Black vulture

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 only extant member 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 eagles, hawks, 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 Template:Convert, 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.<ref>Template:Cite web</ref> 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, especially those of the Cathartes genus which 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.

Taxonomy

The American naturalist William Bartram wrote of the black vulture in his 1791 book Bartram's Travels, calling it Vultur atratus "black vulture" or "carrion crow".<ref>Template:Cite book</ref> Bartram's work has been rejected for nomenclatoríal purposes by the International Commission on Zoological Nomenclature as the author did not consistently use the system of binomial nomenclature.<ref>Template:Cite book</ref> The German ornithologist Johann Matthäus Bechstein formally described the species using the same name in 1793 in his translation of John Latham's A General Synopsis of Birds.<ref>Template:Cite book</ref><ref>Template:Cite book</ref> The common name "vulture" is derived from the Latin word vulturus, which means "tearer" and is a reference to its feeding habits.<ref name="Holloway">Template:Cite book</ref> The species name, ātrātus, means "clothed in black", from the Latin āter 'dull black'.<ref>Template:Cite book</ref>

Black vulture pair feeding on a mule deer head. Plate 106 from The Birds of America by J. J. Audubon.

Vieillot defined the genus Catharista in 1816, listing as its type C. urubu.<ref>Template:Cite book</ref> French naturalist Emmanuel Le Maout placed in its current genus Coragyps (as C. urubu) in 1853.<ref>Template:Citation</ref> Isidore Geoffroy Saint-Hilaire has been listed as the author in the past, but he did not publish any official description.<ref>Template:Cite journal</ref> The genus name means "raven-vulture",<ref name="Taro">Template:Cite web</ref> from a contraction of the Greek corax/κόραξ and gyps/γὺψ for the respective birds.<ref>Template:Cite book</ref>

The American Ornithologists' Union used the name Catharista atrata initially before adopting Vieillot's name (Catharista urubu) in their third edition.<ref>Template:Cite book</ref> By their fourth edition, they had adopted the current name.<ref>Template:Cite book</ref>

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.<ref>Template:Cite journal</ref>

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.<ref name="Blake">Template:Cite book</ref> However, it has been established that the change between the three subspecies is clinal (that is, there is no division between the subspecies),<ref name=hbw>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).</ref> and hence they are no longer recognised.<ref name="ioclist"/>

C. occidentalis fossil

"Black vulture" has been designated the official name by the International Ornithologists' Union (IOC).<ref name="ioclist">Template:Cite web</ref> "American black vulture" is also commonly used,<ref name="hbw" /> 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.<ref>Template:Cite web</ref>

Evolutionary history of Coragyps

From the Early to the Late Pleistocene, a prehistoric species of black vulture, C. occidentalis, known as the Pleistocene black vulture or—somewhat in error—the "western black vulture", occurred across the present species' range. This bird did not differ much from the black vulture of today except in size; it was some 10–15% larger and had a relatively flatter and wider bill.<ref>Template:Cite journal</ref> It filled a similar ecological niche as the living form but fed on larger animals,<ref>Template:Cite journal</ref> and was previously thought to have evolved into it by decreasing in size during the last ice age.<ref>Template:Cite journal</ref><ref name="Steadman">Template:Cite journal</ref> However, a 2022 genetic study found C. occidentalis to be nested within the South American clade of black vultures; C. occidentalis had evolved from the modern black vulture about 400,000 years ago and developed a larger and more robust body size when it colonized high-altitude environments.<ref name=":0">Template:Cite journal</ref> C. occidentalis may have interacted with humans; a subfossil bone of the extinct species was found in a Paleo-Indian to Early Archaic (9000–8000 years BCE) midden at Five Mile Rapids near The Dalles, Oregon.<ref>Template:Cite journal</ref>

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.<ref>Template:Cite journal</ref> 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.<ref>Template:Cite journal</ref> 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.<ref name="Steadman"/><ref name=":0" />

