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Monday, 18 Dec 2017

White-tailed Black Cockatoo

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There are two species of white-tailed black cockatoo - Baudin's Cockatoo and Carnaby's Cockatoo - that are endemic to the south-west corner of Western Australia. They form a very conspicuous part of the avifauna, with their large flocks and their distinctive wailing calls.

Baudin's Cockatoo Calyptorhynchus baudinii was named in honour of the French explorer Captain Nicolas Thomas Baudin (1754-1803) by Edward Lear, an ornithologist and illustrator, at the British Museum in 1832. Baudin visited Western Australia in early 1801 and the type specimen probably came from the vicinity of Cape Naturaliste. Carnaby's Cockatoo Calyptorhynchus latirostris was named in 1948 after Ivan Carnaby, a Western Australian naturalist.

The two species are very difficult to tell apart, especially in the Perth hills area where both species regularly occur and sometimes feed and roost close together. Their bill size and shape and their different contact calls are the most reliable means of identification. Baudin's Cockatoo has a long, narrow upper bill and makes a short "whicha-whicha" and "bunyip-bunyip" flock call whereas Carnaby's Cockatoo has a short, thick upper bill and has a longer "weeeloo-weeeloo" flock call.

Both species are listed as ‘Endangered' and both have suffered a substantial decline in numbers and breeding distribution in the past fifty years. Direct causes of population decline include land clearing and fragmentation of habitat (especially in the Wheatbelt for Carnaby's Cockatoo), the loss of food trees and hollow-bearing trees (veteran and stag trees over 230 years of age), large numbers shot by orchardists (illegal shooting mainly with Baudin's Cockatoo) and the impact of hollow competitors including the Galah, corellas and the feral European honey bee. Since European settlement in Western Australia around 90% of the original vegetation in the south-west has been cleared for agriculture, cities and towns, mining and timber production. The region is now a severely fragmented landscape and the loss of remnant vegetation, the lack of regeneration, the changing fire regimes, lack of suitable breeding sites, competition with exotic species and climate change all exacerbate the future conservation of cockatoos in this region. Roleystone residents are indeed fortunate in having both of these endangered species as regular visitors to the neighbourhood.

Baudin's Cockatoo breeds mainly in the Karri forest block in the deep south-west then migrates northwards between March and September to winter in the central and northern Darling Range including Chidlow, Mundaring, Araluen, Wungong Valley and the Serpentine-Jarrahdale area. Overall it is most numerous in the deep south-west during the spring breeding season, September-December and in the northern Darling Range during autumn April-August. During the autumn-winter non-breeding season Baudin's Cockatoos use traditional roost sites and one of the largest of these at Araluen sometimes contains as many as 800 birds. They feed on a wide range of foods including the seeds of Marri, Jarrah, Banksia, also nectar, buds and flowers, insect larvae from under bark and they are also attracted to fruiting apples and pears. Overall Marri is its main food source and the birds use their long bill to extract the seeds without chewing into the nut (see below).

Carnaby's Cockatoo breeds mainly in the Wheatbelt or semiarid interior of Western Australia and in the non-breeding season migrates westward and southwards into wetter coastal areas especially Banksia scrubs and pine plantations on the Swan Coastal Plain. Due largely to this migration, they have become part of Perth folklore. For many Perth residents the appearance in autumn of migrating flocks of Carnaby's Cockatoos with their distinctive calls, has earned them the reputation as harbingers of rain. They feed mainly on the seeds and nectar of Banksia, Dryandra, Eucalyptus and Grevillea and are attracted to seeding pines and also fruiting almonds.

There is no doubt that the conservation of these cockatoos provides us with a great challenge for the future. Over the past ten years the Western Australian Museum has been carrying out a research program looking at the distribution and ecology of Baudin's, Carnaby's and Forest Red-tailed Black Cockatoos throughout the south-west. This project relies on museum staff, volunteers as well as the support and involvement of the community. Sightings of black cockatoos from the Roleystone region are welcome and can be sent to the Cockatoo Care Data Co-ordinator at the WA Museum, Locked Bag 49, Welshpool DC, WA, 6986.

Information should include your name and address (for any follow-up), location, date and time (if known) of sighting, whether call was heard, number of birds seen and what the birds were doing (flying overhead, feeding [on what], drinking, roosting etc.) and any other relevant notes. A Frequent Sighting form can be downloaded from http://www.museum.wa.gov.au/cockatoocare/sighting.asp that can be sent after completion.

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Baudin's Cockatoo (female) with a long upper bill.

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Carnaby's Cockatoo (female) with a short upper bill.

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Marri nuts with seeds extracted with finesse by the long upper bill of Baudin's Cockatoo.

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A less-elegant approach to extract the Marri seeds by Carnaby's Cockatoo with its short upper bill.

White-tailed cockatoos eat seeds of and enjoy the nectar of flowers including:

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(Banksia) Dryandra nivea

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(Banksia) Dryandra sessilis

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Hakea undulata

Baudin's Cockatoo relish fresh insect larvae:

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Grubs from Banksia cones

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Insect larva example

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Foraging on a dead Balga

Note:

This article was submitted by Cockatoo Care.
Photo images are the copyright of Tony Kirkby and Kim Sarti.

 

© Roleybushcare 2017