Cathartes aura
turkey vulture

Turkey vultures range as far north as the southern border of Canada and as far south as Tierra del Fuego, Chile. Over the past few decades, they have been expanding their geographic range northward. This expansion may be a result of laws and restrictions on hunting this species. (Wallace, 2004)

Turkey vultures occupy a diverse range of habitats. They are found in forested as well as open environments. Turkey vultures can be found anywhere they can effectively find a carrion food supply. They are easily habituated to humans and human development. (Wallace, 2004)

There are six subspecies of turkey vultures: three in North America and three in South and Central America. Cathartes aura septentrionalis is found in the eastern United States and west into Minnesota, Kansas, Oklahoma, and eastern Texas. Cathartes aura meridionalis is located mainly west of C. a. septentrionalis and into Baja California, excluding the lower Colorado River valley. Cathartes aura aura is found in the lower Colorado River valley, including most of Arizona, and in southern New Mexico and Texas. Cathartes aura ruficollis is found from Costa Rica south to northern Argentina and east of the Andes, Cathartes aura jota is found in the highlands of southern Colombia through Argentina, and Cathartes aura falklandica is found west of the Andes from Ecuador and Peru through Chile and on the Falkland Islands. (Palmer, 1988)

Depending on the subspecies, turkey vultures vary from 0.85 to 2 kg and can have a total length between 64 and 81 cm. Sexes do not differ, all have a brownish black plumage with a bare head and neck. The head and neck skin color can vary from pink to bright red. Turkey vultures are commonly mistaken for black vultures. However, they can be distinguished by their grey primary and secondary feathers and their black head and neck color. (Wallace, 2004)

Based on their wing surface to weight ratio, turkey vultures have light wing loading. This makes them more buoyant in air than other vultures and better able to utilize thermals to help them stay in flight with minimal energy usage. (Wallace, 2004)

To start the mating ritual, several birds gather on the ground and begin hopping around in a circle with wings partially spread. In flight a bird might closely follow a potential mate while continuing a ritual of flapping and diving. (Kaufman, 1996)

Adult mated pairs spend much more time with one another than with other vultures. Mating-pair bonds last throughout the breeding season and often all year long. (Rabenold, 1986)

Breeding takes place from March to June in North America. Nest sites are usually found in sheltered areas such as hollow trees or logs, crevices in cliffs, or in old buildings. Little or no nest is actually built in these sites. Their eggs are laid on debris or the flat bottom of the nest site. Eggs are off-white and marked with brown and lavender. Incubation time is typically 30 to 40 days. Young reach the fledging stage at 70 to 80 days old and are independent about a week later. (Kaufman, 1996)

Turkey vulture chicks are altricial. Adults care for them for 70 to 80 days by regurgitating well-digested food several times daily and providing some protection. Both adults care fr the young. If adults are threatened when nesting, they might flee, regurgitate on the intruder, or play dead. (Fergus, 2003)

There is little recorded information on the lifespan of turkey vultures. A banded individual lived up to 16 years and 10 months. One study demonstrated that up to one-fifth of all adult turkey vultures die each year. (Palmer, 1988)

Turkey vultures usually roost in large community groups, but search for food independently during daylight hours. Groups as large as several hundred vultures have been observed to roost together, sometimes including black vultures. Populations in colder areas migrate seasonally to warmer weather. (Fergus, 2003)

Turkey vulture home range sizes depend on the availability of food. They will travel as far as necessary to find carrion. If food becomes scarce in one area, they move to other areas. A study in South Carolina found that in non-agricultural areas, vulture home ranges were approximately twice as large as those found in neighboring residential or agricultural areas. Turkey vultures do not defend territories. (Kelly, et al., 2007; Wallace, 2004)

Like most vultures, turkey vultures lack complexity in vocalizations. Most vocalizations are grunts, hisses, and barking sounds, used mainly for predator deterrence. Visual cues are used in mating rituals and may be used in other forms of communication.

Turkey vultures have a well-developed sense of smell and are one of the only species of birds worldwide that uses smell extensively. They use their keen sense of smell and their vision to locate carcasses. Black vultures take advantage of this, following turkey vultures to carcasses and then excluding them. (Stevenson and Anderson, 1994)

Turkey vulture diets vary depending on their habitat. Vultures living around agriculture feed mainly on the carrion of domestic animals, mostly livestock. They also rely heavily on roadkill in areas of human development. A study in South Carolina found that in non-agricultural areas, their primary source of food was wild carrion. Turkey vultures preferentially feed on smaller carcasses, but will feed on dead animals of any size. They prefer freshly dead carcasses but cannot get through the thick skin of larger animals, so must wait for some decay to enable entering body cavities. To find their food they rely on their keen sense of smell and vision. They are one of the few bird species that has an acute sense of smell. In some cases, turkey vultures have been seen eating rotten fruits and vegetables and occasionally they prey on insects, reptiles, or bird nestlings. Turkey vultures have also been observed eating coyote and domestic animal dung. (Kelly, et al., 2007; Wallace, 2004)

Turkey vulture chicks and eggs are preyed on by mammalian nest predators, such as raccoons. Young and adults are sometimes preyed on by owls. Although turkey vultures have few natural predators, they are known for their defense mechanism of regurgitating semi-digested meat--which deters most predators due to its putrid smell.

Most documented mortality of turkey vultures is caused by human interactions, including collisions with vehicles and structures and entrapment in fencing and leg-hold traps. Problems caused by black vultures are sometimes blamed on turkey vultures by association. Humans sometimes destroy turkey vultures and their roosts. (Lowney, 1999)

In 1994 there was an observation at Isla Espiritu Santo, Baja California, Mexico, of yellow-footed gulls (Larus livens) attacking a turkey vulture that had flown near their breeding colony. (Rodríguez-Estrella, et al., 1995)

Because turkey vultures are major consumer of carrion, they play an important role in biodegradation. (Kaufman, 1996)

Black vultures follow turkey vultures to carcasses and then aggressively out-compete them at the carcass. (Stevenson and Anderson, 1994)

There are multiple parasitic bacteria that have been associated with turkey vultures. In a study in Texas, two ectoparasites from families Cimididae and Hippoboscidae were found to be on some turkey vultures. Another study at the University of California showed that turkey vultures are capable of contracting Chlamydiosis. This was observed in a captive subject at a raptor rehabilitation center in California in 1983. (Fowler, et al., 1990; Wilson and Oliver, Jr., 1978)

Turkey vultures are important as scavengers. They remove dead carcasses, which can pose a health risk to humans and livestock.

Because turkey vultures commonly roost with black vultures where they co-occur, they are sometimes associated with the negative impacts of black vultures. In Virginia, black vultures have been caught killing young livestock and harassing, injuring, or even killing domestic pets. Numerous non-lethal attempts have been made to remove vultures from the area include: deter these roosts by removing carrion, moving expectant cattle to alternate pastures, pyrotechnics to scare off vultures, and monitoring livestock several times a day. These efforts are generally ineffective. Lethal methods of removal are common among farmers to prevent further economic losses. Turkey vultures rarely kill small animals, relying almost exclusively on carrion. (Lowney, 1999)

Turkey vultures are a common species throughout their range. The IUCN lists them as a species of Least Concern.