Cathartidae

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Cathartidae
Black vultures.jpg
Black vultures
Coragyps atratus
Scientific classification
Kingdom Information
Domain Eukaryota
Kingdom Animalia
Subkingdom Bilateria
Phylum Information
Phylum Chordata
Sub-phylum Vertebrata
Infraphylum Gnathostomata
Class Information
Superclass Tetrapoda
Class Aves
Sub-class Neornithes
Order Information
Order Cathartiformes
Family Information
Family Cathartidae
Population statistics

Cathartidae is a family of birds found in the Americas, and referred to as New World vultures. The seven species range in size from the black vulture to the condors of California and the Andean Mountains, which are among the largest living flying birds.

Range and habitat

New-world vultures are found throughout North and South America, ranging roughly from extreme southern Canada south to Tierra Del Fuego, with the turkey vulture (Cathartes aura) inhabiting that entire range. New-world vultures live in almost all habitats of their distribution area; in contrast to the old-world vultures, which inhabit open landscapes, New World vultures occur in forests and closed bush lands. Both the turkey vulture and the black vulture (Coragyps atratus) have extended their ranges in recent years, taking advantage of human food waste areas (fish markets, dumps, etc.) as well as road-killed animals. At the opposite end the California condor (Gymnogyps californianus) has been restricted in its own range in the southwestern United States; once at the brink of extinction, the condor is making a slow comeback, and with human help has been reintroduced to parts of its historical range in northwestern Arizona and Baja California in Mexico.

Description

New-world vultures are 25-52 inches in length, and reach a wing span of 53 to 125 inches; their body weight is from 1.8 to 24 pounds. Their plumage is especially dark or black, and in small species there is no gender dimorphism, either in size or shape. In the king vulture (Sarcoramphus papa) and the California condor, the males are about 10% larger than the females. Male Andean condors (Vultur gryphus) are some 25% larger than females; they also differ in the black plumage (the females are dark brown), white neck ruffles, and a fleshy crest on their heads. Adult king vultures, by contrast, are predominantly white, with a head boldly painted in blue, red and yellow colors.

The New World vultures differ from the Old World vultures by the absence of a nasal septum wall and the well-developed sense of smell; these vultures can locate a carcass from several miles away by scent alone, allowing them to take advantage of forested ranges that would normally hide a carcass from Old World vultures which use sight.

Species

  • Genus Cathartes
Greater yellow-headed vulture, Cathartes melambrotus
Lesser yellow-headed vulture, Cathartes burrovianus
Turkey vulture, Cathartes aura
  • Genus Coragyps
Black vulture, Coragyps atratus
  • Genus Gymnogyps
California condor, Gymnogyps californianus
  • Genus Sarcoramphus
King vulture, Sarcoramphus papa
  • Genus Vultur
Andean condor, Vultur gryphus

Diet

New-world vultures are primarily scavengers, but turkey and black vultures also kill defenseless prey, especially small or very young animals, such as lizards or young birds in the nest, or sea turtles just after hatching. They have been accused of attacking newborn lambs and calves, but it is more likely that they consume the afterbirth material. Both species also eat insects, berries and other fruits and manure of larger mammals.

Reproduction

The reproductive behavior of most of the New World vultures is very little known. No species nests in colonies. The two yellow-headed turkey vultures and the king vulture have only been observed a few times or less. The remaining birds have been observed; they do not build nests, but lay their eggs directly on the rocks, in large tree cavities and in tree stumps. The two condors nest on inaccessible rocky promontories in the mountains.

The two condor species lay only a single egg, while black and turkey vultures lay usually two. The eggs are whitish; that of the turkey vulture, which uses more open breeding grounds, spotted. The breeding duration ranges from 40 days with the smaller species and up to 55 days with the condors. The young have a fine down coat, which is white with the condors, the king vulture and the turkey vulture, and brown with the black vulture. The turkey vultures visit their chicks just a few minutes a day for feeding, and the food is brought in the crop to be regurgitated for the chicks. Young condors are only fledged at three months' age, but remain with their parents for a month. The rearing of a single chick in the two condor species takes more than twelve months, which is probably the cause of condors breeding every other year.

Small world vulture species are likely to be sexually mature at three years. Captive condors begin breeding activities only at the age of six. The California condor is probably monogamous, and it is thought that the remaining species are monogamous as well.

Taxonomy controversy

The New World Vultures were initially assigned to the birds of prey (Falconiformes) in the traditional sense, even though Thomas Huxley remarked in 1876 that they were different from all other birds of prey. For more than a hundred years it was known that they share some characteristics with the storks (Ciconiidae); these include in particular the bone structure, the skull anatomy and the arrangement of some muscles. Like storks, they provide cooling by moistening the legs with excretions. In the late twentieth century, molecular biology methods finally opened new possibilities for investigating relationships. Following their new bird system based on DNA hybridization, Charles Gald Sibley and Jon Edward Ahlquist arranged the New World vultures to a subfamily within Ciconiiformes, the family containing storks.[1] However, the Sibley-Ahlquist taxonomy did not find any general recognition, and the New World vultures were left as an independent family within the Ciconiiformes.

In the 1990s, DNA hybridization was replaced by DNA sequencing, which allows the direct comparison of DNA from the nucleus (ncDNA) or the mitochondria (mtDNA). Corresponding investigations first showed that the New World vultures were not related to the storks.[2] The South American Classification Committee (SACC) of the American Ornithologists' Union divided the New World Vultures from the storks.[3] A subsequent analysis revealed a position of the New World Vulture as the base taxon of a clade that contains all groups traditionally considered as birds of prey, with the exception of falcons.[4] The SACC then introduced the New World vultures into their own monotypical order - Cathartiformes - due to its relatively uncertain sister-group relationship with the other predatory birds.[5]

According to the latest results, the International Ornithological Congress (IOC), however, once again grouped the new-world vultures with most groups traditionally classified as birds of prey; Falconidae are no longer included. Since the taxon, which has the scientific name "Falconiformes", has to include its type Falco (falcons), this newly defined group of carnivorous birds has received the name Accipitriformes.[6][7]

References

  1. Charles Sibley, Jon Ahlquist (1990): Phylogeny and classification of birds. Yale University Press, New Haven, Connecticut
  2. G. P. Ericson, Cajsa L. Anderson, Tom Britton, Andrzej Elzanowski, Ulf S. Johansson, Mari Källersjö, Jan I. Ohlson, Thomas J. Parsons, Dario Zuccon, Gerald Mayr: Diversification of Neoaves: integration of molecular sequence data and fossils. Biology Letters, Bd. 2, Nr. 4, 2006, S. 543–547
  3. Proposal (#241) to South American Classification Committee Remove Cathartidae from the Ciconiiformes, August 2006
  4. S.J. Hackett, R.T. Kimball, S. Reddy, R.C.K. Bowie, E.L. Braun, M.J. Braun, J.L. Chojnowski, W.A. Cox, K.-L. Han, J. Harshman, C. Huddleston, B.D. Marks, K.J. Miglia, W.S. Moore, F.H. Sheldon, D.W. Steadman, C.C. Witt and T. Yuri: A Phylogenomic Study of Birds Reveals Their Evolutionary History. Science. Bd. 320 (Nr. 5884), 2008, S. 1763–1768
  5. Proposal (#361) to South American Classification Committee Place Cathartidae in their own order, Juni 2008
  6. Frank Gill and Minturn Wright: BIRDS OF THE WORLD Recommended English Names. Princeton University Press, 2006
  7. https://web.archive.org/web/20131205171210/http://www.worldbirdnames.org/n-raptors.html