A
cockatoo is any of the 21 bird species
belonging to the family Cacatuidae. Along
with the Psittacidae family (the true
parrots), they make up the order Psittaciformes.
The name cockatoo originated from the
Malay name for the bird, kakaktua, which
translates literally as older sister (from
kakak, "sister," and tua, "old").
Cockatoos share many features with other
parrots including the characteristic curved
beak shape and a zygodactyl foot, with
two forward toes and two backwards toes.
They differ, however in a number of characteristics,
including the often spectacular movable
headcrest, and their lack of the Dyck
texture feather composition, which gives
feathers of many parrots their iridescence.
Cockatoo species are also, on average,
larger than the true parrots (however,
the cockatiel is a small cockatoo and
the very large parrots include the Hyacinth
Macaw by length and the Kakapo by weight.)
Cockatoos
have a much more restricted range than
the true parrots, occurring naturally
only in Australia and nearby islands.
Eleven of the 21 species exist in the
wild only in Australia, while seven species
occur in Indonesia, New Guinea, and other
south Pacific islands. Three species occur
in both New Guinea and Australia. All
of the species of cockatoo are protected
by the CITES international agreement which
make the trade of wild-caught specimins
of endangered or vulnerable species illegal.
Phylogeny of the family Cacatuidae based
on existing molecular evidence.The list
below is a traditional classification
of the cockatoos. However, Brown &
Toft (1999) performed molecular analysis
on 15 out of the 18 recognised species
in this group. The Cockatiel and the Gang-gang
Cockatoo group together with the black
cockatoos of the genus Calyptorhynchus
as a clade, indicating that they should
move to the subfamily Calyptorhynchinae,
and the subfamily Nymphicinae should deprecated.
Major Mitchell's Cockatoo is basal to
all other Cacatua species, indicating
that its original placement in the monotypic
genus Lophocroa is valid.
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