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Cockatoo

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iCockatoos
Image:Buberel White parrot.jpg
Moluccan Cockatoo (Cacatua (Cacatua) moluccensis)
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Psittaciformes
Family: Cacatuidae
GR Gray, 1840
Subfamily

Microglossinae
Calyptorhynchinae
Cacatuinae

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 these birds, 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, the presence of a gall bladder and some other anatomical details, and their lack of the Dyck texture feather composition which causes the bright blues and greens seen in true parrots. 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.

Contents

[edit] Cockatoos as endangered or vulnerable species

All of the species of cockatoo are protected by the CITES international agreement, which makes the trade of wild-caught specimens of endangered or vulnerable species illegal.

The following cockatoo species are classified as endangered species (on CITES appendix 1 list).

All of the other cockatoo species are classified at vulnerable (on CITES appendex 2 list).

[edit] Systematics and evolution

Image:Cockatoos.jpg
Phylogeny of the family Cacatuidae based on Brown & Toft (1999)

Brown & Toft (1999) reviewed the existing evidence and additional mitochondrial 12S rRNA sequence data to arrive at a well-supported phylogeny of the cockatoos. They could distinguish 3 subfamilies:

  1. The all-black Palm Cockatoo represents distinct lineage that diverged early; it was previousöly sometimes grouped with the other black species but this is incorrect.
  2. The dark cockatoos; sexually dichromatic species which have ample melanin in their plumage and some red, yellow or orange on wing, tail and face, barred feathers on wing, tail and/or body as well as contrasting ear area spotting in females, while males have the corresponding feathers unbarred and may lack the ear spotting. This group includes the remaining black cockatoos, the Gang-gang Cockatoo and, interestingly, the cockatiel which had previously been placed in a subfamily of its own (Nymphicinae) or even as a broad-tailed parrot.
  3. The remaining species, which are all hypomelanistic and not sexually dimorphic.

The genera Calyptorhynchus and Cacatua can be further resolved into two subgenera each, and in the latter case as a distinct third lineage the white-and-pink Major Mitchell's Cockatoo, which is intermediate in coloration between the grey-and-pink Galah and the white Cacatua. It is best recognized as a monotypic genus Lophocroa. Indeed, pending further research, all subgenera could conceivably be raised to species rank.

Intron 7 of nuclear β-fibrinogen sequence data suggests that the Microglossinae may have diverged later, and that the cockatiel might be distinct enough to warrant recognition of the Nymphicinae (Astuti, 2004?), but in other aspects agrees with the rRNA and newly-interpreted morphological data.

The fossil record of cockatoos is even more limited than that of parrots in general, with only one truly ancient cockatoo fossil known: A species of Cacatua, most probably subgenus Licmetis, was found in Early Miocene (16-23 mya) deposits of Riversleigh, Australia (Boles, 1993). In Melanesia, subfossil bones of Cacatua species which apparently did not survive early human settlement were found on New Caledonia and New Ireland[citation needed]. The bearing of these fossils on cockatoo evolution and phylogeny is fairly limited, ecxept that the Riversleigh fossil allows some tentative dating of the divergence of subfamilies.

FAMILY CACATUIDAE

[edit] References

  • Astuti, Dwi (2004?): A phylogeny of cockatoos (Aves: Psittaciformes) inferred from DNA sequences of the seventh intron of nuclear β-fibrinogen gene. Doctoral work, Graduate School of Environmental Earth Science, Hokkaido University, Japan. PDF fulltext
  • Boles, W.E. (1993): A new cockatoo (Psittaciformes: Cacatuidae) from the Tertiary of Riversleigh, northwestern Queensland, and an evaluation of rostral characters in the systematics of parrots. Ibis 135: 8-18.
  • Brown, D.M. & Toft, C.A. (1999): Molecular systematics and biogeography of the cockatoos (Psittaciformes: Cacatuidae). Auk 116(1): 141-157.

[edit] External links

da:Kakadue de:Kakadus es:Cacatuidae eo:Kakatuedoj fr:Cacatuinae io:Kakatuo it:Cacatuidae he:קקדואיים ka:კაკადუ nl:Kaketoes no:Kakaduer pl:Kakadu pt:Cacatua ru:Какаду sv:Kakaduor tr:Kakadu zh:凤头鹦鹉科

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