America’s “Other” Eagle

 Golden Eagle at Swan Falls  Photo credit: USDOT FHA America's Byways

 

Submitted by: Mark Miller

With a wingspan of more than seven feet, the golden eagle is North America’s largest bird of prey. They get their name from the golden feathers on the back of their head and neck.  In contrast to their cousin, the bald eagle, golden eagles prefer less forested, more open habitat and avoid developed areas. They find this habitat in central and eastern Washington. Their most common prey are small to medium-sized mammals including black-tailed jackrabbits, ground squirrels and yellow-bellied marmots.  Golden eagles will also take birds, larger mammals, fish, reptiles, and domestic livestock and feed on carrion (dead animals). However, golden eagles show a strong preference for jackrabbits, even when jackrabbit populations are low.  In fact, golden eagle populations in some parts of the U.S. have a tendency to cycle on a 10-year basis with jackrabbit populations.

Any real estate agent will tell you the three most important factors for buying a home are LOCATION, LOCATION, LOCATION.  This holds true for golden eagles.   The ideal nesting home site for a golden eagle pair is a cliff or large tree in a quiet neighborhood, close to the grocery store (hunting grounds), with a panoramic view of their environs.  Golden eagles are less gregarious than bald eagles, so you will rarely see them in large concentrations.  They range from the arctic to the desert southwest and are more common west of the Mississippi, although they do occur in the eastern United States.

Population trends for golden eagles have been difficult to determine due to a lack of long-term monitoring studies of golden eagle abundance in the United States prior to 2003.  There is a general consensus that golden eagle populations are declining in many areas due to the usual cast of suspects:  loss of habitat, reduction in prey particularly jackrabbits, collisions with vehicles, wind turbines or other structures, electrocution at power poles, intentional and unintentional poisoning and climate change. 

Habitat loss comes from a variety of sources.  As human activity and development increase, pressure is put on golden eagles.  Urbanization, agriculture, mining and wind farms can reduce golden eagle habitat.  Exotic plant species invading native shrub steppe habitat in eastern Washington can increase the frequency and intensity of wildfires and cause negative effects to the plant community and to jackrabbit populations that golden eagle depend.  Non-native cheatgrass is the chief culprit.  Climate change might also contribute to current and future negative effects to golden eagles, particularly in semi-arid and arid ecosystems.

Golden eagles are also being poisoned from ingesting fragments of lead shot or bullets from hunter- killed animals, particularly deer, ground squirrels, upland game birds and waterfowl.  Even tiny amounts of ingested lead can have fatal effects on eagles.  Switching to non-toxic copper bullets can reduce lead poisoning in golden eagles. (http://www.nps.gov/pinn/naturescience/upload/USGS_lead_poisoning_wild_birds_2009.pdf)

Golden eagles are protected by the Migratory Bird Treaty Act in North America and the Bald and Golden Eagle Protection Act (BGEPA) in the U.S.  BGEPA prohibits “take” of eagles without a permit.  “Take” includes pursuing, shooting, shooting at, poisoning, wounding, killing, capturing, trapping, collecting, molesting or disturbing. The BGEPA prohibits “take,” or any of these actions, on individuals, their parts, nests or eggs. (http://www.fws.gov/midwest/midwestbird/eaglepermits/bagepa.html)

The U.S. Fish and Wildlife Service has provided funding to the Washington Department of Fish and Wildlife (http://wdfw.wa.gov/) to locate and monitor known nesting territories in Washington during the 2013 breeding season.  Completion of this study will give us valuable information regarding the number of territories occupied and the number of young golden eagles produced.