Plants and Animals Index

Cockatoo

There are 21 species of bird that can be called Cockatoos.  These species belong to the family Cacatuidae.  Along with the Psittacidae family (the true parrots), they make up the order Psittaciformes.

Cockatoos and parrots share many characteristic features including the curved shape of the beak and a zygodactyl foot (a foot with two toes facing forward and two toes facing backward). 

There are also significant differences between Cockatoos and parrots.  Cockatoos have the spectacular movable head crest we recognise but they lack the beautiful bright blues and green seen in the feathers of true parrots.  There are also some differences in anatomical details, for example - Cockatoos have gall bladders and parrots do not.  The Cockatoo species are also, on average, larger than the true parrots.  The cockatiel is a small cockatoo not a parrot. 

Cockatoos have a much more restricted range than the true parrots, occurring naturally only in Australia and nearby islands.  Eleven of the 21 species exist in the wild only in Australia, while seven species occur in Indonesia, New Guinea, and other south Pacific islands.  Three species occur in both New Guinea and Australia.

There are four members of the Cacatua genus found in the Murray Darling Basin:

          Sulphur-crested Cockatoo               Cacatua galerita

          Short-billed Corella                          Cacatua sanguinea

          Eastern Long-billed Corellas             Cacatua tenuirostris

          Major Mitchell Cockatoo                 Cacatua (Lophocroa) leadbeateri

The classification of the Major Mitchell Cockatoo, Cacatua (Lophocroa) leadbeateri is not yet fully resolved however the tendency is to place it in its own Genus Lophocroa

Description

The Sulphur-crested Cockatoo is easily recognised and is an iconic bird of Australia.  This Cockatoo is a large white bird with a dark grey-black bill, a distinctive sulphur-yellow crest and a yellow wash on the underside of the wings. 

The male and female Sulphur-crested Cockatoo are very similar at a distance.  At close range the sexes can be distinguished by their eye colour, the male has a dark brown eye and the female has a lighter reddish brown eye colour.  Young Sulphur-crested Cockatoos closely resemble the adults.

Adult Sulphur-crested Cockatoos range in size from 45cm to 50cm, with an average size of 48cm.  They weigh, on average, 633gm.

The Sulphur-crested Cockatoo is a noisy and conspicuous cockatoo, both at rest and in flight.  Their most common call is a very distinctive loud screech.

Habitat

Sulphur-crested Cockatoos are common and familiar in Australia.  Their range extends throughout the northern and eastern mainland, and Tasmania. 

Sulphur-crested Cockatoos are found in a variety of timbered habitats and are common around cities, towns and smaller settlements.  The birds stay in the same area all year round.

The Sulphur-crested Cockatoo can also be found in New Guinea and in the Aru Islands.

Behaviour

The Sulphur-crested Cockatoos' normal diet consists of berries, seeds, nuts and roots.

Feeding usually takes place in small to large groups.  While most of the group feed some members of the group will be on the lookout for danger, watching from nearby perches.

When they are not feeding, these birds will bite off smaller branches and leaves from trees.  They do not eat these items.  It is thought that this activity may help keep their beak trimmed and stop it from growing too large.

The Sulphur-crested Cockatoos' breeding season is from August to January in the south and from May to September in the north.  The female lays one to three eggs in a suitable tree hollow which has been prepared by both the male and female of the pair.  Both birds also incubate the eggs and care for the chicks which hatch after about 30 days.  The chicks leave the nest after a further 60 to 70 days, but remain with the parents all year round.  Family groups will stay together indefinitely.

Notes

The Sulphur-crested Cockatoo is similar in appearance to the three species of Corella found in Australia.  Corellas are smaller, however, and lack the prominent yellow crest.

Their popularity as a cage bird has increased the range of the Sulphur-crested Cockatoo, as these birds either escape or are released deliberately in areas where they do not naturally occur.  For example, a small population has become established around Perth, Western Australia.  The Sulphur-crested Cockatoo has also been introduced into New Zealand and Indonesia.

References/Sources

Crome, F.  and Shields, J.  1992.  Parrots & Pigeons of Australia.  Angus and Robertson and the National Photographic Index of Australian Wildlife, Sydney.

Moorecombe, Michael.  2000.  Field Guide to Australian Birds.  Steve Parish Publishing.  Archerfield, Australia.  ISBN 1-876282-10-X

Slater, Peter, Pat and Raoul.  The Slater Field Guide to Australian Birds.  Revised Edition.  1989.  Lansdowne Publishing, Sydney.  ISBN 0-947116-99-0

Pizzey, Graham.  1980.  A Field Guide to the Birds of Australia.  Collins, Sydney.  ISBN 0-00-219201-2

Higgins, P.J.  (ed) 1999.  Handbook of Australian, New Zealand and Antarctic Birds, Volume 4 (Parrots to Dollarbird).  Oxford University Press, Victoria.

Schodde, R.  & Tidemann, S.C.  (eds) 1990.  Reader's Digest Complete Book of Australian Birds (2nd Edition).  Reader's Digest (Australia) Pty Ltd, Sydney.

Website: Birds in Backyards

Website: Sulphur-crested Cockatoo, Australian Museum