Red-tailed Black Cockatoo (Calyptorhynchus banksii) - Wiki
Red-tailed Black Cockatoo
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[Photo] Female Red-Tailed Black Cockato in flight. Photographed by Paul B. Adams on 8 April 2006 in Bourke NSW Australia. Date: 13 April 2006 (UTC). Author User Pbadams http://en.wikipedia.org/wiki/User:Pbadams
The Red-tailed Black Cockatoo (Calyptorhynchus banksii), also known as Banksian- or Bank's Black Cockatoo, is a large cockatoo native to Australia. This species was known as Calyptorhynchus magnificus for many decades until the current scientific name was officially conserved in 1994. It is more common in the drier parts of the continent. Five subspecies are recognised, differing most significantly in beak size. Although the more northerly subspecies are widespread, the two southern subspecies, the Forest Red-tailed Black Cockatoo and the South-eastern Red-tailed Black Cockatoo are under threat.
Adult Red-tailed Black Cockatoos are sexually dimorphic; males are large black cockatoos, 60 cm (24 inches) in length, with prominent red tail bands. Females are brownish-black with yellow barring and spotting and with yellow-orange tail stripes. The species is usually found in eucalyptus woodlands, or along water courses. In the more northerly parts of the country, these cockatoos are commonly seen in large flocks. They are seed eaters and cavity nesters. As such, they depend on trees with fairly large diameters, generally Eucalyptus. Populations in southeastern Australia are threatened by the reduction in forest cover and by other habitat alterations.
A Red-tailed Black Cockatoo, named Karak, was the official mascot of the 2006 Commonwealth Games, held in Melbourne. Of the black cockatoos, the red-tailed black is the most adaptable to aviculture, though they are much rarer and much more expensive outside Australia.
Taxonomy and naming
The species complex was first described by the ornithologist John Latham in 1790 as Psittacus banksii. That name commemorated English botanist Sir Joseph Banks. The Red-tailed Black Cockatoo also bears the honour of being the first bird from Eastern Australia illustrated by a European as a female presumably collected at Endeavour River in north Queensland was sketched by Banks' draughtsman Sydney Parkinson in 1770. Narrowly predating Latham, English naturalist George Shaw described Psittacus magnificus from a specimen collected somewhere in the Port Jackson (now Sydney) region. For many years, the species was referred to as Calyptorhynchus magnificus, proposed by Gregory Mathews in 1927 as Shaw's name had predated Latham's 1790 description. For several decades Mathews' proposal was accepted by many authorities, though it was unclear whether the original Port Jackson reference had actually referred to the Red-tailed Black or, more likely, the Glossy Black Cockatoo. In 1994, an application to conserve Calyptorhynchus banksii as the scientific name was accepted by the ICZN. The Red-tailed Black Cockatoo is the type species of the genus Calyptorhynchus, the name of which is derived from the Greek calypto-/καλυπτο- "hidden" and rhynchus/ρυγχο?? "beak". The change was first made by Anselme Ga??tan Desmarest in 1826.
In 1827 Jennings, proposed the name Psittacus niger for the bird, however this binomial combination had already been used by Linnaeus for the Lesser Vasa Parrot in 1758, and by Johann Friedrich Gmelin for the Palm Cockatoo in 1788 and was hence invalid even though both other species were at that time already known by different names.
Indigenous people of the central Cape York Peninsula have several names for the bird; (minha) pachang in Pakanh, (inh -) inhulg in Uw Oykangand, and (inh -) anhulg in Uw Olkola, the bracketed prefix (inh- or minha) is a qualifier meaning 'meat' or 'animal'. In Central Australia southwest of Alice Springs, the Pitjantjatjara term for the subspecies C. b. samueli is iranti. Karrak is a Noongar term derived from the call for the southwestern race C. b. naso.
The Red-tailed Black Cockatoo's closest relative is the Glossy Black Cockatoo; the two species form the subgenus Calyptorhynchus within the genus of the same name. They are distinguished from the other Black Cockatoos of the subgenus Zanda by their significant sexual dimorphism and calls of the juveniles; one a squeaking begging call, the other a vocalization when swallowing food. The Red-tailed was the only Black Cockatoo whose genetic material was used in a key molecular study of Cockatoo systematics in 1999 as generic rather than infrageneric relationships were being examined. Five subspecies are recognised, two of which are vulnerable. They differ mainly in the size and shape of the beak, the overall bird size and female coloration:
C. b. banksii is found in Queensland and rarely far northern New South Wales; it is the largest subspecies by overall body size though has a moderate-sized bill. It merges with subspecies macrorhynchus around the Gulf of Carpentaria. It has disappeared from much of its former range in northern New South Wales and southeast Queensland.
