The White-tailed Eagle, whose range includes northern Eurasia and Greenland, is a very rare visitor to North America. It resembles a Bald Eagle in plumage, size, and diet. The combined appearance of the head and tail is the most obvious difference in adult plumage between the two species. In the White-tailed Eagle, the tail is the only part of its body that is completely white compared to the all-white head and tail of the Bald Eagle. Immature and sub-adult plumages of the White-tailed Eagles are also similar to those of the Bald Eagle.
The White-tailed Eagle is about the same size as the Bald Eagle in Alaska, making it a large-sized raptor. It is also a superb fisherman, and an accomplished pirate, like the Bald Eagle.
Although quite rare, and in low numbers, the White-tailed Eagle occurs throughout the year in south-western Alaska. There are also several other accidental occurrences for northern parts of the continent.
SIZE
The White-tailed Eagle is a large bird of prey in which the female is larger than the male and averages about 20 percent heavier. Combined, their lengths vary from 27 to 36 inches (69 to 91 centimeters) and average about average 33 inches (84 centimeters). Wingspread measurements vary from 82 to 97 inches (208 to 247 centimeters) with an average of 91 inches (231 centimeters). The weight varies from 6.8 to 15.2 pounds (3.1 to 6.1 kilograms) with an average of 10.6 pounds (4.8 kilograms). The usual weight of a male is about 10 pounds (4.5 kilograms) and a female about 13 pounds (5.9 kilograms).
MORPHS
There are no light or dark color morphs although total albinism has been reported.
SPECIFIC DESCRIPTION
Adult - Perched
- head and neck appear pale, usually a light buffy-brown, or creamy buff in color
- head blends into brown breast and back without obvious contrast as in Bald Eagle
- yellow beak and cere
- eye appears pale or yellowish-white
- upperparts various shades of brown, sometimes grayish-brown, with pale edges to feathers
- underparts brown progressing to dark brown on the belly
- feathers under the tail are dark brown
- all-white tail
- legs yellow with dark brown feathers
Immature (First year) - Perched
- all dark brown head and eyes with black beak and cere
- feathers on upperparts are a mottled honey-colored brown, and patterned, and contrast with the all brown-black primary feathers
- breast is darker brown than belly but former has whitish to buffy streaks, latter shows darker streaks
- pale yellow legs with brown feathers
- longer tail than adult; usually dark (sometimes mottled) with flecks of white; from below tail appears lightish or whitish
- tip of tail appears to have white spikes
SIMILAR SPECIES
The White-tailed Eagle, within its range in Alaska, should only be confused with the Bald Eagle and Steller's Sea-Eagle. The adult Bald Eagle has a pure white head and short fan-shaped tail that is well defined and sharply separated from the dark body. The White-tailed Eagle has a light brown, tan, or creamy buff head and the tail is white but longer and wedge-shaped. Feathers under the tail are white in a Bald Eagle and dark in a White-tailed Eagle. The Steller's Sea-Eagle shows large white wing patches.
Immatures are easily confused as they resemble one another. The tail of immature Bald Eagles have an even and broad dark band near the tip while in the White-tailed Eagle the tail feathers appear spiked. Immature White-tailed Eagles have small whitish armpit areas and few white diagonal lines or white on the wing linings. Seven versus six "fingers" on outer primary feathers of the White-tailed Eagle separates it from a Bald Eagle. Also, the contrast of the breast to belly is less defined in immature White-tailed Eagles. Immature and subadult Steller's Sea-Eagles show mostly white, extremely wedge-shaped tails and very large yellow beaks.
OTHER NAMES
The White-tailed Eagle is also known as the "Cliff Eagle", "Sea-Eagle", "Shore Eagle", "White-tailed Sea Eagle", "Gray Sea Eagle", and "Erne" which is an Anglo-Saxon term meaning "the soarer". The latter name is a favorite selection for crossword puzzles!
ETYMOLOGY
The genus Haliaeetus stems from the Greek word halos meaning "sea", and aetos meaning "eagle". The specific name albicilla is from Latin word albus meaning "white" and illus, a diminutive suffix used mistakenly to mean "tailed". Translated, Haliaeetus albicilla is "White-tailed Sea Eagle."
MYTHOLOGY
None is known for North America.
VOICE
Near its nest the White-tailed Eagle utters a "ga" sound. A "kee" or "klee" is given when another White-tailed Eagle approaches the nest. During courtship the female utters a "kee" , "kee", ... series which ends in a "ka". Calls have also been described as a series of stuttering yelps that sound like "kyick, kyick, kyick..."