Index of Species Information

WILDLIFE SPECIES:  Aquila chrysaetos

Introductory

WILDLIFE SPECIES: Aquila chrysaetos
AUTHORSHIP AND CITATION : Tesky, Julie L. 1994. Aquila chrysaetos. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available: http://www.fs.fed.us/database/feis/ [].
ABBREVIATION : AQCH COMMON NAMES : golden eagle TAXONOMY : The currently accepted scientific name for the golden eagle is Aquila chrysaetos (Linnaeus) [1]. The following five races are recognized [9,21]: Aquila chrysaetos chrysaetos (Linnaeus) Aquila chrysaetos hameryi (Severtza) Aquila chrysaetos daphanea (Menzbir) Aquila chrysaetos canadensis (Linnaeus) Aquila chrysaetos japonica (Severtza) Aquila chrysaetos canadensis is the only race that occurs in North America [9,21]. ORDER : Falconiformes CLASS : Bird FEDERAL LEGAL STATUS : The gold eagle is federally protected under the Bald Eagle Protection Act of 1962 [31]. OTHER STATUS : Declines in golden eagle populations have been pronounced in coastal southern California. The golden eagle is listed as a species of special concern in Washington and Montana. Golden eagles are common and populations are presumably stable in other western states [13]. Golden eagles are recognized as an endangered species by Maine, New Hampshire, and New York. Other states in the Northeast either designate the golden eagle as a former resident, an occasional transient visitor, or extirpated [26].

WILDLIFE DISTRIBUTION AND OCCURRENCE

WILDLIFE SPECIES: Aquila chrysaetos
GENERAL DISTRIBUTION : In North America the golden eagle breeds from northern and western Alaska east to Labrador and south to southern Alaska, Baja California, western and central Texas, western Oklahoma, western Kansas, and the highlands of northern Mexico (south to Durango, Guanauato, and Nuevo Leon) [1,8]. A remnant eastern population of golden eagles extends from Quebec into the Appalachian Mountains [9]. The golden eagle has never been common in the eastern United States. Fewer than 30 historical breeding territories are documented in the Northeast, primarily in New York, New Hampshire, and Maine [26]. The golden eagle winters from south-central Alaska and the southern portions of the Canadian provinces south throughout the breeding range to Mexico, rarely to coastal South Carolina [8,9]. ECOSYSTEMS : FRES10 White-red-jack pine FRES11 Spruce-fir FRES12 Longleaf-slash pine FRES13 Loblolly-shortleaf pine FRES14 Oak-pine FRES15 Oak-hickory FRES16 Oak-gum-cypress FRES17 Elm-ash-cottonwood FRES18 Maple-beech-birch FRES19 Aspen-birch FRES20 Douglas-fir FRES21 Ponderosa pine FRES22 Western white pine FRES23 Fir-spruce FRES24 Hemlock-Sitka spruce FRES25 Larch FRES26 Lodgepole pine FRES27 Redwood FRES28 Western hardwoods FRES29 Sagebrush FRES30 Desert shrub FRES31 Shinnery FRES32 Texas savanna FRES33 Southwestern shrubsteppe FRES34 Chaparral-mountain shrub FRES35 Pinyon-juniper FRES36 Mountain grasslands FRES37 Mountain meadows FRES38 Plains grasslands FRES39 Prairie FRES40 Desert grasslands FRES41 Wet grasslands FRES42 Annual grasslands FRES44 Alpine STATES :
AL AK AZ AR CA CO CT DE FL GA ID IL IN IA KS KY LA ME MD MA MI MN MS MO MT NE NV NH NJ NM NY NC ND OH OK OR PA RI SC SD TN TX UT VT VA WA WV WI WY AB BC MB NB NF NT NS ON PE PQ SK YT MEXICO
BLM PHYSIOGRAPHIC REGIONS : 1 Northern Pacific Border 2 Cascade Mountains 3 Southern Pacific Border 4 Sierra Mountains 5 Columbia Plateau 6 Upper Basin and Range 7 Lower Basin and Range 8 Northern Rocky Mountains 9 Middle Rocky Mountains 10 Wyoming Basin 11 Southern Rocky Mountains 12 Colorado Plateau 13 Rocky Mountain Piedmont 14 Great Plains 15 Black Hills Uplift 16 Upper Missouri Basin and Broken Lands KUCHLER PLANT ASSOCIATIONS : occurs in most Kuchler Plant Associations SAF COVER TYPES : occurs in most SAF cover types SRM (RANGELAND) COVER TYPES : NO-ENTRY PLANT COMMUNITIES : The golden eagle occupies a variety of plant communities including tundra, alpine meadows, coniferous forests, shortgrass prairies and other grasslands, sagebrush (Artemisia spp.) plateaus, sagebrush steppe with scattered ponderosa pine (Pinus ponderosa) and cottonwoods (Populus spp.), shrublands, oak (Quercus spp.) woodlands, pinyon-juniper (Pinus spp.-Juniperus spp.) woodlands, and semidesert canyons [6,7,21,27,28]. In California the golden eagle favors grasslands, shrublands with tree saplings, and open-canopy blue oak (Quercus douglasii) woodlands. In late summer the golden eagle is often seen above timberline in California [27]. Major vegetation types occupied by the golden eagle during the nesting season in the Snake River Birds of Prey Area, Idaho, from 1977 through 1979 include big sagebrush (Artemisia tridentata), grassland (Poa and Bromus spp.), and shadscale (Atriplex confertifolia) [6].