C. b. graptogyne, (Endangered) known as the South-eastern Red-tailed Black Cockatoo, is found in southwestern Victoria and southeastern South Australia in an area bordered by Mount Gambier to the west, Portland to the south, Horsham to the northeast and Bordertown to the north. The smallest of the five subspecies, this one was only recognised as distinct in the 1980s. It is predominantly dependent on stands of Eucalyptus baxteri (brown stringybark), Eucalyptus camaldulensis (river redgum) and Allocasuarina luehmannii (Buloke) for feeding and nesting. These tree species have been all threatened by land clearing and most remaining are on private land; possibly only 500???1000 individuals remain. The species and its habitat are the subject of a national recovery plan. In 2007 local landowners are being reimbursed for assisting in regenerating suitable habitat.
C. b. macrorhynchus, given the name Great-billed Cockatoo by Mathews, is found across northern Australia. Though thought to be widespread and abundant, this subspecies has been little studied. It is also large and has a large beak, as its subspecific name implies. Females lack red coloration in their tails.
C. b. naso (Near Threatened) is known as the Forest Red-tailed Black-Cockatoo and is found in the southwest corner of Western Australia between Perth and Albany. This form has a larger bill, and favours Marri (Corymbia (formerly Eucalyptus) calophylla), Jarrah (E. marginata) and Karri (E. diversicolor).
C. b. samueli exists in four scattered populations: in central coastal Western Australia from the Pilbara south to the northern Wheatbelt in the vicinity of Northam, and inland river courses in Central Australia, southwestern Queensland and the upper Darling River system in Western New South Wales. Birds of this subspecies are generally smaller with smaller bills than the nominate banksii.
Red-tailed Black Cockatoos measure around 60 cm (24 in) in length. The male's plumage is all black with a prominent black crest made up of elongated feathers from the forehead and crown. The tail is also black with two lateral bright red panels. Females are brownish black with yellow-orange stripes in the tail and chest,and yellow spots on the cheeks and wings. The bill is pale and horn-coloured. The underparts are barred with fine yellow over a brownish base. Male birds weigh between 670 and 920 g (1.5???2 pounds), while females weigh slightly less at 615???870 g (1.25???1.75 pounds).
Juvenile Red-tailed Black Cockatoos resemble females until puberty, which occurs around four years of age, but have paler yellow barred underparts. As the birds reach maturity, males replace their yellow tail feathers with red ones; it takes a bird approximately 18 months to moult and grow into its adult feathers.
These birds make several calls, including a contact call, a rolling metallic krur-rr or kree (given while flying), and a sharp alarm call.
As with other cockatoos, the Red-tailed Black Cockatoo can be very long-lived in captivity; in 1938 ornithologist Neville Cayley reported one over fifty years old at Taronga Zoo.
Distribution and habitat
The Red-tailed Black Cockatoo occurs across the drier parts of Australia. It is widespread and abundant in a broad band across the northern half of the country with more isolated distribution in the south. It has even been considered an agricultural pest there. Cockatoos are not migratory as such but do exhibit regular seasonal movements in different parts of Australia. In the northern parts of the Northern Territory, birds largely leave areas of high humidity in the summer wet season. In other parts of the country cockatoo seasonal movements tend to follow food sources as has been recorded in Northern Queensland, and New South Wales; in southwest Western Australia both subspecies there appear to have a north-south pattern; northwards after breeding in the case of subspecies naso, while movements by subspecies samueli in the wheatbelt can be irregular and unrelated to the seasons.
It is found in a wide variety of habitats, from shrublands and grasslands through eucalypt, sheoak and Acacia woodlands, to dense tropical rainforests. The bird is dependent on large, old eucalypts for nesting hollows, although the specific gums used vary in different parts of the country.
The birds are diurnal, raucous and noisy, and are often seen flying high overhead in small flocks, sometimes mixed with other cockatoos. Flocks of up to 500 birds are generally only seen in the north or when the birds are concentrated at some food source. Otherwise, they are generally rather shy of humans. In northern and central Australia, birds may feed on the ground, while the two southern subspecies, graptogyne and naso, are almost exclusively arboreal. Red-tailed Black Cockatoos tend to fly rather slowly with intermittent deep flapping wingbeats, markedly different to the shallow wingbeats of the similar Glossy Black Cockatoo. They also often fly at considerable height.
Though Red-tailed Black Cockatoos feed on a wide variety of native and introduced grains, the mainstay of their diet are eucalyptus seeds. There is a specific relationship between the species and larger-fruited species of gums. These vary across Australia but include the Marri in Southwest Western Australia, Darwin woolybutt E. miniata across the north of the country, E. baxteri in Victoria and the bloodwood species Corymbia polycarpa and C. intermedia in Queensland. Cockatoos bite off branchlets with clusters of seed capsules, then hold them with their feet while chewing and harvesting seeds before littering the ground with debris. Among other seeds and nuts consumed are those of Acacia, Allocasuarina, Banksia, Grevillea and Hakea, as well as berries, fruits and various insects and grubs. Cockatoos have adapted to eating some introduced plants such as the doublegee (Emex australis). There is some evidence of consumption of wild radish (Raphanus raphanistrum), wild turnip (Brassica tournefortii) and melon (Citrullus or Cucumis).
