Banks' Black cockatoo, Great-billed cockatoo
The Red-tailed black-cockatoo has a crest which forms a helmet when the bird raises it and pushes it forward. Adult males have a characteristic pair of bright red panels on the tail that gives the species its name. The female has duller plumage with yellow spots on her head, wings and neck. Her underbody has bars of pale orange-yellow with orange-yellow panels on the tail, barred black.
The Red-tailed black-cockatoo is a native of Australia and more widespread in the northern drier parts of the continent. They live in open country as well as forests. It prefers Eucalyptus woodlands and riverside trees, but it can live in a wide variety of habitats, including subtropical rainforest, farmland with scattered Eucalyptus or grasslands with scattered trees.
Red-tailed black cockatoos are diurnal and raucous, and are often to be seen flying in small flocks high overhead, sometimes alongside other cockatoos. Flocks as big as 500 are usually seen only in the north or concentrated at a food source. They depart from their communal roost early in the morning to drink at a regular place, then disperse widely to feed. They remain sheltered in foliage around the middle of the day, and return to the feeding areas late in the afternoon. The flock returns to its roosting trees near water at the close of day. In central and northern Australia, the cockatoo feeds in trees or on the ground. Southern species feed mostly in the trees. These cockatoos are not wholly migratory, but they do exhibit regular seasonal movements in different parts of Australia.
These cockatoos eat mainly seeds, but also fruits, nuts, bulbs, flowers, and insects. It can eat either in the tree canopy or on the ground. Favorite seeds are eucalypts, acacias, casuarinas, and banksias.
The Red-tailed black cockatoo is monogamous, mating for life. If it happens that one of the pair disappears, the other may choose not to mate again. Maturity is reached within about 4 years. Mating takes place usually between May and September except for the south-eastern bird, which nests during the summer (December to February). The cockatoo nests in tree hollows or in dead trees, and they must be tall trees. They line the hollow with decayed and chewed wood. The female lays 1 egg, occasionally 2. Only 1 chick will be raised. Incubation is carried out just by the female, for about 28 to 30 days. The female is fed by the male during incubation. The chick is fed by both parents. The young depends on its parents for food for about 3 months. It may fledge at about 100 days of age, when it has reached adult size.
As with many Australian parrots, the cockatoo is threatened by bird smuggling and is the most often observed in captivity. Other threats are habitat modification, clearing for forestry and agriculture or forestry, urban development and also climate change.
According to IUCN, the Red-tailed black cockatoo population is believed to be in excess of 100,000 individuals. The Northern subspecies of Red-tailed black cockatoo is widespread and is not considered endangered. Just in the Northern Territory there are about 60,000 birds. The Southeastern subspecies, however, is considered endangered. In 2001 there were estimated to be only 650-1000 birds in the population, including 500-770 adults. The ICUN lists the red-tailed black cockatoo as a "Least Concern”, with a decreasing population trend owing to ongoing habitat destruction.
