Chionididae (sheathbills; class Aves, order Charadriiformes) A family of white, pigeon-like birds that have short, stout legs and unwebbed feet. The stout bill is black, or yellow and black, and covered by a horny sheath. Chionidids have bare and wattled cheeks. Their wings have sharp carpal spurs. They are gregarious and mainly terrestrial, omnivorous, and holenesting in crevices and burrows. There are two species, found on sub-Antarctic Atlantic and Indian Ocean islands.

sheathbills See CHIONIDIDAE.