The Black Vulture (Coragyps atratus) is a New World vulture distributed throughout North and South America. The black vulture is 60 cm to 68 cm in length and weighs between 1.6 kg to 2.2 kg. The average wingspan for the species is about 137 cm to 150 cm. The species is sexually monomorphic and the plumage is black (Buckley, 1999).
Black vultures belong to a grouping of birds known as Falconiformes. Falconiformes are characterized as having a short, hooked beak. Additionally, they have strong feet with long claws and an opposable hind toe, which are used to grasp and manipulate prey. They are diurnal and characterized as strong flyers. Most falconiformes are carnivorous and consume either living or dead animals (Feduccia, 1996). |
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The diet of black vultures consists mostly of carrion, decaying animal flesh, typically from large mammalian carcasses. Although black vultures are scavengers, they are not capable of locating food sources on their own. The species has a reduced olfactory system and therefore cannot use olfactory cues to locate carcasses. The black vulture typically locates food by following or looking for Turkey vultures, which can find food sources through olfaction. Additionally, black vultures are incapable of opening carcasses and require another scavenger to do so before they can feed on the carrion. Once a black vulture has joined a turkey vulture at a carcass, the black vulture often forces the turkey vulture away from the food source (Buckley, 1999).
In addition to eating carrion, black vultures sometimes consume live prey. They often eat maggots from a carcass or kill domestic farm animals, especially newborns and young. A group of black vultures is capable of attacking and killing large, adult animals as well (Buckley, 1999).
Black vultures are efficient gliders, an adaptation needed for scanning large territories in search of an unpredictable food source (Buckley, 1999). Black vultures use a unique form thermoregulation known as urohidrosis. In urohidrosis an individual excretes urine onto its hindlimbs and is able to cool its body temperature through the evaporation of the liquid off its skin (Feduccia, 1996).
Although the black vulture forages in open habitats, they roost and nest in wooded areas. Nests are found in a variety of places such as caves, hollow logs, stumps, tree trunks, thickets, brush piles, crevices between rocks, and even abandoned buildings. However, black vultures do not construct nests and instead deposit eggs directly on the nesting site. Clutch size is typically two eggs and the incubation period typically lasts 38 to 39 days (Buckley, 1999).
Black vultures are monogamous and mate for life. A mate is replaced only after the death of one individual. Both parents incubate eggs using a system of 24 hour shifts and parents feed their young up to eight months after fledging (Buckley, 1999).
Additional Information on the Skull
Click on the thumbnails below for labeled images of the skull in standard anatomical views.
Literature
Arad, Z., U. Midtgard, and M. H. Bernstein. 1989. Thermoregulation in turkey vultures: vascular anatomy, arteriovenous heat exchange and behavior. Condor 91:505-514.
Baumel, J. J., A. S. King, J. E. Breazile, H. E. Evans, and J. C. Vanden Berge (eds.). 1993. Handbook of Avian Anatomy: Nomina Anatomica Avium, Second Edition. Publication of the Nuttall Ornithological Club, number 23. Nuttall Ornithological Club, Cambridge, Massachusetts, 779 pp.
Feduccia, A. 1996. Origin and Evolution of Birds. Yale University Press, New Haven, CT. pp 420.
Harrison, C. J. O. 1981. A new cathartid vulture, Paracathartes howardae, ng. nsp. from the lower Eocene of Wyoming, USA. Tertiary Research, Special Paper, 5:7-10.
Koenig, C. 1982. The taxonomic status of Cathartidae. Journal für Ornithologie 123:259-268.
Lowney, M. S. 1999. Damage by black and turkey vultures in Virginia, 1990-1996. Wildlife Society Bulletin 27:715-719.
Buckley, N. J. 1999. Coragyps atratus. The Birds of North America: Life Histories for the 21st Century 411:1-23
Rabenold, P. P. 1987. Recruitment to food in black vultures: evidence for following from communal roosts. Animal Behaviour 35:1775-1785.
Rosser, B. W. C., and J. C. George. 1986. Slow muscle fibers in the pectoralis of the turkey vulture, Cathartes aura, an adaptation for soaring flight. Zoologischer Anzeiger 217:252-258.
Salas-Auvert, R., and A. Viloria. 1997. Early description of the black vulture on the American continent. Auk 114:513.
Stewart, P. A. 1979. Behavioral interactions and niche separation in black vultures, Coragyps atratus, and turkey vultures, Cathartes aura. Living Bird 17:79-84.
Links
Information and images of Coragyps atratus on the Animal Diversity Web (Univ. of Michigan Museum of Zoology).
Coragyps atratus on the USGS Patuxent Bird Indentification InfoCenter.
Video of C. atratus in Venezuela on the Internet Bird Collection (IBC) site.
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