BIOLOGICAL DATA AND HABITAT REQUIREMENTS

WILDLIFE SPECIES: Aquila chrysaetos
TIMING OF MAJOR LIFE HISTORY EVENTS : Age at sexual maturity - Golden eagles are sexually mature at 4 or more years of age [16]. Breeding season - The golden eagle breeding season generally occurs from mid-January to mid-September, but varies according to geographic area [22,27]. Clutch size and incubation - The golden eagle lays one to three eggs, with two eggs most common [9,21,27]. The eggs are incubated for 35 to 45 days [9]. Fledging - Nestlings fledge at 9 to 10 weeks and remain in the vicinity of the nest. The parents provide food for the fledglings until they are about 14 weeks old or older [9]. Migration - Migration varies with population and cohort and is a function of both food supply and climate. Golden eagles in the subarctic and at least some golden eagles of all ages in northern boreal areas migrate. They travel south along high ridges in the Intermountain West during September and October. In the East they traverse the ridges of the Appalachians to the southern highlands from September through November. In a zone near the United States-Canada boundary, resident breeders and older prebreeders migrate short distances in severe winters and/or when food is scarce [21]. In the mountainous West, golden eagles often move down from the mountains onto the plains and valleys during the winter [8]. Breeding golden eagles prefer to maintain their nesting-hunting territories or travel the shortest distance necessary to survive prolonged cold or heat, while older prebreeders may be less tied to specific locations. Birds of the youngest cohort are often migratory. In the arid Southwest, golden eagles move to high elevations after breeding [21]. Longevity - Golden eagles in captivity have lived 41 to 48 years, but it is unlikely that many live that long in the wild [9]. PREFERRED HABITAT : The golden eagle inhabits open country from barren areas to open coniferous forests. They are primarily in hilly and mountainous regions, but also in rugged deserts, on the plains, and in tundra. The golden eagle prefers cliffs and large trees with large horizontal branches and for roosting and perching [8]. Nesting habitat - The golden eagle nests on cliff ledges, preferably overlooking grasslands; 10 to 100 feet (3-30 m) above ground in dead or live trees; in artifical structures; or on the ground [8,7,27]. In western mountains, golden eagles nest at elevations of 4,000 to 10,000 feet (1,219-3,048 m). Pairs may use the same nest year after year or use alternate nests in successive years [8]. Golden eagles are most likely to use trees for nesting if cliff sites are unavailable. In the Powder River Basin of Wyoming, 67 percent of golden eagle nests were found in deciduous trees; 22 percent in ponderosa pine (Pinus ponderosa); and 4 percent on the ground [19]. Near Medicine Bow, Wyoming, 60 percent of golden eagle nests were on cliffs [17]. In Campbell and Converse counties, Wyoming, 57 percent of occupied nests were found in deciduous trees along drainages and 25 percent were in ponderosa pine trees. The remaining nests were on rock outcrops and peaks (8%), artifical structures (7%), and creekbanks (3%). In Campbell and Converse counties golden eagles preferred to nest in large pines when both cottonwoods and pines were available. Large dense stands of both cottonwoods and pines were avoided as nest areas. Isolated or scattered trees were preferred [22]. In the Coast Ranges of California, the golden eagle nests almost exclusively in trees [21]. Foraging habitat - The golden eagle generally forages in open habitats where rabbits and small rodents are available. During the nesting season the golden eagle usually forages within 4.4 miles (7 km) of the nest [7]. Trees, live or dead, are often used for perches if they are near open areas where prey can be easily seen [30]. Winter habitat - Winter habitat requirements for the golden eagle are very similar to nesting habitat requirements. In the East the golden eagle generally winters on coastal plains and wetlands [7]. COVER REQUIREMENTS : Golden eagles use elevated nest sites, especially sheltered ledges on secluded cliffs, that are isolated from human disturbance and are close to hunting areas [8,24]. Golden eagles are most efficient predators in open areas where winds and thermal updrafts aid flying. They are less efficient where shrub and/or tree cover increases. Abundant shrub cover provides hiding and escape cover for prey. Physical obstructions close to the ground make hunting difficult [18]. FOOD HABITS : The golden eagle feeds primarily on mammals. It feeds mainly on lagomorphs and small rodents, but also on