Seminar. Denali Institute and the Murie Science and Learning Center. June 2005. Denali National Park and Preserve, Alaska.

Peer Reviewed Manuscripts Accepted for Publication

• McCaffery, B.J. and C. McIntyre. 2005. Disparities between Results and Conclusions: Do Golden Eagle Warrant Special Concern Based on Migration Counts in the Western United States? Condor 107:469-473.

• McIntyre, C.L., and M.W. Collopy. 2006. The post-fledging dependence period of migratory Golden Eagles in Denali National Park and Preserve, Alaska. In press. Auk.

• McIntyre, C.L., M.W. Collopy, and M.S. Lindberg. 2006. Survival Probability and Mortality of Migratory Juvenile Golden Eagles from Interior Alaska. In press. J. Wildlife Management.

• McIntyre, C.L., M.W. Collopy, J. Kidd, A. Stickney, and J.Paynter. 2006. Landscape characteristics surrounding Golden Eagle nest sites in Denali National Park and Preserve, Alaska. In press. Journal of Raptor Research.

Manuscripts Accepted for Publication in Non-Peer Reviewed Journals

• McIntyre, C.L., K. Steenhof, M.N. Kochert, and M.W. Collopy. 2006. Long-Term Golden Eagle Studies in Denali National Park and Preserve. In press. Alaska Park Science.

FISCAL YEAR 2006 (October 2005 to September 2006)

The following activities are planned for Fiscal Year 2006:

Databases and Analyses

• Complete database for Golden Eagle and Gyrfalcon monitoring program with Doug Wilder and Al Smith, data managers, Central Alaska Network.

• Develop routine in statistical software program R to detect trends in nesting territory occupancy and breeding success of Golden Eagles and Gyrfalcons in cooperation with Ed Debevec, University of Alaska-Fairbanks.

Fieldwork

• Conduct occupancy and activity surveys in April 2006, nest visits to collect shed feathers in late June and early July 2006. and productivity survey in July 2006.

• Count adult snowshoe hare and Willow Ptarmigan, April to June 2006.

Proposals

• Complete and submit proposal on Golden Eagle genetics project to USGS in collaboration with Sandy Talbot, USGS.

• Develop proposal for NPS funding to determine detectability of Golden Eagles and Gyrfalcons at nesting territories.

Manuscripts in Preparation

• Broad-scale Movements of juvenile Golden Eagles as determined by satellite telemetry.

• Movements of juvenile Gyrfalcons during autumn.

Presentations at Scientific Meetings

• Probability of Survival of Juvenile Migratory Golden Eagles from Denali. Annual meetings of the Raptor Research Foundation, Green Bay, WI, October 2005.

• Long-term Monitoring and Research Studies of Migratory Golden Eagles, Denali National Park, Alaska. Staff seminar, Acopian Center for Conservation, Hawk Mountain Sanctuary, Kempton, PA. November 2005.

• An Introduction to the Natural History of Golden Eagles in Interior Alaska. Natural History of Alaska undergraduate class, University of Alaska-Fairbanks. November 2005.

• Long-term Monitoring of Golden Eagle and Gyrfalcon Reproductive Success in Denali National Park, Alaska. Denali Science Symposium, September 2006.

• Probability of Survival of Juvenile Migratory Golden Eagles from Denali National Park and Preserve, Alaska. The Wildlife Society, annual meeting, Anchorage, Alaska. September 2006.

• Using Satellite Telemetry to Study the Broad-scale Movements of Migratory Golden Eagles in North America. Migration Symposium, North American Ornithological Conference, Vera Cruz, Mexico, October 2006.

