Black Vulture

Identification

The black vulture is a fairly large scavenger, measuring 56–74 cm (22–29 in) in length, with a 1.33–1.67 m (52–66 in) wingspan. Weight for black vultures from North America and the Andes ranges from 1.6 to 3 kg (3.5 to 6.6 lb) but in the smaller vultures of the tropical lowlands it is 1.18–1.94 kg (2.6–4.3 lb). 50 vultures in Texas were found to average 2.15 kg (4.7 lb) while 119 birds in Venezuela were found to average 1.64 kg (3.6 lb). The extended wing bone measures 38.6–45 cm (15.2–17.7 in), the shortish tail measures 16–21 cm (6.3–8.3 in) and the relatively long tarsus measures 7–8.5 cm (2.8–3.3 in). Its plumage is mainly glossy black. The head and neck are featherless and the skin is dark gray and wrinkled. 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. The legs are grayish white, while the two front toes of the foot are long and have small webs at their bases.<p>The nostrils are not divided by a septum, but rather are perforate; from the side one can see through the beak. 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.<p>A leucistic C. atratus brasiliensis was observed in Piñas, Ecuador in 2005. It had white plumage overall, with only the tarsus and tail as well as some undertail feathers being black. It was not an albino as its skin seemed to have had the normal, dark color and it was part of a flock of some twenty normally plumaged individuals.

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". 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. 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. The common name "vulture" is derived from the Latin word vulturus, which means "tearer" and is a reference to its feeding habits. The species name, ātrātus, means "clothed in black", from the Latin āter 'dull black'.<p>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 Greek corax/κόραξ and gyps/γὺψ for the respective birds.<p>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.<p>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.<p>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), and hence they are no longer recognised.<p>"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.<p>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. It filled a similar ecological niche as the living form but fed on larger animals, and was previously thought to have evolved into it by decreasing in size during the last ice age. 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. 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.<p>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.<p>An additional fossil species from the Late Pleistocene of Cuba, C. seductus, was described in 2020.

Scientific name

Coragyps atratus

Authority

(Bechstein, 1793)

Order

Cathartiformes

Family

Cathartidae

Genus

Coragyps

Range and habitat

The black vulture has a Nearctic and Neotropic distribution. 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. 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. In South America, its range stretches to Peru, central Chile and Uruguay. It also is found as a vagrant on the islands of the Caribbean. It prefers open land interspersed with areas of woods or brush. It is also found in moist lowland forests, shrublands and grasslands, wetlands and swamps, pastures, and heavily degraded former forests. Preferring lowlands, it is rarely seen in mountainous areas. It is usually seen soaring or perched on fence posts or dead trees.

Migration

Complete migrants

Behavior

Migration pattern: Complete migrants.

Conservation

Population trend: rising.

Population trend

rising