The spectacular but endangered California condor is the largest bird in North America. These superb gliders travel widely to feed on carcasses of deer, pigs, cattle, sea lions, whales, and other animals. Pairs nest in caves high on cliff faces. The population fell to just 22 birds in the 1980s, but there are now some 230 free-flying birds in California, Arizona, and Baja California with another 160 in captivity. Lead poisoning remains a severe threat to their long-term prospects. Read their story here.
Excerpt
The California condor, Gymnogyps californianus (Figure 1), is one of the largest flying birds in the world. When it soars, the wings spread more than nine feet from tip to tip. Condors may weigh more than 20 pounds. The male Andean condor of South America is even larger than our California condor. Both are endangered species.
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 (Figure 2). 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.
There are few feathers on the head and neck of the condor (Figure 3) and 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.
Contrary to the usual among true birds of prey, the female is slightly smaller than the male. Overall length can range from 43 to 55 in. and wingspan from 8.2 to 9.8 ft. Their weight can range from 15 to 31 lb., (Side Bar A) with estimations of average weight ranging from 18 to 20 lb. Wingspans of up to 11 ft. have been reported but no wingspan over 10 ft. has been verified. Most measurements are from birds raised in captivity, so determining if there are any major differences in measurements between wild and captive condors is difficult (Side Bar B).
California condors have the largest wingspan of any North American bird (Figure 4). They are surpassed in both body length and weight only by the trumpeter swan and the introduced mute swan. The American white pelican and whooping crane also have longer bodies than the condor. Condors are so large they can be mistaken for a small, distant airplane, which possibly occurs more often than they are mistaken for other species of bird.
The middle toe of the foot of the California condor is greatly elongated and the hind one is only slightly developed (Figure 5). The talons of all the toes are straight and blunt, and are thus more adapted to walking than gripping. This is more similar to their supposed relatives, the storks, than to birds of prey and Old World vultures, which use their feet as weapons or organs of prehension.
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