The white cockatoo is around 46 cm (18 in) long, and weighs about 400 g (14 oz) for small females and up to 800 g (28 oz) for big males. The male white cockatoo usually has a broader head and a bigger beak than the female. They have brown or black eyes and a dark grey beak. When mature some female white cockatoos can have reddish/brown irises, while the irises of the adult male are dark brown or black.