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The black vulture ( Coragyps atratus), also known as the American black vulture, Mexican vulture, zopilote, urubu, or gallinazo, is a bird in the New World vulture family whose range extends from the southeastern United States to Peru, Central Chile and Uruguay in South America, and common throughout Brazil where it can be seen in large scavenging groups. Although a common and widespread species, it has a somewhat more restricted distribution than its compatriot, the turkey vulture, which breeds well into Canada and all the way south to Tierra del Fuego. It is the Monotypic taxon of the genus Coragyps, which is in the family Cathartidae. Despite the similar name and appearance, this species is not closely related to the Eurasian black vulture, an Old World vulture, of the family Accipitridae (which includes raptors like the , , kites, and harriers). For ease of locating animal corpses (their primary source of sustenance), black vultures tend to inhabit relatively open areas with scattered trees, such as chaparral, in addition to subtropical forested areas and parts of the Brazilian pantanal.
With a wingspan of , the black vulture is an imposing bird, though relatively small for a vulture, let alone a raptor. It has black plumage, a featherless, grayish-black head and neck, and a short, hooked beak. These features are all evolutionary adaptations to life as a scavenger; their black plumage stays visibly cleaner than that of a lighter-colored bird, the bare head is designed for easily digging inside animal carcasses, and the hooked beak is built for stripping the bodies clean of meat. The absence of head feathers helps the birds stay clean and remain (more or less) free of animal blood and bodily fluids, which could become problematic for the vultures and attract parasites; most vultures are known to bathe after eating, provided there is a water source. This water source can be natural or man-made, such as a stream or a livestock water tank.
The black vulture is a scavenger and feeds on carrion, but will also eat eggs, small reptiles, or small newborn animals (livestock such as cattle, or deer, rodents, rabbits, etc.), albeit very rarely. They will also opportunistically prey on extremely weakened, sick, elderly, or otherwise vulnerable animals. In areas populated by humans, it also scavenges at dumpster sites and garbage dumps. It finds its meals by using its keen eyesight or following other (New World) vultures, which all possess a keen sense of smell. Lacking a syrinx—the vocal organ of birds—its only vocalizations are grunts or low hisses. It lays its eggs in caves, in cliffside rock crevasses, dead and hollow trees, or, in the absence of predators, on the bare ground, generally raising two chicks each year. The parents feed their young by regurgitation from their crop, an additional digestive organ unique to birds, used for storing excess food; their "infant formula", of sorts, is thus called "crop milk". In the United States, the vulture receives legal protection under the Migratory Bird Treaty Act of 1918. This vulture also appeared in Mayan codices.
Vieillot defined the genus Catharista in 1816, listing as its type C. urubu. French naturalist Emmanuel Le Maout placed in its current genus Coragyps (as C. urubu) in 1853. Isidore Geoffroy Saint-Hilaire has been listed as the author in the past, but he did not publish any official description. The genus name means "raven-vulture", from a contraction of the Ancient Greek corax/κόραξ and gyps/γὺψ for the respective birds.
The American Ornithologists' Union used the name Catharista atrata initially before adopting Vieillot's name ( Catharista urubu) in their third edition. By their fourth edition, they had adopted the current name.
The black vulture is basal (the earliest offshoot) to a lineage that gave rise to the turkey vulture and greater and lesser yellow-headed vultures, diverging around 12 million years ago.
Martin Lichtenstein described C. a. foetens, the Andean black vulture, in 1817, and Charles Lucien Bonaparte described C. a. brasiliensis, from Central and South America, in 1850 on the basis of smaller size and minor plumage differences. However, it has been established that the change between the three subspecies is clinal (that is, there is no division between the subspecies),Houston, D., Kirwan, G.M. & Boesman, P. (2017). American Black Vulture ( Coragyps atratus). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/52943 on October 21, 2017). and hence they are no longer recognised.
"Black vulture" has been designated the official name by the International Ornithologists' Union (IOC). "American black vulture" is also commonly used, and in 2007 the South American Classification Committee (SACC) of the American Ornithological Society unsuccessfully proposed it to be the official name of the species.
