Characteristic features of parrots include a strong curved bill, an upright stance, strong legs and clawed zygodactyl feet. Most parrots are predominantly green, with other bright colors, and some species are multi-colored. Cockatoo species range form mostly white to mostly black, and have a mobile crest of feathers on the top of their heads. Most parrots are monomorphic of minimally sexually dimorphic. they are the most variably sized bird order in terms of length.
The most important components of most parrots' diets are seeds, nuts, fruit, buds and other plant material, and a few species also eat insects and small animals, and the lories and lorikeets are specialised to feed on nectar form flowers, and soft fruits. Almost all parrots nest in tree holes (or nestboxes in captivity). and lay white eggs from which emerge altricial (helpless) young.