Golden eagles are North America's largest predatory bird. They are dark brown raptors with long, broad wings. Their length ranges from 70 to 84 cm, and their wingspan ranges from 185 to 220 cm. Males and females look similar, but females are much larger than males. Females weigh from 3940 to 6125 g. Males weigh from 3000 to 4475 g. Adults are mostly dark brown. They have a grayish brown tail and golden brown on their heads. Adults have dark brown eyes. Their bills and claws are black and their ceres and feet are yellow. Their legs are covered in feathers all the way down to the toes.
Juvenile golden eagles look similar to adults, but they have light patches on the tips of their wings, and a wide white band on their tails. They begin to look like adults when they are 4 to 6 years old.
There are 5 or 6 subspecies of the golden eagle. Only one subspecies, Aquila chrysaetos canadensis is found in North America. (Kochert, et al., 2002)
Golden eagles (Aquila chrysaetos) have a Holarctic distribution. They occur throughout Eurasia, in northern Africa, and in North America. In North America, golden eagles are found in the western half of the continent, from Alaska to central Mexico, with small numbers in eastern Canada and scattered pairs in the eastern United States. (Kochert, et al., 2002)
Golden eagles live in open and semi-open habitats from sea level to 3600 m elevation. They can be found in habitats such as tundra, shrublands, grasslands, woodland-brushlands, and coniferous forests. Most golden eagles are found in mountainous areas, but they also nest in wetland, riparian and estuarine habitats. (Kochert, et al., 2002)
Golden eagles are monogamous, and pairs may breed together for several years. In sedentary populations, pairs stay together year round. Golden eagle courtship includes the pair flying together, chasing, diving and pretending to attach each other. (Kochert, et al., 2002)
Golden eagles breed between March and August. Some golden eagles are sedentary, remaining in the same territory all year. These eagles may begin building their nests and forming pairs as early as December. Migratory golden eagles don’t begin pair formation and courtship until they return to the breeding grounds in early spring. Many pairs re-use the same nest for many years. Golden eagles usually build their nests on cliffs, but may also use trees, riverbanks and man-made structures, such as windmills, observation towers, nest platforms, and electrical towers. Nests are built 0 to 107 m off the ground. The male and female both build the nest. This takes 4 to 6 weeks. Nests are made of sticks and lined with soft vegetation, such as grasses, dry yucca leaves, inner bark, dead and green leaves, mosses and lichens. Some golden eagle nests are huge. The largest nest was 6.1 m tall and 2.59 m wide.
The female lays 1 to 4 (usually 2) eggs. She lays one egg every 3 to 4 days. The female incubates the eggs for 35 to 45 days (average 42 days). The chicks hatch several days apart, and are helpless (altricial). The older nestlings are usually much larger than the younger nestlings, and the older, stronger eaglets often kill the smaller chicks. The female parent broods the chicks regularly for up the first 45 days or so. Both parents bring food to the nestlings. The nestlings begin to leave the nest when they are 45 to 81 days old. They first leave the nest by walking, hopping or falling out of it. They begin to fly when they are about 10 weeks old, and become independent from their parents 32 to 80 days after fledging. Golden eagles begin to breed when they are 4 to 7 years old. (Kochert, et al., 2002)
The female golden eagle of a pair does most of the incubation. She also broods the chicks much of the time for the first 45 days after hatching. Both parents bring food to the nest, but the male provides more food than the female. (Kochert, et al., 2002)
The oldest known golden eagle lived to 46 years in captivity. In the wild, golden eagles have been known to live up to 32 years. (Kochert, et al., 2002)
Some golden eagles are sedentary, and others are migratory. In North America, most golden eagles in Alaska and Canada migrate south in autumn. Most pairs that breed in the continental U.S. and southern Canada stay in the same area year-round.
Golden eagles are usually solitary or in pairs. However, young golden eagles may be found in groups. Adults may also group together in winter when the weather is very cold, or there is a lot of food available.
Golden eagles can carry up to 8 pounds while flying. They can fly up to 80 mph, and may reach 200 mph while diving. They fly with slow, powerful wingbeats. (Kochert, et al., 2002)
Golden eagle home range sizes vary with season and quality of habitat. During the breeding season, golden eagles in the western U.S. have home ranges from 20 to 33 square kilometers. Breeding pairs defend the boundaries of their home range with flight displays. (Kochert, et al., 2002)
Golden eagles are mostly silent, except during the breeding season. They use nine different calls to communicate. Most calls appear communicate about food. Golden eagles don't use vocalizations to mark their territory. Instead, they mark the edges of their territory by flying around them. (Kochert, et al., 2002)
Golden eagles mostly eat small mammals such as rabbits, hares, ground squirrels, prairie dogs, and marmots. They also eat some birds, reptiles and fish. Sometimes, golden eagles capture large prey, including seals (Phocoidea), ungulates, coyotes and badgers. They have also been known to capture large flying birds such as geese or cranes.
