Illegal trade in wild-caught birds contributes to the decline of some cockatoo species in the wild. White cockatoos are more commonly found in captivity than black cockatoos. The cockatiel is the easiest cockatoo species to maintain and is by far the most frequently kept in captivity. Some cockatoo species have been adversely affected by habitat loss, particularly from a shortage of suitable nesting hollows after large mature trees are cleared conversely, some species have adapted well to human changes and are considered agricultural pests.Ĭockatoos are popular birds in aviculture, but their needs are difficult to meet. Cockatoos are monogamous and nest in tree hollows. They often feed in large flocks, particularly when ground-feeding. The second and larger branch is formed by the genus Cacatua, comprising 11 species of white-plumaged cockatoos and four monotypic genera that branched off earlier namely the pink and white Major Mitchell's cockatoo, the pink and grey galah, the mainly grey gang-gang cockatoo and the large black-plumaged palm cockatoo.Ĭockatoos prefer to eat seeds, tubers, corms, fruit, flowers and insects. The five large black coloured cockatoos of the genus Calyptorhynchus form one branch. The remaining species are in two main clades. The phylogenetic position of the cockatiel remains unresolved, other than that it is one of the earliest offshoots of the cockatoo lineage. 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 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.Ĭockatoos are recognisable by the prominent crests and curved bills. Along with the Psittacoidea ( true parrots) and the Strigopoidea (large New Zealand parrots), they make up the order Psittaciformes. As such, crest feathers are widely studied in morphological research and other related biological disciplines, particularly concerning domesticated species.A cockatoo is any of the 21 parrot species belonging to the family Cacatuidae, the only family in the superfamily Cacatuoidea. The underlying molecular and genetic mechanisms that are responsible for crest feather formation in domesticated bird species are not well understood. Crest feathers in domestic birds include a wide range of variations in form across species.
These structures are known to have two origins: selective breeding or mutations. Many domesticated bird species have crest feathers. Some birds, like the galah, or rose-breasted cockatoo, have modified crests, which has features of both recumbent and recursive types. The sulphur-crested cockatoo has a recursive crest, and the Major Mitchell's cockatoo (also known as the Leadbeater's cockatoo) possesses a prominent recursive crest. Many recursive crests also feature brilliant colors. The recursive crest is noticeable even when it is not fanned out because it features feathers, that, when lying down, curve upward at the tips, and when standing up, often bend slightly forward toward the front of the head. The white cockatoo, for example, possesses a recumbent crest. The recumbent crest has feathers that are straight and lie down essentially flat on the head until the bird fans them out to where they stand up. Crests can be recumbent or recursive, depending on the species. Their crests are used to communicate with fellow members of their species, or as a form of defense to frighten away other species that approach too closely, making the bird appear larger when the crest is suddenly and unexpectedly raised. Cockatoos and cockatiels possess crests which may be raised or lowered at will. Cockatoos and their smaller cousins, cockatiels, are part of the parrot family Cacatuidae found in Australia, the Bismarck Archipelago and the Philippines, and are probably the most recognizable birds to feature crests. In birds, these semiplumes are common along the head, neck, and upper back, and may be used for buoyancy and sensing vibrations.Ĭrests on birds are generally used for display purposes. These are plumulaceous feathers, meaning that they are soft and bendable. The crest is made up of semiplume feathers: a long rachis with barbs on either side. It is distinct from features such as casques and cockscombs - sometimes erroneously referred to as "crests", which are bony and fleshy structures respectively.
The crest is a prominent feature exhibited by several bird and other dinosaur species on their heads. A restoration of the dinosaur Anchiornis, showing the crest of feathers on its head
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