marmots (Marmota spp.), prairie dogs (Cynomys spp.), ground squirrels (Spermophilus spp.), weasels (Mustela spp.), woodrats (Neotoma spp.), skunks, mice, and rarely, large mammals. The golden eagle also eats grouse, pheasants (Phasianus spp.), owls, hawks, rock dove (Columba livia), magpies (Pica spp.), and other birds as well as rattlesnakes, frogs, carrion, and occasionally, fish [4,8,9,21,27]. PREDATORS : NO-ENTRY MANAGEMENT CONSIDERATIONS : Direct and indirect human-caused mortality, disturbance, and the elimination of prey by habitat alteration are the main factors limiting golden eagle populations [28]. Shooting, poisoning, trapping, electrocution and/or collision with powerlines, and pesticide contamination have all been identified as causes of the decline of golden eagle populations. In addition, recreational activities may disturb breeding, wintering, and migration activities, disrupting and often reducing the population [9]. Habitat management for the golden eagle primarily consists of protecting areas used for nesting, resting, and foraging, and protecting habitat used by the prey base [9]. Some researchers suggest placing 0.25- to 2-mile (0.4-3.2 km) buffer zones around nest sites in areas undergoing energy development or increased recreational use. Nest-site protection is only advantageous if the prey base remains adequate following development. Many types of development such as oil, gas, and geothermal exploration; pipeline and road construction; and development of campgrounds and interpretive facilities on public lands remove vegetation from small areas. If important prey concentrations such as ground squirrel colonies are avoided, golden eagles should be able to coexist with these developments provided nest sites are undisturbed [25]. Nesting habitat can be enhanced by providing artifical nest structures in areas where natural nesting sites have been eliminated. Population enhancement through captive breeding, foster parenting, and rehabilitation and reintroduction are feasible techniques where suitable habitat for golden eagles is unoccupied [9]. Golden eagles are sensitive to human disturbance and are likely to abandon their nests during the incubation period if disturbed [9,21]. Human disturbance was responsible for 85 percent of golden eagle nesting failures along the Front Range of the Rockies in Wyoming, Colorado, and in New Mexico [21]. Placing seasonal restrictions on recreational activities and limiting human access in nesting areas can minimize the chance of disturbance [5,9]. Some current laws have reduced human-caused hazards to golden eagles. As of February 1972, use of poisons on public lands has been banned by Executive Order. Some animal trapping groups have established policies against placing leg-hold traps near open bait, and some states have laws prohibiting open bait trapping [9]. The problem of golden eagles being electrocuted by powerlines has been greatly reduced during the past decade through cooperative efforts of government agencies, conservation organizations, and the electric industry. This cooperation is now being extended into positive golden eagle habitat management by power companies [20]. Golden eagles are very susceptible to organochlorine pesticides and many other environmental contaminants. Since jackrabbits and other herbivores eaten by golden eagles accumulate low pesticide levels, golden eagles accumulate higher levels via food-chain concentration. Another major threat to golden eagle populations is lead toxicosis, which has been identified as a cause of golden eagle deaths. A preliminary study of a population in southern California reported that 26 of 66 golden eagles (39%) had blood lead levels greater than 0.2 ppm, indicating exposure to environmental lead [13]. Serious golden eagle depredation of livestock is usually infrequent and localized; however, livestock predation has sometimes become a problem for ranchers [18]. While a potential problem may occur anywhere golden eagles and livestock coexist, depredation is most severe on lambs in open range, most notably in Montana and New Mexico. Because golden eagles are protected under federal law, options for damage control efforts are limited and highly restricted [23]. In other areas, such as California, golden eagle depredation of livestock appears minor [13]. Some researchers suggest that golden eagles are beneficial to livestock interests because a large percentage of their diet is made up of rabbits, which compete with livestock for forage. Eight to twelve jackrabbits consume enough forage to support one sheep. The number of rabbits and rodents killed by golden eagles translates into a sizeable quantity of forage [18].

