Cockatoo

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Cockatoos
Umbrella Cockatoo
Scientific classification
Kingdom:
Phylum:
Class:
Order:
Family:
Cacatuidae

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Subfamily

Microglossinae
Calyptorhynchinae
Cacatuinae

A cockatoo is any of the 20 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, kaka(k)tua (either from kaka "parrot" + tuwah, or "older sister" from kakak "sister" + tua, "old"[verification needed]).

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. Also Cockatoo species are, on average, larger than the average size of true parrots; however, the cockatiel, the smallest Cockatoo, is a small bird, and some of the largest parrots including the Hyacinth Macaw (the longest parrot) and the flightless Kakapo (the heaviest parrot), are true parrots. Placement of the cockatoos as a separate family is fairly undisputed, but it is not resolved whether or not other living lineages of parrots (such as the lories and lorikeets) are as distinct as they are.

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.

A flock of Sulphur-crested Cockatoos eating from an Almond tree in Australia

Cockatoos as endangered or vulnerable species

All species of cockatoo are protected by the Convention on International Trade in Endangered Species of Wild Fauna and Flora (also known as CITES), which makes the import, export and trade in all wild-caught parrots and cockatoos illegal.

The following cockatoo species are protected on the CITES appendix 1 list of endangered species.

All of the other cockatoo species are protected on the CITES appendix 2 list of vulnerable species. However, some species of Australian cockatoos including corellas and galahs, have large populations and are sometimes killed as crop pests.

Systematics and evolution

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 previously 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 genus 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, except that the Riversleigh fossil allows some tentative dating of the divergence of subfamilies.

File:DSC 2444 bis.jpg
A sulphur-crested cockatoo

Family Cacatuidae

A yellow tailed Black Cockatoo

Aviculture

Cockatoos are very popular as pets in part to their striking beauty but also for their intelligence and usually affectionate, outgoing, cuddly, and gentle personalities. Despite their high cost which typically ranges from $500-$2000, cockatoos can make a great pet for the right owners. Actual cost of the bird is not the only cost to consider. Remember when buying a bird you must purchase a large birdcage, which must be big enough for your cockatoo to be active. Feeding your Cockatoo is also a consideration as they require a balanced diet of good quality pellet food in addition to fresh fruits and vegetables. Complementing the diet with seeds and nuts can also be great for your Cockatoo. Cockatoos can be quite destructive and require a regular supply of branches and toys for chewing.

Cockatoos are also not without their problems. In fact there are some who believe that no one should keep one of these birds as a house pet because of the challenges ownership can present. Cockatoos have been called the 'velcro' bird Cockatoos because they typically love to cuddle and spend time with their owner. However, cockatoos are extremely loud birds and some owners may inadvertently teach them to scream for attention. A cockatoo should be rewarded when it is quiet and ignored when it screams excessively to avoid this problem. Cockatoos should also be provided with a variety of interesting toys and encouraged to play by themselves from a young age to avoid them becoming overdependant on constant attention from the owners, which can be the cause of behavioral problems later on. Feather plucking is a problem some cockatoo owners may experience. It may be caused by several different factors, including boredom, lack of appropriate chewable toys, health problems, or allergies, and it's not always easy to determine what they are or how to fix them. Some otherwise sweet adolescent male (and occasionally female) cockatoos may show aggression during the breeding season; cockatoos are capable of very damaging bites. Cockatoos are also very intelligent and mischief prone, and many become adept at escaping locked cages and may chew on furniture and woodwork in the house. Some owners recommend building an outdoor aviary into which a pet cockatoo may be put for a few hours a day in good weather; an aviary provides an excellent outlet for a cockatoo's energy that might otherwise be spent on undesirable behaviors. A cockatoo can make a challenging pet and has a long lifespan of up to 40-70 years depending upon species, so they require an owner committed to their care.

In general, the smaller cockatoo species are considered to be easier to keep as pets than large cockatoos such as Moluccans.

Cockatiels In contrast to the other cockatoos, the cockatiel is relatively quiet, non-destructive, less demanding, inexpensive, and gentle natured, though a pet cockatiel still requires daily attention and handling from its owners and veterinary care. Cockatiels are popular as pets, and among the species most often recommended to new bird owners. Cockatiels have a typical maximom lifespan of 20 years but some have lived to over 30.

Cockatoos are popular for use in trained bird shows. Many owners find they can be taught many tricks and husbandry behaviors, though cockatoos are generally less food motivated than other birds; some birds may be more motivated by a reward of petting or praise than of food. Cockatoos can often be trained to accept a parrot harness, enabling their owners to take them outdoors. Cockatoos have been used in animal-assisted therapy, generally in nursing homes.

Popular culture

Cockatoos often have pronounced responses to musical sounds, and numerous videos exist showing the birds "dancing" to popular music, although it is not known if their musical perception is any different from that of other birds. A search with the terms "dancing cockatoo" yields over 200 results on YouTube, mostly by private owners.

Slang

In Australian slang or vernacular speech a person who is deputed to keep a look-out whilst colleagues undertake clandestine or illegal activities particularly such as organising illegal gambling may be referred to as a "cockatoo". Proprietors of small agricultural undertakings are frequently jocularly or slightly disparagingly referred to as a "cocky". [1]

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.

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