Parrots or Psittacines is an order (namely Psittaciformes) of birds that includes about 353 species. They are usually grouped into two families: the Cacatuidae (cockatoo), and the Psittacidae (true parrots) that do best using parrot food. All members of the order have a characteristic curved beak shape with the upper mandible having slight mobility in the joint with the skull and a generally erect stance. All parrots are zygodactyl, with two toes at the front of each foot and two at the back. Studies with captive birds have given us insight into which birds are the most intelligent. While parrots have the distinction of being able to mimic human speech, studies with the African Grey Parrot have shown that some are able to associate words with their meanings and form simple sentences. Along with crows, ravens, and jays (family Corvidae), parrots are considered the most intelligent of birds. The brain-to body size ratio of psitticines and corvines is actually comparable to that of higher primates. All do best on parrot food. Mazuri Parrot Maintenance is a complete diet for large birds. This pelleted diet is specially formulated for non-breeding birds (young birds after the first molt up to breeding age and for birds kept in non-breeding situations).