Twenty-two crested parrots define Australasian skies
Cockatoos are twenty-two Cacatuidae species native to Australasia, crest-flashing cousins of true parrots. Plumage runs white, grey, or black with color accents. They flock over seeds and roots, nest monogamously in hollows, and enter slang as lookouts for illegal games.
Their range runs from the Philippines and eastern Indonesia through New Guinea and the Solomon Islands to Australia. Molecular studies show the New Zealand parrots branched off first from the parrot line, cockatoos next, and only then the true parrots that spread across the Southern Hemisphere. Within the family, the cockatiel sits somewhere near the base, its exact position unresolved; the five big black Calyptorhynchus species form one branch, while twelve white Cacatua species plus the galah, gang-gang and palm cockatoo form the other.
Most weigh 300 to 1,200 grams and measure 30 to 60 centimetres, though the slim cockatiel is only 80 to 100 grams. All have a movable crest, raised on landing or when excited, and they lack the feather structure that produces the blues and greens of other parrots, which is why their plumage runs to white, grey, black and pink. Galahs have been clocked at 70 kilometres an hour. The bill stays sharp because the birds rasp their jaws together at rest; when husking seeds, the lower jaw presses while a muscular tongue holds the seed against the upper jaw.
They eat seeds, tubers, corms, fruit, flowers and insects, often in big ground-feeding flocks, and pairs are monogamous, nesting in tree hollows. Clearing mature trees robs some species of nest sites, while others thrive as farm pests, and illegal trapping for the pet trade depletes wild numbers.
The only truly ancient fossil is a corella-like Cacatua from Riversleigh, Australia, 16 to 23 million years old. The word reached English in the 1600s from Dutch kaketoe, from Malay kakatua, and Australians still call a gambling lookout a cockatoo.
Source: Cockatoo
