Encyclopedia
The
Turkey Vulture is the most common
vulture in the
Americas. Despite the similar name and appearance, this species is unrelated to the Old World vultures in the family Accipitridae, which also includes
eagles,
hawks,
kites and harriers. The American species is a
New World vulture in the family Cathartidae.
This bird got its common name because the adult's bald red head was thought to resemble that of a male
Wild Turkey.
Appearance
The typical adult bird is an average 76 cm long with a 185 cm wingspan, and weighing 1.4 kg . Both sexes appear similar with the female being slightly larger. Their body feathers are mostly brownish-black, but the flight feathers on wings appear silvery-gray underneath, contrasting with the darker wing linings. The adult head is small in proportion to it's body, red in color with little to no feathers on it, and has a relatively short, hooked bill that is ivory-colored. The immature bird has a gray head with a black beak tip.
Flight
While soaring, they hold their wings in a
V-shape and often tip "drunkenly" from side to side, sometimes causing the gray flight feathers to look silvery as they catch the light. They flap their wings very infrequently, and often take advantage of rising thermals to keep them soaring. The flight style, small-headed and narrow-winged silhouette, and underwing pattern make this bird easy to identify at great distances.
These birds soar over open areas, watching for dead animals or other scavengers at work. Unlike most other birds, in addition to eyesight, the Turkey Vulture uses its sense of smell to locate
carrion. It will often fly low to the ground to pick up the scent of mercaptan, a gas produced by the beginnings of decay of dead animals. The part of its brain responsible for processing smells is particularly large, compared to other birds. Its heightened ability to detect odors allows it to find dead animals below a forest canopy.
Voice
Turkey vultures, like most other vultures, have very few vocalization capabilities. They can only utter hisses and grunts. They usually hiss when they feel threatened. Grunts are commonly heard from hungry young, and adults in courtship
Food
Feeds primarily on a wide variety of
carrion, from small mammals to dead cows, preferring those recently dead . Can also feed on plant matter, shoreline vegetation, pumpkin, crops, live insects, and other invertebrates. They also prefer the meat of herbivorous animals, avoiding that of dogs and other carnivores. Turkey Vultures can often be seen along roadsides, cleaning up roadkill, or near rivers, feasting on washed-up fish, another of their favorite foods.
Habitat
The Turkey Vulture is found in open and semi-open areas throughout
the Americas from southern
Canada to
Cape Horn. It is a permanent resident in the southern
United States but northern birds may
migrate as far south as
South America.
The nesting site is in a protected location: on a cliff, directly on ground in caves, crevices, mammal burrows, inside a hollow tree, in a thicket, or in abandoned buildings. There is little or no construction of a nest. Females lay two eggs, cream-colored with brown spots around large end. Both parents incubate, and the young hatch at around 40 days. The adults regurgitate food for them and care for them for 10 to 11 weeks. If the young are approached in the nest, they defend themselves by hissing and regurgitating. The age of the young at first flight is about 9-10 weeks.
Often, small to large groups of these birds spend the night at communal roosts. Favoured locations may be reused for many years.
Range
Summer RangeBreeds from southern Canada throughout the United States and southward through southern South America and the Caribbean. Local or absent in Great Plains.
Winter RangeWinters from northern California, Mexican border, eastern Texas, southern Missouri, and southern New York southward throughout the southeastern United States
Behaviour
The Turkey Vulture is gentle and non-aggressive. Turkey Vultures roost in large community groups, breaking away to forage independently during the day.
Turkey Vultures are often seen standing in a spread-winged stance. This is called the "horaltic pose." The stance is believed to serve multiple functions: Drying the wings, Warming the body, and Baking off bacteria.
The turkey vulture has few natural predators. Its primary form of defense is vomiting. The birds do not "projectile vomit," as many would claim. They simply cough up a lump of semi-digested meat. This foul smelling substance deters most creatures intent on raiding a vulture nest. It will also sting if the offending animal is close enough to get the vomit in its face or eyes.
In some cases, the vulture must rid its crop of a heavy, undigested meal in order to lift off and flee from a potential predator. In this case, the regurgitated material has not yet been digested. Most predators will give up pursuit of the vulture in favor of this free edible offering.
Like its
stork relatives, the Turkey Vulture often defecates on its own legs, using the evaporation of the water in the feces and/or urine to cool itself down, a process know as urohydrosis. Also, due to the nature of their diets, vulture excreta has a high uric acid content that acts as a sanitizer and kills any bacteria the bird picks up while traipsing on its food. This allows them to be very tolerant of microbial toxins, such as botulism, and certain synthetic poisons that have been used to kill coyotes and ground squirrels.
Protection status
In the
United States, this species receives special legal protections under the
Migratory Bird Treaty Act of 1918. Overall North American populations have increased over the last few decades and the breeding range has expanded northward.
Interesting Facts
The Turkey Vulture usually forages alone, unlike its smaller, more social relative, the
American Black Vulture. Although one Turkey Vulture can dominate a single Black Vulture at a carcass, usually such a large number of Black Vultures appear that they can overwhelm a solitary Turkey Vulture and take most of the food.
Circling vultures do not necessarily indicate the presence of a carcass. Circling vultures may be gaining altitude for long flights, searching for food, or playing.
A group of vultures is called a "Venue". Vultures circling in the air are a "Kettle"
Vultures have excellent eyesight, but, like all other birds, they have poor vision in the dark.
DNA evidence shows that turkey vultures and other new world vultures are more closely related to storks than they are to old world vultures. The similarities are due to convergent evolution.
This bird is said to be the most damaging bird to
aircraft in
birdstrikes as rated by the
Smithsonian Institution's Feather Identification Laboratory. As of July's 2006 planned launch of the
Space Shuttle Discovery STS-121 mission,
NASA is taking actions to prevent any vultures and other birds from striking the shuttle during liftoff, as it can possibly present certain threat of damaging the vehicle.
Images
References
- ffrench, Birds of Trinidad and Tobago ISBN 0-7136-6759-1
Database entry includes justification for why this species is of least concern
- Hilty, Birds of Venezuela, ISBN 0-7136-6418-5
- Stiles and Skutch, A guide to the birds of Costa Rica ISBN 0-0814-9600-4
- Kirk, D. A., and M. J. Mossman. 1998. Turkey Vulture . In The Birds of North America, No. 339 . The Birds of North America, Inc., Philadelphia, PA.
External links
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- on the Internet Bird Collection
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