Carnaby's black cockatoo (Zanda latirostris), also known as the short-billed black cockatoo, is a large black cockatoo endemic to southwest Australia. It was described in 1948 by naturalist Ivan Carnaby. Measuring in length, it has a short crest on the top of its head. Its plumage is mostly greyish black, and it has prominent white cheek patches and a white tail band. The body feathers are edged with white giving a scalloped appearance. Adult males have a dark grey beak and pink eye-rings. Adult females have a bone-coloured beak, grey eye-rings and ear patches that are paler than those of the males.
This cockatoo usually lays a clutch of one to two eggs. It generally takes 28 to 29 days for the female to incubate the eggs, and the young fledge ten to eleven weeks after hatching. The young will stay with the family until the next breeding season, and sometimes even longer. The family leaves the nesting site after the young fledge until the following year. Carnaby's black cockatoo forms flocks when not breeding, with birds in drier habitats usually being more migratory than those in wetter ones. It flies with deep and slow wingbeats, generally high above trees. Seeds of plants of the families Proteaceae and, to a lesser extent, Myrtaceae form a large part of its diet.
Carnaby's black cockatoo nests in hollows situated high in trees with fairly large diameters, generally Eucalyptus. With much of its habitat lost to land clearing and development and threatened by further habitat destruction, Carnaby's black cockatoo is listed as an endangered species by the Federal and Western Australian governments. It is also classified as endangered by the International Union for Conservation of Nature (IUCN). Like most parrots, it is protected by CITES, an international agreement that makes trade, export, and import of listed wild-caught species illegal.
Taxonomy and naming Carnaby's black cockatoo and Baudin's black cockatoo were once known collectively as the white-tailed black cockatoo (Calyptorhynchus baudinii) until formally classified as separate species. In a 1933 report on the birds of Lake Grace, Western Australian naturalist Ivan Carnaby wrote of a distinctive population of white-tailed black cockatoos that he named mallee black cockatoos. These birds lived in mallee and sandplains, using their large bills to crack open woody seed pods; the typical form had a long narrow bill it used to extract eucalypt seeds from marri seed pods. He classified the large-billed form as a subspecies of the white-tailed black cockatoo in 1948, giving it the name Calyptorhynchus baudinii latirostris. The epithet latirostris is from the Latin "wide" and "bill". The holotype specimen is from Hopetoun, Western Australia.
Among the black cockatoos, the two Western Australian white-tailed species (Carnaby's and Baudin's black cockatoos), together with the yellow-tailed black cockatoo (Z. funerea) of eastern Australia, form the genus Zanda. The two red-tailed species, red-tailed black cockatoo (C. banksii) and glossy black cockatoo (C. lathami), form the genus Calyptorhynchus. The three species of Zanda were formerly included in Calyptorhynchus (and still are by some authorities), but are now widely placed in a genus of their own due to a deep genetic divergence between the two groups. The two genera differ in tail colour, head pattern, juvenile food begging calls and the degree of sexual dimorphism. Males and females of Calyptorhynchus sensu stricto differ markedly in appearance, whereas those of Zanda have similar plumage.
The three species of the genus Zanda have been variously considered as two, then as a single species for many years. During the 1970s, Australian ornithologist Denis Saunders analysed the two white-tailed taxa and found that Baudin's black cockatoo also has a longer wing, and wider and higher skull than Carnaby's black cockatoo. Furthermore, there was no overlap in the range of (bill) lengths. In a 1979 paper, Saunders highlighted the similarity between the short-billed and the southern race xanthanotus of the yellow-tailed and treated them as a single species with the long-billed as a distinct species. He proposed that Western Australia had been colonised on two separate occasions, once by a common ancestor of all three forms (which became the long-billed black cockatoo), and later by what has become the short-billed black cockatoo. An analysis of protein allozymes published in 1984 revealed the two Western Australian forms to be more closely related to each other than to the yellow-tailed, and the consensus since then has been to treat them as three separate species.
The two white-tailed cockatoo species were called short-billed and long-billed black cockatoos in scientific works, yet they were called Carnaby's and Baudin's black cockatoo in Western Australia. Hence ornithologists Les Christidis and Walter Boles pushed for the latter two names to be used. The International Ornithologists' Union has taken up this suggestion and uses these names as their official common names.
The local Noongar people did not distinguish between Carnaby's and Baudin's black cockatoos. Nyungar names recorded include ngolyenok and ngoolyoo (from Northampton).
Description
Carnaby's black cockatoo is in length with a wingspan, and weighs 520–790 grams. It is mostly greyish black, with narrow light grey scalloping produced by narrow off white margins at the tips of dark feathers. The scalloping is more prominent on the neck. It has a crest of long feathers on its head that form a short crest that can be raised and lowered, and a prominent off-white patch of feathers on its cheek. Its lateral tail feathers are white with black tips, and the central tail feathers all black. The irises are dark brown and the legs brown-grey. Its beak is shorter and broader than that of the closely related and similar Baudin's black cockatoo; the two are often difficult to distinguish in the field.
