The White-headed Eagle seldom utters its piercing cry without throwing its head backward until it nearly touches the feathers of the back. It then opens its bill, and its tongue is seen to move as it emits its notes, of which five or six are delivered in rapid succession. Although loud and disagreeable when heard at hand, they have a kind of melancholy softness when listened to at a great distance. When these birds are irritated, and on the wing, they often thrust forth their talons, opening and closing them, as if threatening to tear the object of their anger in pieces.
The synonyms and necessary references having been already given in the first volume ([page 169]), it is unnecessary to repeat them here. Wilson figured and described the young of the White-headed Eagle under the name of the Sea Eagle, Falco ossifragus, although not without expressing doubts.
Falco leucocephalus, Ch. Bonaparte, Synops. of Birds of the United States, p. 26.—Nuttall, Manual, part i. p. 72.
Aquila leucocephala, Swains. and Richards. Fauna Boreali-Americana, part ii. p. 15.
Sea Eagle, Falco ossifragus, Wils. Amer. Ornith. vol. vii. p. 16. pl. 55. fig. 2.
The Young Bird fully fledged is represented in Plate CXXVI.
In this state it differs greatly in its colours from the F. ossifragus or young of the F. albicilla of Europe, with which it was confounded by Wilson.
The bill is black above, bluish-grey towards the end of the lower mandible, the cere, the base of the lower mandible, and the soft margins of the bill at the angle, yellow tinged with green. The narrow elongated feathers of the head and neck are dark-brown tipped with dull white, and the general colour of the plumage above is dull hair-brown; the lower parts having the feathers deep brown, broadly margined with greyish-white. The quills are deep brown, and the tail-feathers are brownish white, minutely mottled with dark brown, and having their extremities of that colour. The iris is yellowish-brown, the feet greenish-yellow, the claws black.
The Adult birds have been described in vol. i. of the present work, [p. 169].