Turkey Vultures


Vultures are large birds of prey closely related to hawks and eagles.
They are divided into New World vultures and Old World vultures, both belonging
to the order Falconiformes. The New World vultures, in the family Cathartidae,
consist of seven species in five genera. Among the New World vultures include
the Cathartes aura, also known as the Turkey Vulture.
Scientists say that turkey vultures are shy, inoffensive birds. Some
researchers have discovered that the bird is very helpful to the environment.
Its habit of cleaning up decaying and diseased carcasses makes it a sanitary
engineer par excellence, while its keen sense of smell has been pressed into
service to find wasteful and dangerous gas leaks. And the vulture’s unique
knack for conserving energy has intrigued scientists for years.
Although the turkey vulture has a large, turkeylike body and sporty red
head, it is not even distantly related to the turkey. Instead, turkey vultures-
along with their cousins in the United States, the black vulture of the South
and East, and the nearly extinct California condor-belong to a group of raptors
called New World vultures. Chromosome analysis shows that the New World
vultures are actually more closely related to storks than to the vultures of
Europe, Asia, and Africa.
Turkey vultures are remarkably successful birds. They range everywhere
from parts of Canada and much of the United States to South America. At home in
deserts, prairies and woodlands, they have even settled close to people in a
number of urban and suburban areas.
Observed in flight, the turkey vulture appears black with the underside
of its wings grayish or silvery, giving the birds a two-toned appearance. They
characteristically hold their wings in a slight V, or dihedral, thus aiding
identification. On rare occasions, they hold their wings flat and eagle-like
which, if seen at a great distance, may cause the birds to resemble eagles. In
flight, the turkey vulture holds it’s naked head, crimson-red as adults and
grayish-black as immatures, downward in contrast to eagles, which hold their
heads forward.
The tail of the turkey vulture extends far beyond the rear edge of its
wings. They typically rock or tilt from side to side while gliding or soaring
on updrafts or circling overhead. Their occasional wingbeats are powerful and
labored. Turkey vultures are large birds with wingspreads of about six feet.
Their wings are long, moderatly wide, and have strongly slotted tips. Typically,
the wings are held slightly above a horizontal plane when the bird is aloft.
This forms a characteristic dihedral which is very useful in making correct
field identification. Although turkey vultures use thermals, they are more
dependant upon updrafts when migrating along mountains. The birds use the air
currents skillfully and seldom exert much energy by flapping their wings.
Much of the credit for the bird’s success, scientists say, belongs to
its efficient use of energy. Turkey vultures are marvels of energy conservation.
It seems a turkey vulture’s whole life is spent trying to conserve every little
calorie it gets. If there’s some small way it can save burning its own body fat
and tissue, it will. Like an energy-conscious homeowner, a vulture turns down
its thermostat at night. During the night, a turkey vulture’s body temperature
drops a few degrees. The result is a savings in the vulture’s energy bank. To
warm up again in the morning without burning much fuel, the prehistoric-looking
bird spreads its wings and soaks up all the sun it can.
Another trick performed by the turkey vulture is a behavior called
urohidrosis. Like all birds, the turkey vulture has no sweat glands. To cool
itself during hot spells, it frequently defecates on its own legs. The slurry
of white uric acid in the feces contains mositure that cools by evaporating.
The behavior, shared by other vultures and storks, is more efficient that
sweating since it requires no boost in metabolism.
The turkey vulture’s most basic ploy for saving energy is simply staying
put. If the weather is bad for flying, they can and will sit at their roost for
days. Since their metabolism is low compared to many other birds, fasting seems
to bother them little, if at all. This ability to go without food comes in
handy for another reason. The animal’s food supply is extremely unpredictable.
They don’t know where their next meal is coming from.
The birds are well-equipped to get that next meal though. Compared with
the heavier, chunkier black vultures, turkey vultures have light bodies and long,
broad wings which provide excellent lift. They don’t use or lose a lot of
energy landing and taking off, so they’re able to exploit small