Any of three species (genus Apteryx) of chicken-sized, grayish brown ratite birds, found in New Zealand. Their Maori name refers to the male's shrill call. Kiwis have vestigial wings hidden within the plumage; nostrils at the tip (rather than the base) of the long flexible bill; soft, hairlike feathers; and stout, muscular legs. Each of the four toes has a large claw. Kiwis live in forests, where they sleep by day and forage for worms, insects and their larvae, and berries at night. They run swiftly and use their claws in defense when cornered.