Turkey Vultures: Nature's Cleanup Crew

Turkey vultures. They're hard to admire. After all, they eat carrion, defend their nests by regurgitating, and excrete on themselves. However, they perform an important yet thankless function. Turkey vultures help to rid the landscape of road kill and other carcasses. It's even reflected in their scientific name, Cathartes aura---Cathartes from the Greek word katharsis meaning to purge or cleanse.

Turkey vultures are common from southern Canada, throughout most of the United States and into South America. Northern birds are migratory, leaving colder areas in September and October for warmer climates. Some turkey vultures migrate in flocks while others join up with more of their kind en route south.

The turkey vulture is a brownish-black bird with two-tone black wings and a naked red head. A large bird, the turkey vulture has a wingspan of nearly 6 feet. Once in the air, the turkey vulture is quite graceful, soaring for hours on updrafts and rising columns of warm air called thermals. In flight, a turkey vulture holds its wings extended into a V-shape, lightly rocking from side to side. Turkey vultures are able to stay within the thermals by flying in tight circles.

Their diet consists almost entirely of carrion from fresh to putrid, although they will occasionally feed on decaying vegetation, insects or fish. Efficient scavengers, turkey vultures quickly dispose of carcasses. They can consume the bodies of animals that died of illness or infection without being adversely affected. They are most likely to be found soaring over open or semi-open country, including fields, lightly wooded areas, deserts and foothills.

Turkey vultures often congregate together in areas known as roosts. They will rest in the largest trees or sit in trees to sun themselves---late risers, turkey vultures wait for sun to warm them. They pose with wings slightly drooped, known as a spread wing posture. This helps dry their wings and regulate their body temperature. Wing spreading in the morning absorbs solar energy, passively raising temperature to daytime level.

Since they have no syrinx or voice box, turkey vultures cannot sing like other birds. Instead, they hiss, grunt and huff.

Now to some of their unsavory habits. Yes, if threatened or disturbed they will throw up. There are several explanations for why they do this. Some believe that predators will consume the regurgitated material and leave the turkey vulture alone, or it may serve to distract a potential predator. Most believe, however, that it is simply a defensive reaction caused by fright. Turkey vultures have one more bad habit: They excrete down their legs. There are two theories for why they do this: One is that because their excrement contains so much ammonium it helps to kill bacteria; another theory is that they do it to help cool themselves.

Despite these characteristics, they do have redeeming qualities. Pairs are monogamous, and both parents incubate the eggs, as well as feed and care for the young. Nest sites consist of little or no nest at all, and eggs are laid on debris inside a hollow tree or log, in crevices on cliffs, and in caves, dense thickets or old buildings.

Usually two whitish eggs, blotched with brown and lavender, are laid. Incubation lasts 34-41 days, and young are born with a coat of down and eyes open but must be fed by parents by regurgitation. If the nest is disturbed, parents will protect it by violent vomiting. Immature turkey vultures look similar to their parents except they have black heads and beaks. The young are able to fly at about 9-10 weeks old, and their beaks turn to adult white or ivory by the age of four.

Though they may not be on your list of favorite birds, turkey vultures do help to recycle carcasses quickly. With the increase in development, there are undoubtedly more road kills. Scavengers like turkey vultures keep the surrounding environment clear of unsightly and decaying animal bodies. So, remember that when you see one circling overhead, in the absence of vultures, every day would be like a garbage strike.

Kathryn Reshetiloff is employed by the Fish and Wildlife Service, U.S. Department of the Interior. Illustration by Robert Savannah, U.S. Fish & Wildlife Service.


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