Cockatoos

A cockatoo is any of the 21 species belonging to the bird family Cacatuidae. Along with the Psittacidae (the true parrots) and the Strigopidae (the large New Zealand parrots), they make up the parrot order Psittaciformes. Placement of the cockatoos as a separate family is fairly undisputed, although many aspects of the other living lineages of parrots are unresolved. The family has a mainly Australasian distribution, ranging from the Philippines and the eastern Indonesian islands of Wallacea to New Guinea, the Solomon Islands and Australia. The name cockatoo originated from the Malay name for these birds, kaka(k)tua (either from kaka "parrot" + tuwah, or "older sister" from kakak "sister" + tua "old").

Cockatoos are instantly recognisable by their showy crests and curved bills. On average they are larger than other parrots; however, the Cockatiel, the smallest cockatoo species, is a small bird. Their plumage is generally less colourful than that of other parrots, being mainly white, grey, or black, and often with coloured features in the crest, cheeks, or tail. The genus Cacatua comprises 11 species of white plumaged cockatoos, including the corellas, a group of smaller cockatoos. Closely related to them are the pink and grey Galah and the pink and white Major Mitchell's Cockatoo. The five species of the genus Calyptorhynchus are large black coloured cockatoos. The remaining three species—the large black-plumaged Palm Cockatoo, the mainly grey Gang-gang Cockatoo, and the small mainly grey Cockatiel—are related to the other cockatoos through early and unclear evolutionary branches.

The diet of the cockatoos is composed of seeds, tubers, corms, fruit, flowers and insects. They often feed in large flocks, particularly when ground-feeding. Cockatoos are monogamous and nest in tree hollows. Some cockatoo species have been adversely affected by habitat loss, particularly the loss of suitable nesting hollows when large, mature trees are cleared; conversely, some species have adapted well to human changes and are considered agricultural pests.

Cockatoos are popular birds in aviculture, but their needs are difficult to cater for. However, the Cockatiel is much easier to keep as a pet, and is by far the most popular. White cockatoos are more commonly found in captivity than black cockatoos. Some species are threatened by the largely illegal trade in wild-caught parrots.