The former comprises all known species of true cockatoo while the latter includes only the cockatiel. Cockatoos are distinguished from other parrots by the prominent, erectile crests on their heads and their strongly curved bills. They range in size from 30 centimetres to 60 centimetres and are among the longest living of all parrot species. There are numerous reports of cockatoos living to 80 years and sometimes to 100 years. However, the oldest cockatoo with an accurately known age was only 53 years old.
Most cockatoos feed only on plant material.
Cockatoos inhabit forest, grassland and rainforest and are usually seen in large, noisy groups, sometimes numbering in the hundreds. Cockatoos keep the same mate for life. In the absence of a cockatoo mate, they will bond closely and socialise with their human owners. In such cases they become very attached to the human owner and separation can often result in sickness or death to the cockatoo. During breeding, both parent cockatoos share the role of incubating the eggs, although the female plays a larger part.