Identification

Perching: Large, dark raptor with large beak and golden neck feathers. Immatures (less than 5 years old) have a prominent white stripe at base of tail.

Flying: Dark brown underneath. Dark tail unbanded to faintly banded. Long straight wings with long "fingers" (primaries); "lazy" soaring flight. Immatures show white tail stripe and white underwing spots at the wrists.

Nesting Habitat

Cliffs or trees, generally in open country. Nesting cliffs are usually sheer and often several hundred feet high. Cliffs often contain several stick nests, 3-10' wide; a single pair will move from one nest to another on the same cliff face from year to year. Active nests usually show some greenery (Douglas-fir or pine boughs). Pairs defend nesting territories of several square miles.

Nesting Dates

Courtship: January to May

Incubation: late February to June

Dependent nestlings: early April to mid-July

Incubation period is 41-45 days. Young fledge 72-84 days after hatching but remain dependent on parents for several months after fledging.

Statewide Distribution and Population

There are probably 200-500 breeding pairs in Colorado. The statewide population appears to have changed little during the past 100 years. Golden eagles nest in virtually every part of the state, with highest densities in the northern Front Range foothills and western plateaus. Nesting pairs are widely scattered across the eastern plains.

State and Federal Status

Federally protected under Bald and Golden Eagle Protection Act. Colorado State Wildlife Action Plan Tier 1 species.

Search and Nest Monitoring Protocol

Begin to search for active nests, looking for fresh greenery, in late February. Visit active nest sites for 2-3 hours every 2 weeks (supplementing on weekends to monitor nests for disturbance) until young have fledged. Observation points should be at least 800 m from nests.

Recommended Nest Buffer Area

CPW recommends no surface occupancy (beyond that which historically occurred in the area) within a 400 m radius of the nest site and associated alternate nests, and no human encroachment within 800 m of the nest and any alternate nests from 1 February to 15 July.

References

Bent, A. C. 1937. Life histories of North American birds of prey, part 1. U.S. National Museum Bulletin 167, Washington, D.C.

Craighead, J. J., and F. C. Craighead. 1956. Hawks, owls, and wildlife. Stackpole Books, Harrisburg, PA.

Johnsgard, P. A. 1990. Hawks, eagles, and falcons of North America. Smithsonian Institution press, Washington, D.C.

Jollie. M. T. 1945. Notes on raptors of the Boulder area, Colorado. Condor 47: 38-39.

Kingery, H. E., ed. 1998. Colorado breeding bird atlas. Colorado Bird Atlas Partnership, Denver.

Snow, C. 1973. Golden eagle. Habitat management series for unique or endangered species. U.S. Department of the Interior Bureau of Land Management Technical Note 239.

True, D. 1980. A family of eagles. Everett House, New York.

Wickersham, L.E. 2016. The Second Colorado Breeding Bird Atlas. Colorado Bird Atlas Partnership, Denver.