ACKNOWLEDGMENTS

I thank the Vital Signs Monitoring Program of the Central Alaska Network, National Park Service and Denali National Park and Preserve for funding this project. Special thanks to Mike Terwillinger and Chris Mauer, both of Quicksilver Air, Fairbanks, Alaska for providing great piloting during aerial surveys, Jane Bryant and Nikki Demers for helping with the occupancy and activity survey, and Ryan Drum and Sally Andersen for assisting with nest visits. Steve Dubois and Jeff Mason provided data on snowshoe hare abundance near Delta Junction, Alaska. Maggie MacCluskie (NPS) reviewed an earlier draft of this report and provided comments that greatly improved the report.

LITERATURE CITED

Dixon, J.S. 1938. Birds and Mammals of Mount McKinley National Park, Alaska. Fauna of the National Parks of the United States, Fauna Series No. 3. United States Government Printing Office, Washington, DC.

Kochert, M.N., and K. Steenhof. 2002. Golden Eagles in the U.S. and Canada; status, trends, and conservation challenges. Journal of Raptor Research 36 (1 Supplement):32-40.

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Figure 1. General location of study area for Golden Eagle monitoring project, Denali National Park and Preserve, Alaska. The study area is approximately 2,400 km2.

Figure 2. Flow-charts illustrating decision-making process for determining occupancy of nesting territories and breeding success. The top flow chart refers to the nesting territory and nest structure and the bottom flow chart refers to the pair of Golden Eagles or Gyrfalcons.

Occupancy unknown

No fledglings (failed nest)

Fledglings

(Successfulnest)

No eggs

in nest

Eggs in nest

(Occupied nest)

No evidence of territorial pair (unoccupied territory)

Territorial pair

(Occupied territory)

Nesting territory

Territorial Pair

No eggs (Non-laying pair)

Eggs (Laying pair)

No fledglings(Failed pair)

At least one fledgling (successful pair)

Figure 3. Number of Golden Eagle and Gyrfalcon nesting territories annually monitored in Denali National Park and Preserve, Alaska, 1988 to 2005.

Figure 4. Annual Golden Eagle nesting territory occupancy rate, laying rate, and success rate, Denali National Park and Preserve, Alaska, 1988 to 2005.

Figure 5. Annual measurements of Golden Eagle productivity, Denali National Park and Preserve, Alaska, 1988 to 2005. Overall productivity (OPP) is the number of fledglings produced per occupied territory (or territorial pair), productivity per occupied nest (PPO) is the number of fledglings produced per occupied nest (or laying pair), and mean brood size (MBS) is the number of fledglings produced per successful nest (or successful pair).

Figure 6. Annual Golden Eagle laying rate (percentage of territorial pairs with eggs) in relation to the number of snowshoe hares detected each field day, Denali National Park and Preserve, Alaska, 1988 to 2005.

Figure 7. Annual nesting territory occupancy and laying rates (%) of Gyrfalcons, Denali National Park and Preserve, Alaska, 1988 to 2005.

Figure 8. Annual Gyrfalcon success rate (percentage of laying pairs raising at least one fledgling) in relation to the number of Willow Ptarmigan detected each field day, Denali National Park and Preserve, Alaska, 1988 to 2005.

Figure 9. Annual abundance indices of snowshoe hare and Willow Ptarmigan, Denali National Park and Preserve, Alaska, 1988 to 2005.

Figure 10. Indices of snowshoe hare abundance from three different sources in interior Alaska. The Denali index, shown on the left side of the graph, is constructed using the number of adult snowshoe hares detected each field day between April and June. The Delta and Donnelly indices, shown on the Y-axis on the right side of the graph, are constructed using the number of snowshoe hares detected on Breeding Bird Survey counts (24.5-mile route).

Appendix A. Terminology used to describe nesting territory occupancy and reproductive success for Golden Eagles and Gyrfalcons in Denali National Park and Preserve, Alaska (following Steenhof 1987).

Appendix B. Metrics calculated annually to monitor nesting territory occupancy and reproductive success of Golden Eagles and Gyrfalcons in Denali National Park and Preserve, Alaska (following Steenhof 1987 and Steenhof et al. 1997).

1 I calculate three metrics of productivity annually to make comparisons with other study areas.