Fossil (or subfossil) black vultures cannot necessarily be attributed to the Pleistocene or the recent species without further information: the same size variation found in the living bird was also present in its larger prehistoric relative. Thus, in 1968, Hildegarde Howard separated the Mexican birds as C. occidentalis mexicanus as opposed to the birds from locations farther north (such as Rancho La Brea), which constituted the nominate subspecies C. o. occidentalis. The southern birds were of the same size as present-day northern black vultures and can only be distinguished by their somewhat stouter tarsometatarsus and the flatter and wider bills, and even then only with any certainty if the location where the fossils were found is known. As the Pleistocene and current black vultures form an evolutionary continuum rather than splitting into two or more lineages, some include the Pleistocene taxa in C. atratus, which is further affirmed by phylogenetic studies indicating that it forms a clade within the South American C. atratus.
An additional fossil species from the Late Pleistocene of Cuba, C. seductus, was described in 2020.
The nostrils are not divided by a Nasal septum, but rather are perforate; one can see through the beak from the side. The wings are broad but relatively short. The bases of the primary feathers are white, producing a white patch on the underside of the wing's edge, which is visible in flight. The tail is short and square, barely reaching past the edge of the folded wings.
A leucistic C. atratus brasiliensis was observed in Piñas, Ecuador in 2005. It had white plumage overall, with only the tarsometatarsus and tail and some black undertail feathers. It was not an albino as its skin seemed to have a normal, dark color, and it was part of a flock of some twenty normally plumaged individuals.
Like the turkey vulture, this vulture is often seen standing in a spread-winged stance. The stance is believed to serve multiple functions: drying the wings, warming the body, and baking off bacteria. This same behavior is displayed by other New World vultures, Old World vultures, and .
Black vultures in Northern California have been observed snipping the umbilical cords of newborn sea lions and feeding on the placenta, an example of clever planning.
The black vulture lays its eggs on the ground in a wooded area, a hollow log, or some other cavity, seldom more than above the ground. While it generally does not use any nesting materials, it may decorate the area around the nest with bits of brightly colored plastic, shards of glass, or metal items such as bottle caps. Clutch size is generally two eggs, though this can vary from one to three. The egg is oval and, on average, measures . The smooth, gray-green, bluish, or white shell is variably blotched or spotted with lavender or pale brown around the larger end. Both parents avian incubation the eggs, which hatch after 28 to 41 days. Upon hatching, the young are covered with a buffy down, unlike turkey vulture chicks which are white. Both parents feed the nestlings, regurgitating food at the nest site. The young remain in the nest for two months, and after 75 to 80 days, they can fly skillfully. Predation of black vultures is relatively unlikely, though eggs and nestlings are readily eaten if found by mammalian predators such as , and . Due to its aggressiveness and size, few predators can threaten the fully-grown vulture. However, various may kill vultures in conflicts, and even the ornate hawk-eagle, a slightly smaller bird than the vulture, has preyed on adult black vultures, as well as the two eagles native to North America (north of Mexico).
The black vulture also occasionally feeds on livestock or deer. It is the only species of New World vulture which preys on cattle. It occasionally harasses cows giving birth, but primarily preys on newborn calves, lambs, and piglets. In its first few weeks, a calf will allow vultures to approach it. The vultures swarm the calf in a group and then peck at the calf's eyes, nose, or tongue. The calf then goes into shock and is killed by the vultures.
Black vultures have sometimes been observed removing and eating ticks from resting and Baird's tapir ( Tapirus bairdii). These vultures are known to kill baby and on nesting colonies, and feed on domestic , small birds, , , other small mammals, , small , young and . Like other birds with scavenging habits, the black vulture presents resistance to pathogenic microorganisms and their toxins. Many mechanisms may explain this resistance. Anti-microbial agents may be secreted by the liver or gastric epithelium, or produced by microorganisms of the normal microbiota of the species.
The bird can be a threat to the safety of aerial traffic, especially when it congregates in large numbers in the vicinity of garbage dumpsPereira, José Felipe Monteiro (2008) Aves e Pássaros Comuns do Rio de Janeiro, Rio de Janeiro, Technical Books, , p. 35—as is the case in the Rio de Janeiro Tom Jobim International Airport.Netzel, Christian and de Sá, Marcello Espinola Paraguassú (2004) Estudo preliminar sobre a problemática das aves para a segurança do aeroporto internacional Tom Jobim e o aterro sanitário de Gramacho ( Preliminary study on the threat posed by birds in the Gramacho landfill to the safety of the Tom Jobim International Airport), FGV Environmental Management course monograph, (in Portuguese). resol.com.br
The black vulture can be held in captivity, though the Migratory Bird Treaty Act only allows this in the case of animals which are injured or unable to return to the wild.
Black vultures are an important cultural symbol in Lima, Peru.
This vulture has appeared on two stamps: those of Suriname in 1990 and Nicaragua in 1994.
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