The California Condor (Gymnogyps californianus) is a New World vulture, the largest North American land bird. This condor became extinct in the wild in 1987 (all remaining wild individuals were captured) but has been reintroduced to northern Arizona and southern Utah (including the Grand Canyon area and Zion National Park), coastal mountains of central and southern California, and northern Baja California. Although other fossil members are known, it is the only surviving member of the genus Gymnogyps.The adult California Condor is a uniform black with the exception of large triangular patches or bands of white on the underside of the wings. It has gray legs and feet, an ivory-colored bill, a frill of black feathers surrounding the base of the neck, and brownish red eyes. The juvenile is mostly a mottled dark brown with blackish coloration on the head. It has mottled gray instead of white on the underside of its flight feathers. As an adaptation for hygiene, the condor's head and neck have few feathers, which exposes the skin to the sterilizing effects of dehydration and solar ultraviolet light at high altitudes.[citation needed] The skin of the head and neck is capable of flushing noticeably in response to emotional state, a capability that can serve as communication between individuals. The skin color varies from yellowish to a glowing reddish-orange. The birds do not have true syringeal vocalizations. They can make a few hissing or grunting sounds only heard when very close.
From : http://en.wikipedia.org/wiki/California_Condor