Golden Eagle
Adult of the North American subspecies
Conservation status
Least Concern (IUCN 3.1)
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Accipitriformes
Family:	Accipitridae
Genus:
Species:
Binomial name
(Linnaeus, 1758)
Light green = Breeding only Blue = Wintering only Dark green = All-year
Synonyms
Linnaeus, 1758

The Golden Eagle () is one of the best known birds of prey in the Northern Hemisphere. Like all eagles, it belongs to the family Accipitridae. Once widespread across the Holarctic, it has disappeared from many of the more heavily populated areas. Despite being extirpated from some its former range or uncommon, the species is still fairly ubiquitous, being present in Eurasia, North America, and parts of Africa. The highest density of nesting Golden Eagles in the world lies in southern Alameda County, California. These birds are dark brown, with lighter golden-brown plumage on their heads and necks.

Golden Eagles use their agility and speed combined with extremely powerful talons to snatch up prey including rabbits, marmots, ground squirrels, and large mammals such as foxes, wild and domestic cats, mountain goats, ibex, and young deer. They will also eat carrion if prey is scarce, as well as reptiles. Birds, including large species up to the size of swans and cranes as well as ravens and Greater Black-backed Gulls have all been recorded as prey. They have even been known to attack and kill fully grown roe deer. The Eurasian subspecies is used to hunt and kill wolves in many native communities, where their status is regarded with great mystic reverence.

Golden Eagles maintain territories that may be as large as 155 square kilometres (60 square miles). They are monogamous and may remain together for several years or possibly for life. Golden Eagles nest in high places including cliffs, trees, or human structures such as telephone poles. They build huge nests to which they may return for several breeding years. Females lay from one to four eggs, and both parents incubate them for 40 to 45 days. Typically, one or two young survive to fledge in about three months.

Description

Subadult, note white in tail and dark neck

The Golden Eagle is a large, dark brown raptor with broad wings. Its size is variable: it ranges from 70 to 85 centimetres (2 ft 4 in to 2 ft 9 in) in length, has a wingspan of 185 to 220 centimetres (6 ft 1 in to 7 ft 3 in), and weighs 3 to 6 kilograms (7 to 13 lb). Sexes are similar in plumage but are considerably dimorphic in size, with females much larger than males. Adults are primarily brown, with gold on the back of the crown and nape, and some grey on the wings and tail. tarsal feathers range from white to dark brown. In addition, some birds have white "epaulettes" on the upper part of each scapular feather tract. The bill is dark at the tip, fading to a lighter horn color, with a yellow cere.

Juveniles have a darker, unfaded color, white patches in the remiges which may be divided by darker feathers, and a large amount of white on the tail with a black terminal band. Occasionally upper wing feathers of juveniles are also white, or birds lack white on the wing entirely. As the bird ages, the amount of white on wings and tail diminishes, and adult plumages is usually acquired by the fifth year.

Taxonomy and systematics

This species was first described by Linnaeus in his 1758 as . The type locality was given simply as "Europa"; it was later fixed to Sweden. It was moved to the new genus by French ornithologist Mathurin Jacques Brisson in 1760.

The Golden Eagle is one of the largest eagles in the genus , which are distributed almost worldwide. The latest research indicates it forms a worldwide superspecies with Verreaux's Eagle, Gurney's Eagle, and the Wedge-tailed Eagle.

Subspecies and distribution

There are six extant subspecies of Golden Eagle that differ slightly in size and plumage.

• (Linnaeus, 1758) – The nominate subspecies. Eurasia except Iberian peninsula, east to western Siberia.
• (Linnaeus, 1758) – North America.
• Severtzov, 1888 – Eastern Siberia, from the Altay to the Kamchatka Peninsula. Often included in .
• Severtzov, 1888 – Southern Kazakhstan east to Manchuria and south-west China, along the Himalayas from northern Pakistan in the west to Bhutan in the east.
• Severtzov, 1888 – Iberian peninsula and North Africa, east to Turkey and Iran.
• Severtzov, 1888 – Japan and Korea.

The larger Middle Pleistocene Golden Eagles of France (and possibly elsewhere) are referred to a paleosubspecies , and the huge specimens of the Late Pleistocene of Liko Cave (Crete) have been named .

Ecology

Feeding

At San Francisco Zoo, USA. The beak is well-suited to tear apart large prey

The Golden Eagle's predominant prey in North America are leporids (hares and rabbits) and sciurids (ground squirrels, prairie dogs, and marmots). In a study, mammals comprised 83.9% of the eagles' diet. Its prey also varies by region: in Washington, the Yellow-bellied marmot was eaten significantly more than other species, while in Sweden, birds were primarily consumed, especially the Western Capercaillie.

Additional mammals regularly taken include mice, martens, foxes, young deer, and mountain goats.

The secondary important prey group for Golden Eagles are other birds. Various gallinaceous birds (largely phasianids, ptarmigans and grouse) are the most significant avian prey. However, virtually any bird, from a Eurasian Jay to a swan or a even a Common Crane, is potential prey. Golden Eagles are avian apex predators, meaning a healthy adult is not preyed upon. There are records of Golden Eagles killing and eating large raptors such as Gyrfalcons, Northern Goshawks, and Buteo hawks, whether adults, nestlings or eggs. Falcons, skuas, and like Rough-legged Hawks, which are normally competitors, have worked together to group-mob Golden Eagles that have passed their adjacent nesting areas. In one instance, a Golden Eagle flying in towards a Peregrine Falcon nest was struck and killed by a swooping parent falcon. This may have been a freak event since, bearing in mind the eagle is many times larger and more powerful than the falcon, the reverse outcome is much more likely. More commonly, Golden Eagles kleptoparasitize, or steal prey, from other raptors. While not as large as some vultures, Golden Eagles are capable of driving vultures and other raptors from carrion.