FIRE EFFECTS AND USE

WILDLIFE SPECIES: Aquila chrysaetos
DIRECT FIRE EFFECTS ON ANIMALS : Fire reduces golden eagle reproductive success if the fire crowns in occupied nest trees [15]. Fires that kill or otherwise alter unoccupied nest trees may disrupt reproduction if acceptable nest trees are few. Low-severity fires probably have little direct effect on golden eagles. Landers [15] commented that light winter burning probably does no substantial harm [15]. HABITAT RELATED FIRE EFFECTS : The golden eagle occurs in the following six major fire-dependent plant associations in the western United States: grassland, semidesert grassland-shrub, sagebrush-grassland, pinyon-juniper woodland, and ponderosa pine and Douglas-fir (Pseudotsuga menziesii) forests [29]. In addition to potentially affecting nest trees, fire may kill perch and roosting trees. These snags are used by golden eagles for nesting, perching and/or roosting. Use of trees probably depends more on proximity to prey than condition (live or dead). Migrating golden eagles use fire-killed snags near openings for perching and roosting in subalpine areas of Glacier National Park, Montana [30]. Fires probably enhance the prey base and hunting efficiency of golden eagles. Regular burning helps to keep habitats in a suitable condition for many prey species of the golden eagle and increases hunting efficiency [15]. In forested areas of the East, golden eagles forage on burns, though they may prefer bogs [21]. Golden eagles were seen using recently burned sites in the Lincoln National Forest, New Mexico. Golden eagles there were probably taking advantage of abundant prey associated with the growth of new vegetation on the burned site [29]. Fire suppression in this century has contributed to the loss of golden eagle breeding pairs in the Appalachian Mountains of the eastern United States. Historically, open areas used by golden eagles for foraging in those mountains were maintained by fire. After full suppression policies began, the openings reverted to brush and eventually to forest. Today, there are few openings in the Appalachian Mountains; as a result, the golden eagle has almost disappeared [24]. FIRE USE : In the southeastern United States, mountain balds are burned to help maintain prey populations for the golden eagle [15].

