Matomo-Image-Tracker Psittaciformes - Calyptorhynchus - Red Tailed Black Cockatoo

Psittaciformes

Red Tailed Black Cockatoo - Calyptorhynchus Banksii


The red-tailed black cockatoo (Calyptorhynchus banksii) also known as Banksian- or Banks' black cockatoo, is a large black cockatoo native to Australia. Adult males have a characteristic pair of bright red panels on the tail that gives the species its name. It is more common in the drier parts of the continent. Five subspecies are recognized, 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. 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, and as such depend on trees with fairly large diameters, generally Eucalyptus. Populations in southeastern Australia are threatened by deforestation and other habitat alterations. Of the black cockatoos, the red-tailed is the most adaptable to aviculture, although black cockatoos are much rarer and much more expensive in aviculture outside Australia.

Description


Red-tailed black cockatoos are around 60 centimeters (24 in) in length and sexually dimorphic. The male's plumage is all black with a prominent black crest made up of elongated feathers from the forehead and crown. The bill is dark grey. The tail is also black with two lateral bright red panels. Females are black with yellow-orange stripes in the tail and chest, and yellow grading to red spots on the cheeks and wings. The bill is pale and horn-colored. The underparts are barred with fine yellow over a black base. Male birds weigh between 670 and 920 grams (1.5–2 lb), while females weigh slightly less at 615–870 grams (1.25–1.75 lb). In common with other cockatoos and parrots, red-tailed black cockatoos have zygodactyl feet, two toes facing forward and two backward, that allow them to grasp objects with one foot while standing on the other, for feeding and manipulation. Black cockatoos are almost exclusively left-footed (along with nearly all other cockatoos and most parrots). Juvenile red-tailed black cockatoos resemble females until puberty, which occurs around four years of age, but have paler yellow barred underparts.[25] As the birds reach maturity, males gradually replace their yellow tail feathers with red ones; the complete process takes around four years. 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. Another bird residing at London and Rotterdam Zoos was 45 years and 5 months of age when it died in 1979.

Classification

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.[14] 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.

Five subspecies are recognized; they differ mainly in the size and shape of the beak, the overall bird size and female colouration:

C. b. banksii is found in Queensland and, rarely, in far northern New South Wales; it is the largest subspecies by overall body size and has a moderate-sized bill.

C. b. graptogyne, (Endangered) known as the south-eastern red-tailed black cockatoo, is found in southwestern Victoria and southeastern South Australia

C. b. macrorhynchus, given the name great-billed cockatoo by Mathews,[34] is found across northern Australia.

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.

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.


Distribution and Habitat


The red-tailed black cockatoo principally occurs across the drier parts of Australia. It is widespread and abundant in a broad band across the northern half of the country, where it has been considered an agricultural pest, with more isolated distribution in the south. It is found in a wide variety of habitats, from shrub-lands and grasslands through eucalyptus, she-oak and Acacia woodlands, to dense tropical rainforests.[5] The bird is dependent on large, old eucalypts for nesting hollows, although the specific gums used vary in different parts of the country. Cockatoos are not wholly migratory, but they do exhibit regular seasonal movements in different parts of Australia. In the northern parts of the Northern Territory, they 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.

Behavior


Red-tailed black cockatoos 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. They tend to fly rather slowly with intermittent deep flapping wingbeats, markedly different from the shallow wingbeats of the similar glossy black cockatoo. They also often fly at considerable height.

Breeding

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 produce one. 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 meters (3–7 ft) deep and 0.25–0.5 metros (10–20 in) wide, with a base of wood chips. A clutch consists of 1 to 2 white, lusterless eggs, although the second chick is in most cases neglected and perishes in infancy.[54]

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Psittaciformes, The Parrot Index, a part of Phoenix Feathers © 2016 - 2023
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