The Sulfur-crested cockatoo is large and white parrot with a distinctive yellow crest on top of their head which they can raise or leave folded down. Their beak is dark grey-black. The underside of the wings and tail is a paler yellow. Females and males look the same but females have red tinted brown eyes, while the eyes of males are darker brown.
The Sulfur-crested cockatoo is found in large numbers in the east and north of Australia and most of New Guinea with nearby smaller islands. It also lives in Western Australia, Singapore, Palau, Taiwan, Puerto Rico and New Zealand as an introduced species. They live in areas with trees, such as tropical and subtropical rainforests. The vast savannas in northern Australia are also their home. They can be found in urban and suburban areas, particularly in parks and gardens.
This cockatoo is a diurnal gregarious bird, and flocks from a dozen up to several hundred will form. At sunrise the fly from the roosting grounds to feeding grounds, flying back to roost at dusk. They feed in groups, while one individual watches for danger from a nearby perch. They shelter in trees during the hottest times of the day. Their flight pattern is typically a series of quick, shallow wing beats with gliding in between. They fly to and from feeding grounds at considerable height, to swoop down in wide, sweeping circles. They are noisy birds and screeching is their main method of communication. They raise and spread their striking crests when danger threatens or during mating.
Sulfur-crested cockatoos are mainly herbivores in the wild, and will feed on the ground as well as in trees. They eat mainly seeds, nuts, blossoms, fruits, insects and insect larvae. Newly planted and ripening grains are another source. In captivity they are mainly fed fresh fruits, vegetables, nuts, seeds, pellets, legumes and grains.
These birds are monogamous, forming bonds that last a long time. In the north they breed from May until September, whereas in the south the season is from August to January. The usual nest is high in a tree hollow, most often near water. They breed once a year, when 2 to 3 white eggs are laid, to be incubated by both parents, for 27 to 30 days. Both parents feed the chicks. At approximately 70 days the chicks are ready to leave the nest but will stay with the parents, and family units will stay together indefinitely. Reproductive maturity for both male and female is around 3 to 4 years old.
Sulphur-crested cockatoos are a very popular as a cage-bird, but many of them escape to become pests in city areas. They are vulnerable to a viral disease where they lose their feathers and their bills grow misshapen. They can be shot or poisoned because they are a pest for farmers.
According to IUCN, the global population size has not been quantified. In some parts of Australia, they can be very abundant, and may cause damage to cereal and fruit crops. Consequently, they can be shot or poisoned as pests. The introduced population in New Zealand may number fewer than 1000 birds. In Singapore, it is believed there are between 500 and 2000 birds. The population in Taiwan has been estimated at less than 100 breeding pairs. The ICUN lists the Sulphur-crested cockatoo as a "Least Concern, with a decreasing population trend due to ongoing habitat destruction.
The cockatoos' role in their ecosystems is not well documented. They may help with seed dispersal.