Red-tailed Black Cockatoo

(Calyptorhynchus banksii naso)

Range and Habitat

Calyptorhynchus banksii naso is a resident species in Western Australia’s southwest corner. Their association with the habitat of Marri, Jarrah and Karri forests gives them their common name of the forest red-tailed black cockatoo.

They range from north of Perth in the Gingin area, south through the outer metro region and hills area of Perth, and south to Augusta and Albany. Populations spread east to Mount Helena, Christmas Tree Well, North Bannister, Mt Saddleback, Rocky Gully and the upper King River.

Over recent years they have moved further into the metro region, taking advantage of food and water opportunities provided by nature reserves and remnant bushland areas like Jirdarup Bushlands in the Kensington area, very close to inner city areas of Perth itself. They also frequently visit dams and water troughs on rural properties on the outskirts of Perth close to forest areas.

Conservation Threats

Currently listed as Vulnerable, the Forest red-tailed black cockatoo range has reduced by 30% in the past 60 years or more. The ongoing clearing of their forest habitat, resulting in a loss of food sources and available nesting hollows, has continued to cause a decline in their numbers. Other contributing factors include illegal shootings by orchardists, collisions with motor vehicles, and losing nest sites to feral bees and native ducks.

Bushfires can also destroy their habitat and hollows, impacting their reproduction. The average age of trees large enough to develop a nesting hollow is over 200 years old. Despite its conservation status, old growth forest with available nesting hollows continues to be logged. As a result, trialling of artificial nests has begun.

Behaviour

The species forms loose flocks of up to 50 birds consisting of smaller family groups numbering up to 10, in some ways like a community. Pairs mate for life and often venture less than 20km from their nesting hollows. As a sedentary species, the destruction of nest sites is very damaging.

They are highly vocal, calling to each other constantly while feeding and flying. Amongst a variety of loud, harsh calls is their distinctive ‘karrak’ sound which is the origin of their Noongar aboriginal name ‘Karrak’.

Breeding

Pairs lay one egg, rarely two, and raise only one chick. The female incubates and broods the hatchling while the male provides food to the female until the chick is large enough for the hen to leave the nest for periods and search for food. Chicks are born after 29–31 days, covered with long soft yellow down.

Description

Forest red-tailed black cockatoos are solidly built with a more prominent, broader mandible than other sub-species in Western Australia. The size of their mandible is the origin of their scientific name, ‘naso’. In addition, they have a full, rounded crest giving them the appearance of having a large head.

Males are glossy black, more gunmetal grey than the other sub-species of the Calyptorhynchus genus. They have a broad band of solid red in their tail feathers, visible when flying and during their courtship display. The beak is dark grey, and the eyes are black.

The female is black with pale yellow spots on the head, crest and wing coverts, and the tail has narrow red and yellow-orange stripes. Chest feathers also have orange-yellow barring. Their tail feathers spread when flying and landing, producing an impressive display. The female beak is greyish-white.

Juveniles are variable in markings resembling adult females, but the mandible is often dark, and the spots and chest barring are often darker gold and irregular. Young males begin the lose their spots and stripes in their second year and replace the striped tail feathers with solid red ones. They will have a full red tail by the time they are four years of age.

Length 53–55 cm. Weight 600–610 g.

Lifespan

Approximately 25 to 50 years in the wild, potentially longer in captivity.

Adult male tail feather (top) and adult female tail feather (bottom).