Size The golden eagle is a very large raptor, in length. Its wings are broad and the wingspan is . The wingspan of golden eagles is the fifth largest among living eagle species. The maximum size of golden eagles is debated. Large subspecies are the heaviest representatives of the genus
Aquila and this species is on average the seventh-heaviest living eagle species. The golden eagle is the second heaviest breeding eagle in North America, Europe and Africa and the fourth heaviest in Asia. American golden eagles are typically somewhat smaller than the large Eurasian species, but a massive female that was banded and released in 2006 around Wyoming's
Bridger-Teton National Forest became the heaviest wild golden eagle on record, at . Captive birds have been measured with a wingspan of and a mass of , though this mass was for an eagle bred for
falconry, which tend to be unnaturally heavy. The long, straight and powerful
hallux-claw (hind claw) can range from , about one centimetre longer than in a
bald eagle and a little more than one centimetre less than a
harpy eagle.
Colour Adults of both sexes have similar plumage and are primarily dark brown, with some grey on the inner wing and tail, and a paler, typically golden colour on the back of the crown and nape that gives the species its common name. The bill is dark at the tip, fading to a lighter horn colour, with a yellow
cere. As in many
accipitrids, the bare portion of the feet is yellow. Rarely, juvenile birds may have only traces of white on the tail. Compared to the relatively consistently white tail, the white patches on the wing are extremely variable; some juveniles have almost no white visible. Juveniles of less than 12 months of age tend to have the most white in their plumage. Many golden eagles still have white on the tail during their first attempt at nesting. The final adult plumage is not fully attained until the birds are between and years old. That being said, some vocalization has been recorded, usually centering around the nesting period. The voice of the golden eagle is considered weak, high, and shrill, has been called "quite pathetic" and "puppy-like", and seems incongruous with the formidable size and nature of the species. A typical, unhurried soaring speed in golden eagles is around . When hunting or displaying, the golden eagle can glide very fast, reaching speeds of up to . This makes the golden eagle one of the two fastest living animals.
Distinguishing from other species Size readily distinguishes this species from most other raptors when it is seen well. Most other raptors are considerably smaller.
Buteo hawks, which are perhaps most similar to the golden eagle in structure among the species outside of the "booted eagle" group, are often counted among the larger very common raptors. However, a mid-sized
Buteo is dwarfed by a golden eagle, as an adult female eagle has about double the wingspan and about five times the weight.
Buteos are also usually distinctly paler below, although some species occur in dark morphs which can be darker than a golden eagle. Among raptorial birds that share the golden eagle's range, only some
Old World vultures and the
California condor are distinctly larger, with longer, broader wings, typically held more evenly in a slower, less forceful flight; they often have dramatically different colour patterns. In North America, the golden eagle may be confused with the
turkey vulture from a great distance, as it is a large species that, like the golden eagle, often flies with a pronounced dihedral. The turkey vulture can be distinguished by its less controlled, forceful flying style (they frequently rock back and forth unsteadily in even moderate winds) and its smaller, thinner body, much smaller head and, at closer range, its slaty black-brown colour and silvery wing secondaries. Compared to
Haliaeetus eagles, the golden eagle has wings that are only somewhat more slender but are more
hawk-like and lack the flat, plank-like wing positioning seen in the other genus. Large northern
Haliaeetus species usually have a larger bill and larger head which protrudes more distinctly than a golden eagle's in flight. The tail of the golden eagle is longer on average than those of
Haliaeetus eagles, appearing to be two or three times the length of the head in soaring flight, whereas in the other eagles the head is often more than twice the length of the tail. Confusion is most likely between juvenile
Haliaeetus and golden eagles, as the adult golden has a more solidly golden-brown coloration and all
Haliaeetus eagles have obvious distinctive plumages as adults.
Haliaeetus eagles are often heavily streaked in their juvenile phase. Juvenile golden eagles can have large patches of white on their wings and tail that are quite different from the random, sometimes large and splotchy-looking distribution of white typical of juvenile
Haliaeetus. Distinguishing the golden eagle from other
Aquila eagles in Eurasia is more difficult. Identification may rely on the golden eagle's relatively long tail and patterns of white or grey on the wings and tail. Unlike golden eagles, other
Aquila eagles do not generally fly in a pronounced dihedral. At close range, the golden to rufous nape-shawl of the golden eagle is distinctive from other
Aquila. Most other
Aquila eagles have darker plumage, although the smaller
tawny eagle is often paler than the golden eagle (the overlap in range is verified only in
Bale Mountains,
Ethiopia). Among Eurasian
Aquila, the adult
eastern imperial and
Spanish imperial eagle come closest to reaching the size of golden eagles, but both are distinguished by their longer necks, flatter wings in flight, white markings on their shoulder forewing-coverts, paler cream-straw coloured nape patch and generally darker colouration. Juvenile imperial eagles are much paler overall (caramel-cream in the Spanish; cream and tawny streaks in the eastern) and are not likely to be confused.
Steppe eagles can also approach golden eagles in size but are more compact and smaller headed with little colour variation to their dark earth-brown plumage, apart from juvenile birds which have distinctive cream-coloured bands running through their coverts and secondaries.
Verreaux's eagles are most similar in size and body shape to the golden, the body of the Verreaux's eagle being slightly longer overall but marginally less heavy and long-winged than the golden eagle's. The plumage is very distinctly different, however, as Verreaux's eagles are almost entirely jet-black except for some striking, contrasting white on the wing primaries, shoulders and upper-wing. This closely related species is known to co-occur with the golden eagle only in the
Bale Mountains of
Ethiopia. Other booted eagles in the golden eagle's range are unlikely to be confused due to differences in size and form. The only species in the genus
Aquila that exceeds the golden eagle in average wingspan and length is the
wedge-tailed eagle of
Australasia; however, the wedge-tailed eagle is a slightly less heavy bird. == Habitat and distribution ==