An additional fossil species from the Late Pleistocene of Cuba, C. seductus, was described in 2020.<ref>Template:Cite journal</ref>

Description

Adult and juvenile, Hueston Woods State Park, Ohio

The black vulture is a fairly large scavenger, measuring Template:Convert in length, with a Template:Convert wingspan.<ref>Template:Cite web</ref> Weight for black vultures from North America and the Andes ranges from Template:Convert but in the smaller vultures of the tropical lowlands it is Template:Convert.<ref>Black Vulture, Life History, All About Birds – Cornell Lab of Ornithology. allaboutbirds.org</ref><ref name = "Ferguson"/> Fifty vultures in Texas were found to average Template:Convert while 119 birds in Venezuela were found to average Template:Convert.<ref name = "CRC">CRC Handbook of Avian Body Masses, 2nd Edition by John B. Dunning Jr. (Editor). CRC Press (2008), Template:ISBN.</ref> The extended wing bone measures Template:Convert, the shortish tail measures Template:Convert and the relatively long tarsus measures Template:Convert.<ref name = "Ferguson"/> Its plumage is mainly glossy black. The head and neck are featherless, and the skin is dark gray and wrinkled.<ref name="Terres"/> The iris of the eye is brown and has a single incomplete row of eyelashes on the upper lid and two rows on the lower lid.<ref name="Pterylosis">Template:Cite journal</ref> The legs are grayish-white,<ref name="Peterson"/> while the two front toes of the foot are long and have small webs at their bases.<ref name="Feduccia"/>

The nostrils are not divided by a septum, but rather are perforate; one can see through the beak from the side.<ref>Template:Cite book</ref> 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.<ref name="Terres">Template:Cite book</ref>

A leucistic C. atratus brasiliensis was observed in Piñas, Ecuador in 2005. It had white plumage overall, with only the tarsus 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.<ref>Template:Cite journal</ref>

Distribution and habitat

The black vulture has a Nearctic and Neotropic distribution.<ref>Template:Cite book</ref> Its range includes the mid-Atlantic States, the southernmost regions of the Midwestern United States, the southern United States, Mexico, Central America, and most of South America.<ref name="Chihuahua Desert">Template:Cite web</ref> In the 21st century, the black vulture's range has expanded northward farther into the Midwest and northeastern United States.<ref>Template:Cite journal</ref> It is usually a permanent resident throughout its range, although birds at the extreme north of its range may migrate short distances and others across their range may undergo local movements in unfavourable conditions.<ref>Buckley, N. J. (1999). Black Vulture (Coragyps atratus). In The Birds of North America, No. 411 (A. Poole and F. Gill, eds.). The Birds of North America, Inc., Philadelphia, PA.</ref> In South America, its range stretches to Peru, central Chile, Uruguay<ref name="Hilty">Template:Cite book</ref> and Brazil. It also is found as a vagrant on the islands of the Caribbean.<ref name="iucn status 19 November 2021" /> It prefers open land interspersed with areas of woods or brush.<ref name="Harrison"/> It is also found in moist lowland forests, shrublands and grasslands, wetlands and swamps, pastures, and heavily degraded former forests.<ref name="iucn status 19 November 2021" /> Preferring lowlands, it is rarely seen in mountainous areas. It is usually seen soaring or perched on fence posts or dead trees.<ref name="Peterson">Template:Cite book</ref>

