Cathartes auraturkey vulture

Geographic Range

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)

Habitat

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)

Physical Description

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)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    0.85 to 2.00 kg
    1.87 to 4.41 lb
  • Range length
    64 to 81 cm
    25.20 to 31.89 in
  • Range wingspan
    170 to 183 cm
    66.93 to 72.05 in

Reproduction

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)

  • Breeding interval
    Turkey vultures breed once yearly.
  • Breeding season
    Breeding occurs from March to June in North America.
  • Range eggs per season
    1 to 3
  • Average eggs per season
    2
    AnAge
  • Range time to hatching
    30 to 40 days
  • Range fledging age
    70 to 80 days
  • Range time to independence
    80 to 90 days

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)

  • Parental Investment
  • altricial
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • male
      • female
  • pre-weaning/fledging
    • provisioning
      • male
      • female
    • protecting
      • male
      • female
  • pre-independence
    • provisioning
      • male
      • female
    • protecting
      • male
      • female

Lifespan/Longevity

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)

  • Range lifespan
    Status: wild
    17 (high) years
  • Average lifespan
    Status: wild
    10 years
  • Average lifespan
    Status: wild
    202 months
    Bird Banding Laboratory

Behavior

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)

Home Range

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)

Communication and Perception

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)

Food Habits

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)

  • Animal Foods
  • birds
  • reptiles
  • carrion
  • insects
  • Other Foods
  • dung

Predation

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)

Ecosystem Roles

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)

Commensal/Parasitic Species

Economic Importance for Humans: Positive

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

Economic Importance for Humans: Negative

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)

Conservation Status

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

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Adam Farmer (author), Radford University, Karen Francl (editor, instructor), Radford University.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

Neotropical

living in the southern part of the New World. In other words, Central and South America.

World Map

acoustic

uses sound to communicate

agricultural

living in landscapes dominated by human agriculture.

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

biodegradation

helps break down and decompose dead plants and/or animals

carnivore

an animal that mainly eats meat

carrion

flesh of dead animals.

chaparral

Found in coastal areas between 30 and 40 degrees latitude, in areas with a Mediterranean climate. Vegetation is dominated by stands of dense, spiny shrubs with tough (hard or waxy) evergreen leaves. May be maintained by periodic fire. In South America it includes the scrub ecotone between forest and paramo.

chemical

uses smells or other chemicals to communicate

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.

diurnal
  1. active during the day, 2. lasting for one day.
endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

estuarine

an area where a freshwater river meets the ocean and tidal influences result in fluctuations in salinity.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

migratory

makes seasonal movements between breeding and wintering grounds

monogamous

Having one mate at a time.

motile

having the capacity to move from one place to another.

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nomadic

generally wanders from place to place, usually within a well-defined range.

oviparous

reproduction in which eggs are released by the female; development of offspring occurs outside the mother's body.

riparian

Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).

scavenger

an animal that mainly eats dead animals

scrub forest

scrub forests develop in areas that experience dry seasons.

seasonal breeding

breeding is confined to a particular season

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

social

associates with others of its species; forms social groups.

suburban

living in residential areas on the outskirts of large cities or towns.

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

tropical

the region of the earth that surrounds the equator, from 23.5 degrees north to 23.5 degrees south.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5? N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

tundra

A terrestrial biome with low, shrubby or mat-like vegetation found at extremely high latitudes or elevations, near the limit of plant growth. Soils usually subject to permafrost. Plant diversity is typically low and the growing season is short.

urban

living in cities and large towns, landscapes dominated by human structures and activity.

visual

uses sight to communicate

References

2001. Vultures. Gale Encyclopedia of Science. Thomson Gale.

Buckley, N. 1996. Food finding and the influence of information, local enhancement, and commercial roosting on foraging success of North American vultures. The Auk, 113.n2: 473-489.

Buckley, N. 1998. Interspecific competition between vultures for preferred roost positions. Wilson Bulletin, 110.n1: 122-126.

DeVault, T., B. Reinhart, L. Brisbin, O. Rhodes. 2004. Home ranges of sympatric Black and Turkey Vultures in South Carolina.. The Condor, 106.3: 706-710.

Estrella, R. 1994. Group size and flight altitude of Turkey Vultures in two habitats in Mexico.. Wilson Bulletin, 106.n4: 749-752.

Fergus, C. 2003. Wildlife of Virginia and Maryland. Mechanicsburg, PA: Stackpole Books.

Fowler, M., T. Schulz, A. Ardans, B. Reynolds, D. Behymer. 1990. Chlamydiosis in Captive Raptors. Avian Diseases, 34(3): 657-662.

Kaufman, K. 1996. Lives of North American Birds. New York, NY: Houghton Mifflin Field Guides.

Kelly, N., D. Sparks, T. DeVault, O. Rhodes. 2007. Diet of Black and Turkey vultures in a forested landscape.. The Wilson Journal of Ornithology, 119:2: 267-271.

Lowney, M. 1999. Damage by black and turkey vultures in Virginia, 1990-1996. Wildlife Society Bullein: Vol. 2, 27(3): 715-719.

Mandel, J., K. Bildstein. 2007. Turkey Vultures use anthropogenic thermals to extend their daily activity period.. The Wilson Journal of Ornithology, 119.1: 102-106.

Milanich, J. 1997. Archaeology of Northern Florida, A.D. 200-900 : The McKeithen Weeden Island Culture. Florida: Gainesville University Press.

Palmer, R. 1988. Handbook of North American Birds, Volume 4. New Haven and London: Yale University Press.

Rabenold, P. 1986. Family Associations in Communally Roosting Black Vultures. The Auk, 103(1): 32-41.

Rodríguez-Estrella, R., J. Donázar, F. Hiraldo. 1995. Yellow-Footed Gulls Attack Turkey Vultures on Isla Espiritu Santo, Baja California, Mexico. Colonial Waterbirds, 18(1): 100-101.

Seamans, T. 2004. Response of roosting turkey vultures to a vulture effigy. The Ohio Journal of Science, 104.5: 136-139.

Stevenson, H., B. Anderson. 1994. Birdlife of Florida. Florida: Gainesville University Press.

Wallace, M. 2004. New World vultures. Pp. 275-285 in M Hutchins, D Thoney, M McDade, eds. Grzimek's Animal Life Encyclopedia, Vol. 8, 2 Edition. Detroit: Gale.

Wilson, N., G. Oliver, Jr.. 1978. Noteworthy Records of Two Ectoparasites (Cimididae and Hippoboscidae) from the Turkey Vulture in Texas. The Southwestern Naturalist, 23(2): 305-307.