BIRD FAMILIES OF THE WORLD
 
 
a web page by Don Roberson
 
 
COCKATOOS Cacatuidae
  • 21 species in Australasia and islands off southeast Asia
  • DR personal total: 9 species (43%), 4 photo'd

Cockatoos are a family of (mostly) large psittaciformes in Australasia, although they range from Australia to the Bismarck Archipelago and the Philippines. They differ from other parrot-like birds in various internal ways (e.g., they have a gall bladder), their downy hatchlings, and the lack of green or blue in their plumage. Thirteen of the 21 cockatoos are white or mostly white, including such large birds as Sulphur-crested Cockatoo (left) of east and north Australia and New Guinea.

Cockatoos are striking birds of forest, eucalypt woods, or more open country, depending on species. Coming as I do from the northern hemisphere, I was very impressed by my first view of such a big white bird in flight. The size and manner of flight strongly recalled Snowy Owl to me, and I've had that strange image ever since.

Another 7 of the cockatoos are black, blackish, or gray; an example is Yellow-tailed Black-Cockatoo of southeast Australia (right, in a wonderful shot by Hans & Judy Beste). These big dark birds are also very impressive in flight. The five species of black-cockatoo somewhat replace each other geographically, except in southwest Australia where two very similar species occur sympatrically, and survive because they differ in bill length and thus eat different seeds.

While the molecular (de Kloet & de Kloet 2005) and morphological evidence (e.g., Homberger 1991) has shown that cockatoos are an ancient and distinct lineage within the psittaciformes, whether to separate them as a family is debated. Dickinson (2003) preferred to keep all the psittaciformes in one family. The Handbook of the Birds of the World series split the psittacines into two families: parrots and cockatoos (Rowley 1997). Christidis & Boles (2008) add a further family to that set — New Zealand parrots [Nestoridae] — and others have proposed even more splits. For the moment, I follow Christidis & Boles (2008) in a three-way split.

The most widespread cockatoo in Australia is Galah (below), with its rosy face and underparts, white crown, and gray upperparts. It was once a bird of the arid interior but, as it is well adapted to open country, has expanded its range with human settlement and agricultural development (Rowley 1997). Galah are sociable birds and can be found in flocks up to 1000 birds. Like most parrots, cockatoos are monogamous and pair for life. These two (below) appeared to be mates.

The three corellas in Australia are smaller white cockatoos of open country. This is Long-billed Corella of the southeast (left & below). The one (left) had a favored century plant in the center of the little town of Deniliquin, New South Wales, and you can see how it has ripped up that plant while sharpening its bill.

On my first trip to Australia with two friends, we took turns driving the rental car. My friend Steve was driving when I spotted what looked like a bunch of birds out in a field, so I suggested that we turn around and check them out. "Nah," said Steve, who had seen them from the corner of his eye, "it was just a field full of sheep." But I insisted that they were birds, so we went back — and found a flock of Little Corella Cacatua sanguinea. A flock of Long-billed Corella on the ground (below) can still give one that same image — and of course I now think "sheep" when I encounter such a flock.

Cockatiel Nymphicus hollandicus is the smallest member of this family; it wanders erratically throughout the Australian interior. Many Cockatiel are now bred in captivity, where it is among the most popular of all cage-birds.

Seven cockatoos are found on islands between New Guinea and the Philippines; four of them are globally threatened (Birdlife International 2000). One of those is the beautiful Philippine (or Red-vented) Cockatoo Cacatua haematuropygia, a Philippine endemic and now rare and local to a few of the southern islands. When I first visited the Philippines in 1990, our group saw a pair on the Palawan Island mainland, where a pair flew over us as we walked along a stream. I wrote: "This is a lovely white small cockatoo; a bit of yellow wash to the back of the head & bright salmon undertail coverts." When I returned to the Philippines 15 years later, this species was almost entirely gone from the main forest of Palawan, and there were no longer any predictable spots of occurrence. To see it, one took a boat to a tiny offshore islet, and watched a few fly in at dusk. Views were limited to white birds in flight a long distance away from a rocking dinghy. The experience is no longer the same. Let's hope, though, that they will make a comeback in the future.

 

Photos: The Sulphur-crested Cockatoo Cacatua galerita was in Royal Nat'l Park, New South Wales, Australia, in Dec 1997. Hans & Judy Beste photographed the Yellow-tailed Black-Cockatoo Calyptorhunchus funereus in eastern Australia. The pair of Galah Eolophus roseicapillus and the Long-billed Corella Cacatua tenuirostris were at Deniliquin, New South Wales; the Galah on 1 Jan 1998, and the corellas on 31 Dec 1997. Photos © Don Roberson, except for the black-cockatoo © Hans & Judy Beste, used with permission; all rights reserved.

Bibliographic note: Cockatoos have been traditionally covered by books covering psittaciformes; see reviews of family books on my Parrots page.

Literature cited:

Birdlife International. 2000. Threatened Birds of the World. Barcelona, Lynx Edicions.

Christidis, L, and W.E. Boles. 2008. Systematics and taxonomy of Australian Birds. CSIRO Publ, Sydney.

de Kloet, R.S., and S.R. de Kloet. 2005. The evolution of the spindlin gene in birds: Sequence analysis of an intron of the spindlin W and Z gene reveals four major divisions of the Psittaciformes. Molec. Phylog. Evol. 36: 706-721.

Dickinson, E., ed. 2003. The Howard & Moore Complete Checklist of the Birds of the World. 3d ed. Princeton Univ. Press, Princeton, N.J.

Homberger, D.G. 1991. The evolutionary history of parrots and cockatoos: a model for evolution in the Australasian avifauna, in Acta XX Congress Internationalis Ornitholigici (Bell, B.D., et al., eds.). Vols. 1–4. New Zealand Ornithol. Congress Trust Board, Wellington.

Rowley, I. 1997. Family Cacatuidae (Cockatoos), pp. 246 –279 in Handbook of the Birds of the World (del Hoyo, J., A. Elliott & J. Sargatal, eds). Vol. 4. Lynx Edicions, Barcelona, Spain.

Sibley, C.G., and J.E. Ahlquist. 1990. Phylogeny and Classification of Birds: a Study of Molecular Evolution. Yale Univ. Press, New Haven, CT.

 
 

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