The adult male has a dark grey beak and pink eye-rings. The adult female has a bone-coloured beak, grey eye-rings and ear patches that are whiter and more distinctive than those of the male. The feathers of its underparts and underwing coverts have larger white margins than those of the male, leading to a more barred or scalloped pattern to its plumage. Its legs and feet are a little lighter than those of the male. Moulting appears to take place in stages in late summer—some time between January or February and April or May, and is poorly understood.
Juveniles have a bone-coloured beak, grey eye-rings, and less white in the tail feathers. They can also be distinguished by their constant begging calls. It is not possible to tell the sexes apart until the male's bill begins to darken. This begins when the male is around one year old, and is complete some time after two years of age.
Distribution and habitat
Carnaby's black cockatoo is found across a broad swathe of southwest Australia—mostly within the Wheatbelt region—in places that receive over of rainfall yearly. The limits of its range include Cape Arid to the east, Lake Cronin, Hatters Hill and Lake Moore inland, and Kalbarri to the north. Breeding takes place in areas receiving rainfall a year, from the Stirling Range to Three Springs as well as around Bunbury. The cockatoo pairs form flocks outside the breeding season, moving away from nesting areas. Carnaby's black cockatoo is sedentary in wetter parts of its range, and migratory in drier areas as birds move south and west towards the coast in summer.
Carnaby's black cockatoo is found in Eucalyptus woodland, most commonly of wandoo (Eucalyptus wandoo) or salmon gum (E. salmonophloia). It is also found nearby pine plantations and sandplains or kwongan heath with abundant Hakea, Banksia, and Grevillea shrubs.
Behaviour Carnaby's black cockatoo communicates by auditory and visual displays. The voice is generally noisy with several calls; loudest and most frequent is a wailing wy-lah, which is uttered by both sexes and often heard before the birds themselves are seen. There is usually an interval of 0.4 seconds before the call is repeated. This call is made by birds in flight, before taking off and returning to the nest. Carnaby's black cockatoos that are not in flight may answer with this call when they hear it. The call is often shortened or chopped off three-quarters of the way through as the bird takes off. The call varies between individual Carnaby's black cockatoos, and older nestlings can distinguish their parents' calls. Saunders labelled a variant of the wy-lah as the interrogative call—it is drawn out and ends with an inflection. Birds often utter a soft chuck call when alone. Females make a whistling call composed of two notes of varying volume when perched or about to take off. They also utter a softer version that is 0.6 seconds long, as well as a long single-noted whistle when alone. The male makes a soft shot wy-lah call in similar situations. Birds may also make a harsh screeching alarm call when they notice something is out of place. They squawk loudly in disputes with their own kind, when other animals enter breeding territory, or when they are handled by people in captivity. Males can utter a harsh chattering squeak when arguing with other males.
Males make two calls that are directed at females, sometimes as a prelude to mating. One is a sequence of short squeaks; the other is made up of consecutive ah notes with 0.1 second between each note. These calls can be brief or last up to several minutes. Nestlings make a noisy grating begging call when seeking or expecting food. An adult female may also make the call while incubating the eggs. Immature birds also make a grating call not associated with begging that parents ignore.
Carnaby's black cockatoo flies with deep, slow wingbeats, giving it a wavelike movement. It can also glide for extended periods with its wings held downwards. Flocks generally fly at height, descending to treetops to feed or roost. Birds can be agile, manoeuvring quickly if startled or disturbed. In contrast, they waddle awkwardly on the ground.
Previously, the maximum age recorded from banding was 25 years 10.8 months for a bird banded in November 1988 at Coomallo Creek and encountered in a field 5 km away at Tootbardie in October 2014. However, in October 2021, a male individual was discovered to be alive and still nesting at the age of 35, having first been tagged in 1986. The bird was discovered six kilometres from where it had been originally tagged.
Breeding Carnaby's black cockatoos begin breeding from four years of age and mate for life. Mature wandoo and salmon gum woodlands provide important breeding habitat for the cockatoos as they need large hollows in tall trees. The nests are generally located about above the ground, and spaced away from each other, on average. There is competition for nest hollows with western corellas (Cacatua pastinator), galahs (Eolophus roseicapilla), and feral honeybees (Apis mellifera). Galahs seek out hollows at any time of year, unlike the Carnaby's black cockatoos, which only look before breeding. Mated pairs return to a breeding locale in late winter and begin preparing to breed, the female choosing a suitable hollow in a tree. She becomes highly territorial, driving off other females from the vicinity of the nest. After a bushfire burnt out much of the species' breeding habitat in 2009, local wildlife officers of the Department of Parks and Wildlife in Western Australia constructed artificial breeding hollows. After some experimentation by authorities, the survival rate of nestlings in these hollows increased to 75%.