Black vulture flying over the Parque de las Leyendas in Lima Peru

Ecology and behavior

The black vulture soars high while searching for food, holding its wings horizontally when gliding. It flaps in short bursts, followed by short periods of gliding.<ref name="Robbins">Template:Cite book</ref> Its flight is less efficient than that of other vultures, as the wings are not as long, forming a smaller wing area.<ref name="Fergus">Template:Cite book</ref> In comparison with the turkey vulture, the black vulture flaps its wings more frequently during flight. It is known to regurgitate when approached or disturbed, which assists in predator deterrence and taking flight by decreasing its takeoff weight. Like all New World vultures, the black vulture often defecates on its legs, using the evaporation of the water in the feces and/or urine to cool itself, a process known as urohidrosis.<ref name="Feduccia">Template:Cite book</ref> It cools the blood vessels in the unfeathered tarsi and feet, and causes white uric acid to streak the legs. Because it lacks a syrinx, the black vulture, like other New World vultures, has very few vocalization capabilities.<ref name="Feduccia"/> It is generally silent, but can make hisses and grunts when agitated or while feeding. The black vulture is gregarious and roosts in large groups.<ref name="CornellLab"/> In areas where their ranges overlap, the black vulture will roost on the bare branches of dead trees alongside groups of turkey vultures.<ref name="Fergus"/> The black vulture generally forages in groups; a flock of black vultures can easily drive a rival turkey vulture, which is generally solitary while foraging, from a carcass.<ref name="CornellLab">Template:Cite web</ref>

Like the turkey vulture, this vulture is often seen standing in a spread-winged stance.<ref name="Terres"/> 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 storks.<ref name="snyder"/>

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.<ref name="u257">Template:Cite web</ref>

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  C. a. brasiliensis
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  C. a. brasiliensis, Copan, Honduras
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  A pair from Panama, in Soberania National Park
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  C. a. sunbathing in the morning and eating carrion, in Brazil

Breeding

Egg, Collection Museum Wiesbaden

Hatchlings

The timing of black vultures' breeding season varies with the latitude at which they live. In the United States, birds in Florida begin breeding as early as January, while those in Ohio generally do not start before March.<ref name = "Ferguson"/> In South America, Argentinian and Chilean birds begin egg-laying as early as September, while those further north on the continent typically wait until October. Some in South America breed even later than that—black vultures in Trinidad typically do not start until November, for example, and those in Ecuador may wait until February.<ref name = "Ferguson"/> Pairs are formed following a courtship ritual which is performed on the ground: several males circle a female with their wings partially open as they strut and bob their heads.<ref name="Terres"/> They sometimes perform courtship flights, diving or chasing each other over their chosen nest site.<ref name = "Ferguson"/>

The black vulture lays its eggs on the ground in a wooded area, a hollow log, or some other cavity, seldom more than Template:Convert above the ground.<ref name="Terres"/> 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.<ref name="Harrison"/> Clutch size is generally two eggs, though this can vary from one to three. The egg is oval and, on average, measures Template:Convert. The smooth, gray-green, bluish, or white shell is variably blotched or spotted with lavender or pale brown around the larger end.<ref name="Harrison">Template:Cite book</ref> Both parents incubate the eggs, which hatch after 28 to 41 days.<ref name="Harrison"/> Upon hatching, the young are covered with a buffy down, unlike turkey vulture chicks which are white.<ref name="Readers"/> 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.<ref name="Fergus"/> Predation of black vultures is relatively unlikely, though eggs and nestlings are readily eaten if found by mammalian predators such as raccoons, coatis and foxes. Due to its aggressiveness and size, few predators can threaten the fully-grown vulture. However, various eagles 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).<ref name = "Ferguson"/><ref>Template:Cite journal</ref><ref>Template:Cite journal</ref>

Feeding

Black vultures observe a morning catch of fish in Puerto López , Ecuador.

The black vulture eats mainly carrion in natural settings.<ref name="Readers">Template:Cite book</ref> In areas populated by humans, it may scavenge at garbage dumps for refuse, offal, and other discarded edible waste, but also takes eggs, fruit (both ripe and rotting), fish, dung and ripe/decomposing plant material and can kill or injure newborn or incapacitated mammals.<ref>Template:Cite web</ref><ref>Template:Cite journal</ref> Like other vultures, it plays an important role in the ecosystem by disposing of carrion which would otherwise be a breeding ground for disease.<ref name="cotton"/> The black vulture locates food either by sight or by following New World vultures of the genus Cathartes to carcasses.<ref name="cotton">Template:Cite journal</ref> These vultures—the turkey vulture, the lesser yellow-headed vulture, and the greater yellow-headed vulture—forage by detecting the scent of ethyl mercaptan, a gas produced by the beginnings of decay in dead animals.<ref name="Dietland">Template:Cite book</ref> Their heightened ability to detect odors allows them to search for carrion below the forest canopy.<ref name="snyder">Template:Cite book</ref> The black vulture is aggressive when feeding and may chase the slightly larger turkey vulture from carcasses.<ref name="Readers"/>