The male Red-tailed Black Cockatoo courts by puffing up crest and cheek feathers, and hiding the beak; it then sings and struts, ending in a jump and a flash of red tail feathers toward the female who will most often reply by defensively biting him. Breeding generally takes place from May to September except in the case of the South-eastern subspecies, which nests during summer (December to February). Pairs of the subspecies samueli in the Wheatbelt region of Western Australia may produce two broods, while those of South-eastern subspecies only brood once. Nesting takes place in large vertical tree hollows of tall trees. Isolated trees are generally chosen, so birds can fly to and from them relatively unhindered. The same tree may be used for many years. Hollows can be 1 to 2 m (3???7 ft) deep and 0.25???0.5 m (10???20 inches) wide, with a base of woodchips. A clutch consists of 1 to 2 white, lustreless eggs, though the second chick is in most cases neglected and perishes in infancy.
Relationship with humans
The Red-tailed Black Cockatoo is protected under the Wildlife Protection (Regulation of Exports and Imports) Act 1982, although the export of products may be permitted under Sections 10, 10A and 44 of the Act. Under Sections 11???13 and 27???31, live exports are allowed only for legitimate zoological and scientific purposes and not commercial purposes.
Internationally, these birds are listed under Appendix II of CITES, which allows international trade in live wild-caught and captive-bred specimens, if such exports are not detrimental to wild populations. However, the current Australian restrictions on commercial exports from Australia are not imposed by CITES.
Like many Australian cockatoos and parrots, the Red-tailed Black Cockatoo is threatened by the thriving illegal trade in bird smuggling. With high demand and high transit mortality means that many more birds are taken from the wild than actually sold. In 1997, the Northern Territory Government's Department of Natural Resources, Environment and The Arts (NRETA) proposed a management plan of C. b. macrorhynchus to stem the illegal trade in eggs and nestlings. This subspecies, which is relatively abundant in the territory's northern part, was thought plentiful enough to sustain limited harvesting of young for commercial purposes. This involved the protection of selected 'harvest zones' and the capping of harvest at 600 eggs or hatchlings per year; all captive birds were to be marked with microchips. Separate permits would be issued for collection and export, as well as keeping one as a pet.
The Northern Territory government's plan for a restricted harvest was supported by a group of biologists who argued that a 'do-nothing approach' had failed to address illegal trafficking and that limited public funds were available for species or habitat conservation. They felt that a catastrophic collapse in the Northern Territory population was highly unlikely, and that the cockatoo would benefit from increased awareness and a greater understanding of its biology by local landowners. There would also be a valuable contribution to the science of sustainable utilisation of wild resources.
Other experts raised serious concerns with the management plan; the famed psittacine biologist Joseph Forshaw opposed it on several grounds. He expressed concerns that, given the birds' short lifespan, recruitment problems may be masked for many years, by which time recovery of the cockatoo population may be impossible. He also feared that increasing supply would lower prices and hence lower profitability for those involved. Other groups such as the Avicultural Federation of Australia (AFA) raised concerns that populations may be aging due to lack of breeding sites, so they may be especially vulnerable to loss of juveniles which, again, may not be apparent for many years. They also feared that since adults mate for life, a bird whose partner was taken may not mate again.
To date the plan has not been implemented; the Australian Senate inquiry into the Commercial Utilisation of Australian Native Wildlife concluded in early 1998 that routine capture and commercial use of adult wild birds should be prohibited.
In the late 1990s, Red-tailed Black Cockatoos fetched prices of $1750 in Australia and $8900 (~US$6000) overseas. Hand-raised birds can sell for as little as AU$2500 in Australia, but prices may be anywhere from $15,000 to $40,000 in the United States where they are seldom seen in aviculture.
Hand-reared birds are able to learn a few words and can be quite affectionate, though males may become imprinted and unlikely to breed. The Red-tailed Black Cockatoo is the most commonly seen of the Black Cockatoos in captivity, and can be hardy and long lived if given plenty of space. Until now, most birds in captivity have been of subspecies C. b. banksii and C. b. samueli, though more members of subspecies C. b. macrorhynchus should become available. More aviculturists are concerned about maintaining the integrity of the separate subspecies in cultivation, and so avoid crossbreeding.
The birds breed easily in captivity and can lay eggs every 3 weeks between February and November. Once the female has one egg in her nest, she will not lay another. An egg takes about 30 days to hatch. The eyes of the young open around 3 weeks and the yellow down will show black pin feathers at about 6 weeks. The best time for hand raising is at about 10 weeks when their black feathers are in place but the tail feathers are still short. Young birds fledge after about 4 months. Mature male birds will become aggressive to young birds some time after fledging; they must be separated if caged.
Symbolism and folklore
A Red-tailed Black Cockatoo, named Karak, was the official mascot of the 2006 Commonwealth Games held in Melbourne. Promotion coincided with an implementation of initiatives to ensure the survival of the South-eastern subspecies graptogyne, as well as increased environmental awareness at the games.
The appearance of Red-tailed Black Cockatoos is supposed to foreshadow rain in some aboriginal cultures.
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