The Sulphur-crested Cockatoo (Cacatua galerita) is a relatively large white cockatoo found in wooded habitats in Australia, and New Guinea and some of the islands of Indonesia. They can be locally very numerous, leading to them sometimes being considered pests. A highly intelligent bird, they are well known in aviculture, although they can be demanding pets.
Sulphur-crested cockatoos are 44–55 cm (17.5–21.5 in) long, and the plumage is overall white, while the underwing and tail are tinged yellow. The expressive crest is yellow. The bill is black, the legs are grey, and the eye-ring is whitish. Males typically have almost black eyes, whereas the females have a more red or brown eye, but this requires optimum viewing conditions to be seen. They are often confused with the yellow-crested cockatoo and blue-eyed cockatoos, but since they don't overlap in range, they can be easily identified in the wild.
The differences between the subspecies are subtle. The Mathews cockatoo (C. g. fitzroyi) is similar to the greater sulphur-crested cockatoo (Cacatua galerita galerita) (the nominate race) but lacks the yellow on the ear tufts and has slightly blueish skin around the eye. The Eleonora cockatoo (Cacatua galerita eleonora) is similar to the Mathews cockatoo but is smaller and has broader feathers in the crest, and the Triton cockatoo (Cacatua galerita triton) is similar to the Eleonora cockatoo except it has a smaller bill.
Sulphur-crested cockatoos' distinctive raucous calls can be very loud, which is a result of an adaption in order to travel through the forest environments in which they live, including tropical and subtropical rainforests. These birds are naturally curious, as well as very intelligent. They have adapted very well to European settlement in Australia and live in many urban areas. These birds are very long-lived, and can live upwards of 70 years in captivity, although they only live to about 20–40 years in the wild. They have been known to engage in geophagy, the process of eating clay to detoxify their food. These birds produce a very fine powder to waterproof themselves instead of oil as many other birds do.