COCKATOO (Cacatuidae)  , a family of parrots characterized among Old World forms by their usually greater size, by the crest of feathers on the head, which can be raised or depressed at will, and by the absence of green in their coloration . They inhabit the Indian Archipelago, New Guinea and Australia, and are gregarious, frequenting woods and feeding on seeds, fruits and the larvae of insects . Their note is generally harsh and unmusical, and although they are readily tamed when taken young, becoming familiar, and in some species showing remarkable intelligence, their powers of vocal imitation are usually limited . Of the true cockatoos (Cacatua) the best known is the sulphur-crested cockatoo (Cacatua galerita), of a pure white plumage with the exception of the crest, which is deep sulphur yellow, and of the ear and tail coverts, which are slightly tinged with yellow . The crest when erect stands 5 in. high . These birds are found in Australia in flocks varying from loo to r000 in number, and do great damage to newly-sown grain, for which reason they are mercilessly destroyed by farmers . They deposit their eggs—two in number, and of a pure white colour—in the hollows of decayed trees or in the fissures of rocks, according to the nature of the locality in which they reside . This is one of the species most usually kept in Europe as a cage bird . Leadbeater's Cockatoo (Cacatua Leadbeateri), an inhabitant of South Australia, excels all others in the beauty of its plumage, which consists in great part of white, tinged with rose colour, becoming a deep salmon colour under the wings, while the crest is bright crimson at the base, with a yellow spot in the centre and white at the tip . It is exceedingly shy and difficult of approach, and its note is more plaintive while less harsh"than that of the preceding species . In the cockatoos belonging to the genus Calyptorhynchus the general plumage is black or dark brown, usually with a large spot or band of red or yellow on the tail . The largest of these is known as the funereal cockatoo (Calyptorhynchus funerals), from the lugubrious note or call which it utters, resembling the two syllables Wy—la,—, the native name of the species .

It deposits its eggs in the hollows of the large

gum-trees of Australia, and feeds largely on the larvae of insects, in search of which it peels off the bark of trees, and when thus employed it may be approached closely . The cockateel (Calopsittacus novaehollandiae), the only species in the family smaller than a pigeon, and with a long pointed tail, is a common aviary bird, and breeds freely in captivity .