The yellow-headed caracara (Milvago chimachima) is a bird of prey in the family Falconidae, the falcons and caracaras. It is found in Nicaragua, Costa Rica, Panama, every mainland South American country except Chile, and on Aruba, Bonaire, Curaçao, and Trinidad and Tobago. Taxonomy and systematics Louis Jean Pierre Vieillot described the yellow-headed caracara as Polyborus chimachima, putting it in the same genus as the crested caracaras. In 1824, German naturalist Johann Baptist von Spix created the genus Milvago for this species and the closely related chimango caracara. The taxonomy of the caracaras has not been settled. The American Ornithological Society and the International Ornithological Committee place the yellow-headed and chimango caracaras in genus Milvago. BirdLife International's Handbook of the Birds of the World places the yellow-headed caracara alone in Milvago and the chimango caracara and four others in genus Phalcoboenus. The Clements taxonomy places the yellow-headed, chimango, and four other caracaras in genus Daptrius. The other systems place only the black caracara in Daptrius. The worldwide systems agree that the yellow-headed caracara has two subspecies, the nominate M. c. chimachima and M. c. cordata. A larger and stouter paleosubspecies, M. c. readei, occurred in Florida and possibly elsewhere some tens of thousand years ago, during the Late Pleistocene. Description The yellow-headed caracara is long. Males weigh and females . Their wingspan is . The sexes' plumages are alike. Adults of the nominate subspecies have buff to creamy yellowish white head, neck, and underparts with a thin dark streak through the eye. Their back and wings are blackish brown with a whitish patch at the base of the primaries that shows in flight. Their uppertail coverts and tail are buff with dusky bars and the tail has a black band near the end. Their iris is reddish brown surrounded by bare bright yellow skin and their legs and feet are pea green. Immature birds have browner upperparts than adults and their underparts have brown streaks. Subspecies M. c. cordata is a darker buff on the head and underparts than the nominate and has narrower bars on the tail. Distribution and habitat Subspecies M. c. cordata is found in southwestern Nicaragua, western Costa Rica, and most of Panama, and in mainland South America from Colombia east through Venezuela and the Guianas, south through Ecuador and Peru east of the Andes, and across Brazil north of the Amazon River. The Nicaragua records are