During winter months when prey is scarce, Golden Eagles scavenge on carrion or large prey, such as goat-antelopes and caribou. There is one confirmed report of a Golden Eagle snatching the cub of a Brown Bear,

Reproduction

Eyrie (in hollow at left center) in the Valley of the Siagne de la Pare, Alpes-Maritimes, France

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. Their predators are just the right size for Golden Eagle prey, and therefore avoid active eyries.

The female lays one to four (usually two) eggs between January and September (depending on the locality). The eggs vary from all white to white with cinnamon or brown spots and blotches. They start incubation immediately after the first egg is laid, and after 40 to 45 days the young hatch. They are covered in fluffy white down 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. This strategy is useful for the species because it makes the parents' workload manageable even when food is scarce, while providing a reserve chick in case the first-born dies soon after hatching. Golden Eagles invest much time and effort in bringing up their young; once able to hunt on their own, most Golden Eagles survive many years, but mortality even among first-born nestlings is much higher, in particular in the first weeks after hatching.

Status and conservation

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, but in former centuries it also bred in the plains and the forests. In recent years it has started to breed in lowland areas again, e.g., in Sweden and Denmark.

There was a great decline in Central Europe where they are now essentially restricted to the Apennine, Alps, and Carpathian Mountains. In Britain, the last comprehensive survey of Golden Eagles took place in 2003, and found 442 occupied territories. A less thorough survey in 2007 showed that in addition to large numbers of territories in the Scottish Highlands and the Inner and Outer Hebrides, there were a handful of birds in southern Scotland and northern England. Between 1969 and 2003 they nested in the Lake District, Cumbria.

In Ireland, where it had been extinct due to hunting since 1912, efforts are being made to re-introduce the species. Forty-six birds were released into the wild in Glenveagh National Park, County Donegal, from 2001 to 2006, with at least three known female fatalities since then. It is intended to release a total of sixty birds, to ensure a viable population. In April 2007, a pair of Golden Eagles produced the first chick to be hatched in the Republic of Ireland in nearly a century. The previous attempt to help the birds breed at the Glenveagh National Park had failed.

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. In the 20th century, organochloride and heavy metal poisonings were also commonplace, but these have declined thanks to tighter regulations on pollution. Within the United States, the Golden Eagle is legally protected by the Bald and Golden Eagle Protection Act.

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.

In human culture

1870s illustration of falconers in Kazakhstan

Falconry

Golden Eagles have been used in falconry since the Middle Ages. In Asia, they were used in teams to hunt such animals as deer, antelope and wolves, while their use was reserved for Emperors in Europe. They can be trained for falconry.

Heraldry

Mexican coat of arms

Coat of arms of Egypt

The Golden Eagle is the national bird of five nations, Albania, Germany, and Austria in continuation of the Holy Roman Empire,, Mexico and Kazakhstan, the most of any species. The eagle is very much connected to the Saladin Golden Eagle, currently used as the coat of arms of Egypt, Iraq, and Palestine, it was also previously used by Libya, and Yemen.

The Golden Eagle was model for the , the standard of the Roman legions. It is featured in the national coats of arms of Germany, Albania, Austria, Egypt, Mexico, Romania and many other countries.

Religion

In North America

The eagle is a sacred bird in some cultures and the feathers of the eagle are central to many religious and spiritual customs, especially among some Native Americans in the United States and First Nations in Canada, as well as among many of the peoples of Meso-America. Some Native American peoples revere eagles as sacred and the feathers and other parts of Bald and Golden Eagles. Feathers are often worn on Native American headdresses and have been compared to the Bible and crucifix of Christianity. Eagle feathers are often used in various Native ceremonies and are used to honour noteworthy achievements and qualities such as exceptional leadership and bravery. The Golden Eagle is thought to be the origin of the Thunderbird legends of the southwestern United States,

Current United States eagle feather law (50 CFR 22) stipulates that only individuals of certifiable Native American ancestry enrolled in a federally recognized tribe are legally authorized to obtain eagle feathers for religious or spiritual use. Thus, the supply of eagle material for traditional ceremonial use can be guaranteed and ceremonial eagle items can be passed on as heirlooms by their traditional owners without the restrictions that would usually apply. Commercial trade in Golden Eagles or their feathers or body parts is not legalized by these exceptions.

Postage stamps

The Golden Eagle is the eighth-most common bird depicted on postage stamps with 155 stamps issued by 71 stamp-issuing entities.

Other

J.R.R. Tolkien used an image of an immature Golden Eagle from T. A. Coward's 1919 work for an illustration depicting Bilbo awaking next to Gwaihir.

Works cited

• Clark, William S.; Wheeler, Brian K. (2001). . New York: Houghton Mifflin Company. ISBN 0395670675. http://books.google.com/?id=a_pbxM21l5UC&printsec=frontcover#v=onepage&q&f=false. Retrieved 26 December 2010. 
• Cramp, Stanley, ed (1979). . Oxford: Oxford University Press. ISBN 978-0198575054. 
• Terres, John K. (1980). "Golden Eagle". . New York: Alfred A. Knopf. ISBN 0517032880.