A pair of eagles will often hunt together. One chases the prey until it is exhausted, then the other swoops down to kill it. Golden eagles don’t usually store prey to eat later. (Kochert, et al., 2002)
Golden eagles have few predators. There is no record of predation of golden eagle eggs, and few records of adult or nestling predation. Wolverines and grizzly bears are the only recorded predators of golden eagle nestlings. (Kochert, et al., 2002)
Golden eagles impact the populations of the animals that they prey on. They may also compete with other species for prey and habitat, including bald eagles, coyotes, California condors, and white-tailed eagles. They also probably compete with other large birds for habitat. These other birds common ravens, gyrfalcons, peregrine falcons, rough-legged hawks and other species. (Kochert, et al., 2002)
Golden eagles occasionally kill livestock, costing ranchers money.
Some researchers suggest that golden eagles are beneficial to livestock production because they eat a large number of rabbits, which compete with livestock for forage.
The golden eagle is federally protected under the Bald Eagle Protection Act of 1962. In some parts, a decline of golden eagle populations has been recorded. Washington and Montana list it as a species of special concern; and Maine, New Hampshire and New York recognize it as an endangered species. But in other areas they are common and populations are presumably stable. (Tesky, 1994)
Previous to the Protection Act of 1962, some 20,000 golden eagles were killed, mostly from aircraft, because they were thought to prey on yound sheep and goats. But studies in towns where sheep are raised found no evidence to support such claims, as almost 70% of the eagle diet consisted of rabbits. Many golden eagles have been electrocuted in power lines, caught in steel traps set for coyotes and other animals, and poisoned by ranchers. Direct and indirect human-caused mortality, disturbance and elimination of prey by habitat alteration are the main factors limiting golden eagle populations. Recreational activites may also disturb breeding, migration and wintering activities. Golden eagles are likely to abandon nests during incubation if they are disturbed. (Terres, 1980; http://www.fs.fed.us/database/feis/animals/Bird)
Golden eagles are sometimes called the American War Bird or the Bird of Jupiter (Terres, 1980).
Kari Kirschbaum (author, editor), Animal Diversity Web.
Alicia Ivory (author), University of Michigan-Ann Arbor.
living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.
uses sound to communicate
living in landscapes dominated by human agriculture.
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
Referring to an animal that lives in trees; tree-climbing.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends.
an animal that mainly eats meat
mid-altitude coastal areas with mild, rainy winters and long, dry summers. Dominant plant types are dense, evergreen shrubs.
uses smells or other chemicals to communicate
ranking system or pecking order among members of a long-term social group, where dominance status affects access to resources or mates
animals that generate their own body heat through metabolic processes.
an area where a freshwater river meets the ocean and the fresh and saltwater mixes
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
Found in northern North America and northern Europe or Asia.
offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).
marshes are wetland areas often dominated by grasses and reeds.
makes seasonal movements between breeding and wintering grounds
Having one mate at a time.
having the capacity to move from one place to another.
This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
the area in which the animal is naturally found, the region in which it is endemic.
reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.
the regions of the earth that surround the north and south poles, from the north pole to 60 degrees north and from the south pole to 60 degrees south.
"many forms." A species is polymorphic if its individuals can be divided into two or more easily recognized groups, based on structure, color, or other similar characteristics. The term only applies when the distinct groups can be found in the same area; graded or clinal variation throughout the range of a species (e.g. a north-to-south decrease in size) is not polymorphism. Polymorphic characteristics may be inherited because the differences have a genetic basis, or they may be the result of environmental influences. We do not consider sexual differences (i.e. sexual dimorphism), seasonal changes (e.g. change in fur color), or age-related changes to be polymorphic. Polymorphism in a local population can be an adaptation to prevent density-dependent predation, where predators preferentially prey on the most common morph.
Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
living in residential areas on the outskirts of large cities or towns.
uses touch to communicate
this biome is characterized by large expanses of coniferous forest, there is an extended cold season and heavy snowfall.
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
A terrestrial biome found in very cold places -- either close to polar regions or high on mountains. Part of the soil stays frozen all year. Few kinds of plants grow here, and these are low mats or shrubs not trees. The growing season is short.
uses sight to communicate
Reilly, E. The Audubon Illustrated Handbook of American Birds. McGraw-Hill Book Company, New York, 1968.
Terres, John. The Audubon Society Encyclopedia of North American Birds. Alfred A. Knoph, New York, 1980.
"The Raptor Center, University of Minnesota College of Veterinary Medicine" (On-line). Accessed (Date Unknown) at http://www.raptor.cvm.umn.edu/.
Kochert, M., K. Steenhof, C. McIntyre, E. Craig. 2002. Golden Eagle (Aquila chrysaetos). Pp. 1-44 in A Poole, F Gill, eds. The Birds of North America, Vol. 684. Philadelphia: The Birds of North America.