REFERENCES

WILDLIFE SPECIES: Aquila chrysaetos
REFERENCES : 1. American Ornithologists' Union. 2004. The A.O.U. check-list of North American birds, 7th edition, [Online]. American Ornithologists' Union (Producer). Available: http://www.aou.org/checklist/index.php3 [2005, January 10]. [50863] 2. Bent, Arthur Cleveland. 1961. Life histories of North American birds of prey. Part 2. New York: Dover Publications, Inc. 482 p. [22362] 3. Bernard, Stephen R.; Brown, Kenneth F. 1977. Distribution of mammals, reptiles, and amphibians by BLM physiographic regions and A.W. Kuchler's associations for the eleven western states. Tech. Note 301. Denver, CO: U.S. Department of the Interior, Bureau of Land Management. 169 p. [434] 4. Brown, Bryan T. 1992. Golden eagles feeding on fish. Journal of Raptor Research. 26(1): 36-37. [22173] 5. Call, Mayo. 1979. Habitat management guides for birds of prey. Techical Note 338. Denver, CO: U.S. Department of the Interior, Bureau of Land Management, Denver Service Center. 70 p. [22451] 6. Collopy, Michael W. 1984. Parental care and feeding ecology of golden eagle nesting. Auk. 101(4): 753-760. [22283] 7. Cooperrider, Allen Y.; Boyd, Raymond J.; Stuart, Hanson R., eds. 1986. Inventory and monitoring of wildlife habitat. Denver, CO: U.S. Department of the Interior, Bureau of Land Management, Service Center. 858 p. [3441] 8. DeGraaf, Richard M.; Scott, Virgil E.; Hamre, R. H.; [and others]. 1991. Forest and rangeland birds of the United States: Natural history and habitat use. Agric. Handb. 688. Washington, DC: U.S. Department of Agriculture, Forest Service. 625 p. [15856] 9. Dunstan, Thomas C. 1989. The golden eagle. In: Audubon wildlife report: 1989/1990: 499-511. On file with: U.S. Department of Agriculture, Forest Service, Intermountain Research Station, Fire Sciences Laboratory, Missoula, MT. [22392] 10. Eyre, F. H., ed. 1980. Forest cover types of the United States and Canada. Washington, DC: Society of American Foresters. 148 p. [905] 11. Garrison, George A.; Bjugstad, Ardell J.; Duncan, Don A.; [and others]. 1977. Vegetation and environmental features of forest and range ecosystems. Agric. Handb. 475. Washington, DC: U.S. Department of Agriculture, Forest Service. 68 p. [998] 12. Goodwin, Gregory A. 1976. Golden eagle predation on pronghorn antelope. Auk. 94(4): 789-790. [19315] 13. Harlow, David L.; Bloom, Peter H. 1989. Buteos and the golden eagle. In: Proceedings of the western raptor management symposium and workshop; 1987 October 26-28; Boise, ID. Scientific and Technical Series No. 12. [Place of publication unknown]: National Wildlife Federation: 102-110. [22407] 14. Kuchler, A. W. 1964. Manual to accompany the map of potential vegetation of the conterminous United States. Special Publication No. 36. New York: American Geographical Society. 77 p. [1384] 15. Landers, J. Larry. 1987. Prescribed burning for managing wildlife in southeastern pine forests. In: Dickson, James G.; Maughan, O. Eugene, eds. Managing southern forests for wildlife and fish: a proceedings; [Date of conference unknown]; [Location of conference unknown]. Gen. Tech. Rep. SO-65. New Orleans, LA: U.S. Department of Agriculture, Forest Service, Southern Forest Experiment Station: 19-27. [11562] 16. Lee, David S.; Spofford, Walter R. 1990. Nesting of golden eagles in the central and southern Appalachians. Wilson Bulletin. 102(4): 693-698. [22325] 17. MacLaren, Patricia A.; Anderson, Stanley H.; Runde, Douglas E. 1988. Food habits and nest characteristics of breeding raptors in southwestern Wyoming. Great Basin Naturalist. 48(4): 548-553. [22268] 18. Matchett, Marc R.; O'Gara, Bart W. 1991. Golden eagles and the livestock industry: an emotionally charged issue. Western Wildlands. 17(1): 18-24. [22519] 19. Menkens, George E.; Anderson, Stanley H. 1983. How selective are golden eagles when choosing a nest site?. Journal of the Colorado-Wyoming Academy of Science. 15(1): 55-56. Abstract. [22518] 20. Nelson, Morlan W. 1982. Human impacts on golden eagles: a positive outlook for the 1980's and 1990's. Raptor Research. 16(4): 97-103. [22517] 21. Palmer, Ralph S., editor. 1988. Handbook of North American birds. Volume 5. New Haven, CT: Yale University Press. 463 p. [22303] 22. Phillips, Robert L.; Beske, Alan E. 1990. Distribution and abundance of golden eagles and other raptors in Campbell and Converse Counties, Wyoming. Fish and Wildlife Technical Report 27. Washington, DC: U.S. Department of the Interior, Fish and Wildlife Service. 31 p. [15473] 23. Phillips, Robert L.; Fall, Michael W. 1990. Control methods and their future application in predation management. In: Giusti, G. A.; Timm, R. M.; Schmidt, R. H., eds. Predator management in north coastal California: Proceedings of a workshop; 1990 March 10-11; Hopland, CA. Hopland Field Station Publication 101. Berkeley, CA: University of California: 65-70. [22290] 24. Spofford, Walter R. 1971. The golden eagle--rediscovered. Conservationist. 26(1): 6-8. [22516] 25. Suter, Glenn W., II; Joness, Jan L. 1981. Criteria for golden eagle, ferruginous hawk, and prairie falcon nest site protection. Raptor Research. 15(1): 12-18. [22515] 26. Todd, Charles S. 1989. Golden eagle. In: Northeast raptor management symposium and workshop: Proceedings; 1989 May 16-18; Syracuse, NY. National Wildlife Federation Scientific and Technical Series 13. Washington, DC: National Wildlife Federation: 65-70. [22176] 27. Verner, Jared; Boss, Allan S., tech. coords. 1980. California wildlife and their habitats: western Sierra Nevada. Gen. Tech. Rep. PSW-37. Berkeley, CA: U.S. Department of Agriculture, Forest Service, Pacific Southwest Forest and Range Experiment Station. 439 p. [10237] 28. Wassink, Jan. 1991. Birds of the central Rockies. Missoula, MT: Mountain Press Publishing. 179 p. [22307] 29. Lehman, Robert N.; Allendorf, John W. 1989. The effects of fire, fire exclusion and fire management on raptor habitats in the western United States. In: Proceedings of the western raptor management symposium and workshop; 1987 October 26-28; Boise, ID. Scientific and Technical Series No. 12. Washington, DC: National Wildlife Federation: 236-244. [22324] 30. McClelland, B. R. 1994 [pers. comm.] 31. U.S. Department of the Interior, Fish and Wildlife Service. 1978. Bald Eagle Protection Act. 16 U.S.C. 668-668c. FWS/LE ENF 4. Washington, DC. 2 p. [23844]


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