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.<ref>Template:Cite web</ref><ref name = "Ferguson"/> 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.<ref>Template:Cite web</ref>

Black vultures have sometimes been observed removing and eating ticks from resting capybaras and Baird's tapir (Tapirus bairdii).<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> These vultures are known to kill baby herons and seabirds on nesting colonies, and feed on domestic ducks, small birds, skunks, opossums, other small mammals, lizards, small snakes, young turtles and insects.<ref>Template:Cite web</ref><ref name = "Ferguson">Template:Cite book </ref> 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.<ref>Template:Cite journal</ref>

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  Feeding on a wood stork
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  A flock on a horse carcass
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  Six vultures on a wild hog carcass in Florida

Legal protections

The black vulture receives special legal protections under the Migratory Bird Treaty Act of 1918 in the United States,<ref name="FWS">Template:Cite web</ref> by the Convention for the Protection of Migratory Birds in Canada,<ref name="cornell2">Template:Cite web</ref> and by the Convention for the Protection of Migratory Birds and Game Mammals in Mexico.<ref name="cornell2"/> In the United States it is illegal to take, kill, or possess black vultures without a permit and violation of the law is punishable by a fine of up to US$15,000 and imprisonment of up to six months.<ref name="cornell">Template:Cite web</ref> It is listed as a species of Least Concern by the IUCN Red List. Populations appear to remain stable, and it has not reached the threshold of inclusion as a threatened species, which requires a decline of more than 30% in ten years or three generations.<ref name="iucn status 19 November 2021" />

Relationship with humans

On a sign in Florida.

The black vulture is considered a threat by cattle ranchers due to its predation on newborn cattle.<ref>Template:Cite web</ref><ref>Template:Cite journal</ref> However, because predation events are rarely directly witnessed, and vultures quickly flock to animal carcasses, it is unclear whether the majority of reported livestock deaths are actually attributable to vultures.<ref>Template:Cite web</ref> As a defense, the vultures also "regurgitate a reeking and corrosive vomit."<ref>Template:Cite web</ref>

The bird can be a threat to the safety of aerial traffic, especially when it congregates in large numbers in the vicinity of garbage dumps<ref>Pereira, José Felipe Monteiro (2008) Aves e Pássaros Comuns do Rio de Janeiro, Rio de Janeiro, Technical Books, Template:ISBN, p. 35</ref>—as is the case in the Rio de Janeiro Tom Jobim International Airport.<ref>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 Template:Webarchive (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</ref> Between 1990 - 2024, black vultures have been involved in 382 collisions with civil aircraft in the United States.<ref>Template:Cite journal</ref>

In popular culture

The black vulture appears in a variety of Maya hieroglyphics in Mayan codices. It is normally connected with either death or as a bird of prey. The vulture's glyph is often shown attacking humans. This species lacks the religious connections that the king vulture has. While some of the glyphs clearly show the black vulture's open nostril and hooked beak, some are assumed to be this species because they are vulture-like but lack the king vulture's knob and are painted black.<ref name="Maya">Template:Cite book</ref>

Black vultures are an important cultural symbol in Lima, Peru.<ref name="guardian1">Template:Cite news</ref><ref name="elperuano2">Template:Cite web</ref>

This vulture has appeared on two stamps: those of Suriname in 1990 and Nicaragua in 1994.<ref name="Stamp">Template:Cite web</ref>

External links

• Template:Inaturalist taxon
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• Photography showing the skeletal structure of the black vulture
• Live Streaming 24/7 Video of 2013 Nesting Pair of black vultures