Vulture

Vultures comprise two groups of carrioneating birds. They are useful because they eat carrion, which otherwise might decay and endanger the health of other animals. The twenty-one vulture species inhabit temperate to tropical regions of the Americas, Europe, Asia, and Africa. All vultures exhibit similar eating habits, behavior, and appearance, including bare heads and necks. Many also have somber-colored feathers. Vultures of Europe, Asia, and Africa (Old World vultures) arise from eaglelike birds. Vultures of the Americas (NewWorld vultures), similar in appearance to OldWorld vultures, are anatomically related more closely to storks.

Some Characteristics of Vultures
Vultures have bare heads and necks and hooked bills. Carrion is their main food, and on some occasions they attack newborn or wounded animals. Most hunt by long-distance soaring to scavenge with their keen sight. New World vultures differ from OldWorld vultures in their lack of the ability to vocalize. Six species compose New World vultures. Three live in North America: turkey vultures of the southern United States and northern Mexico; black vultures of the southwestern United States and Central America; endangered California condors; king vultures; Andean condors; and yellow-headed turkey vultures of South America. There are fourteen Old World vulture species. Among the most interesting are the cinereous (with a color resembling ashes) vultures of southern Europe, northwest Africa, and Asia; the similar griffon vultures; white (Egyptian) vultures found from the Mediterranean to India; and the bearded vultures (lammergeiers) of Europe, Asia, and Africa. Vultures lack feathers on their heads and necks, which keeps them free of gore fromcarrion. Among New World vultures, several have interesting appearances. Black vultures have black heads and plumage, with white feathers under the wings. King vultures, in contrast, have feathered neck ruffs and yellow, red, white, and blue heads. California condors, the largest North American land birds, average four feet in length, with wingspans up to eleven feet. They have black neck ruffs, bald, orange to yellow heads, and black plumage except for white feathers under wings. Andean condors are similar. South American yellow-headed turkey vultures resemble North American turkey buzzards. Notable among Old World vultures are cinereous vultures, about four feet long with bare, pinkish heads and black feathers. They inhabit Europe, northwest Africa, and Central Asia. Griffon vultures are similar in size and appearance. Egyptian vultures, two feet long, have yellow heads and white feathers except for black wings. They inhabit Mediterranean areas and are found as far east as India. Bearded vultures (lammergeiers) are especially interesting. They live on Asian, African, and European mountains. They have tan plumage on the chest and stomach and dark brown wing and tail plumage. Lammergeiers have red eyes in white heads. Conspicuous black feathers surrounding the eyes end in beardlike tufts and led to the name “bearded.” These vultures average four feet long and weigh up to twenty-four pounds. Their huge wings allow soaring for hours on thermal updrafts. Lammergeiers are unusual in building large, conical nests on or in rock ledges or caves. A mated, monogamous pair uses the nests many times.

Life Cycles of Vultures
Most vultures nest on bare ground underneath mountain overhangs, or in caves. They build no nests, and females lay eggs on bare rock. After hatching, both parents feed the chicks partly digested carrion regurgitated into their mouths. For example, Andean (great) condors live in mountain caves, and females lay one or two greenish-white to bluish-white eggs on the cave floor. Both parents incubate the eggs until they hatch. The scarcity of the California condor is partly due to the fact that it lays only one egg at two- to three-year intervals. Young condors fly in six months, but parents feed them for another eighteen months. Andean condors first mate at seven years old, and at two-year intervals after that. They are monogamous and maylive for forty-five to fifty years. Lammergeiers, as noted, are unusual in building several nests used over and over. The female lays her eggs, incubates them, and feeds chicks with the help of the male.

Marabous: Storks or Vultures?
Marabou storks (marabous) combine stork and vulture anatomy and occur throughout Africa. Adults are five feet tall. They have long, storklike legs and sharp, straight bills. Their heads and necks are vulturelike. Most marabou food is deer, antelope, and zebra carrion. Marabou plumage is gray on the back and wings, with white bellies and ruffs encircling red necks. Most inhabit African wetlands, rivers, and lakes. Pairs build nests in trees or on rocky terrain. Usually, three eggs are laid and incubated by both parents. Chicks hatch during dry season when carrion is plentiful. They stay with their parents for six months. Marabous live for over twenty years. Vultures consume carrion, preventing decay and danger to health. This activity is one of their main ecological functions. Some vultures (such as condors) eat live food, giving them another ecological function, killing injured or weak members of other species. This helps the species that are eaten to select for individuals which enhance long-term survival.