The Golden Eagle (Aquila chrysaetos) is one of the best known birds of prey in the Northern Hemisphere.
Most subspecies of Golden Eagle vary in the range from 65 to 100 cm, wingspan can range from 150 to 240 cm, and weight is from 2.5 to 7 kg (5.5–15.5 lb). The plumage colours range from black-brown to dark brown, with a striking golden-buff crown and nape, which give the bird its name. The upper wings also have an irregular lighter area. Immature birds resemble adults, but have a duller more mottled appearance. Also they have a white-banded tail and a white patch at the carpal joint that gradually disappear with every moult until full adult plumage is reached in the fifth year.
Golden eagle prey includes marmots, hares and mice, and sometimes birds, martens, foxes, small tortoises, young deer, and livestock including lambs and young goats. During winter months when prey is scarce, Golden Eagles scavenge on carrion to supplement their diet. Sometimes when no carrion is available golden eagles will hunt down owls, hawks, falcons, and large ungulates. Golden eagles are avian apex predators, meaning a healthy adult is not preyed on.
Golden Eagles have very good eyesight and can spot prey from a long distance. The Golden Eagle has a resolving power 8x more powerful than a human.
Golden Eagles usually mate for life. They build several eyries within their territory and use them alternately for several years. These nests consist of heavy tree branches, upholstered with grass when in use. Old eyries may be 2 metres (6.6 ft) in diameter and 1 metre (3.3 ft) in height, as the eagles repair their nests whenever necessary and enlarge them during each use. If the eyrie is situated on a tree, supporting tree branches may break because of the weight of the nest. Certain other animals – birds and mammals too small to be of interest to the huge raptor – often use the nest as shelter.
Species: A. chrysaetos
The female lays two black eggs between January and September (depending on the locality). They start incubation immediately after the first egg is laid, and after 45 days on average the young hatch. They are entirely white and are fed for fifty days before they are able to make their first flight attempts and eat on their own. In most cases only the older chick survives, while the younger one dies without leaving the eyrie. This is due to the older chick having a few days' advantage in growth and consequently winning most squabbles for food.
At one time, the Golden Eagle lived in temperate Europe, North Asia, North America, North Africa and Japan. In most areas this bird is now a mountain-dweller. In North America the situation is not as dramatic, but there has still been a noticeable decline. The main threat is habitat destruction which by the late 19th century already had driven Golden Eagles from some regions they used to inhabit.
Available habitat and food are the main limiting factor nowadays. Collisions with power lines have become an increasingly significant cause of mortality since the early 20th century. On a global scale, the Golden Eagle is not considered threatened by the IUCN mainly thanks to the large Asian and American populations.
* BirdLife International (2004). Aquila chrysaetos. 2006 IUCN Red List of Threatened Species. IUCN 2006. Retrieved on 2006-05-12. Database entry includes justification for why this species is of least concern
* e-CFR (2008): 50 CFR 22 - Eagle Permits.
* Henninger, W.F. (1906): A preliminary list of the birds of Seneca County, Ohio. Wilson Bull. 18(2): 47-60.
* Gates, Alan (1990): The Call of the Wind. Falconers & Raptor Conservation Magazine 
* Linnaeus, Carl (1758): 41.2. Falco chrysaetos. In: Systema naturae per regna tria naturae, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis (10th ed., vol.1): 88. Laurentius Salvius, Holmius (= Stockholm).
* Gordon, Seton (1955): The Golden Eagle: King of Birds. Citadel Press, New York.
* Snow, David W.; Perrins, Christopher M.; Doherty, Paul & Cramp, Stanley (1998): The complete birds of the western Palaearctic on CD-ROM. Oxford University Press
* RTÉ News (2007): Golden Eagle hatches in Donegal. Version of 2007-MAY-30. Retrieved 2008-FEB-14.
* Sánchez Marco, Antonio (2004): Avian zoogeographical patterns during the Quaternary in the Mediterranean region and paleoclimatic interpretation. Ardeola 51(1): 91-132.
* United States District Court for the District of Nevada (USDCDN) (1986): 649 F.Supp. 269 - U.S. v. Thirty-Eight Golden Eagles.
* United States Fish and Wildlife Service Office of Law Enforcement (USFWS-OLE) (2004b): 16 USC 668-668d - Bald and Golden Eagle Protection Act. Version of 2004-MAR-30. Retrieved on 2008-FEB-14.
* United States Fish and Wildlife Service Office of Law Enforcement (USFWS-OLE) (2004b): National Eagle Repository. Version of 2004-OCT-20. Retrieved on 2007-NOV-20.
* United States Fish and Wildlife Service Southeast Region (USFWS-SR) (2001): Migratory Bird Feathers.