Golden eagles are very large raptors. Their overall length may approach 3 feet with wingspans of approximately 7 feet. Females are generally larger than males. Females weigh around 13 pounds and males around 9 pounds. They are generally dark brown in color, but may have small patches of white or grey. Juvenile birds have a wide, white band at the base of their tail, and a dark brown bottom half. Full adult plumage is usually acquired by the time the bird is five years old. Golden eagles are frequently observed soaring or gliding.
Range: Golden eagles are very widely distributed, occurring world-wide throughout the Northern Hemisphere. In North America they occur primarily from Alaska and western Canada, south through the western United States and northern Mexico. They are migratory from central Canada and areas further north, but are resident throughout the rest of their North American range.
Habitat: Golden eagles use a very wide range of habitats. For nesting they most frequently use cliffs but will also nest in trees. Because of their large size and predatory nature, they require large areas of foraging habitat. Tundra, high- and mid-elevation pine forest, piñon-juniper woodlands, sagebrush and other shrub habitats, grassland, and agricultural habitats are all used by golden eagles. In Colorado, golden eagles breed primarily in montane habitats in the west and canyon habitats in the southeast. There is some limited breeding in northeast Colorado. In winter, golden eagles range more widely and occur commonly throughout Colorado.
Diet: Golden eagles forage primarily on a wide variety of small- and medium-sized mammals, including rabbits, hares, prairie dogs, ground squirrels, and marmots. They have occasionally been observed killing pronghorn antelope and deer. When available, golden eagles will readily feed on carrion.
Reproduction: Golden eagles form strong pair bonds, frequently remaining with the same mate for several years. Some individuals are assumed to mate for life. They frequently reuse nests from previous years, adding material to the nest throughout the year. Nests are large, often as large as 6 ft. by 4 ft. in diameter. In Colorado, courtship may begin as early as March with young being hatched as early as mid-April. However, some pairs will nest later, with young still at nests in mid-July. Clutch size is usually 1-3 eggs. Usually only one chick survives to fledging, as the chick which hatches first typically kills the younger one (known as the “Cain-Abel Syndrome” or siblicide). Females perform nearly all incubation and brooding. Both sexes bring prey to the young. Fledging usually occurs around 65 days after hatching.