Information about New World Vulture

New World vultures
American Black Vultures on a cow carcass American Black Vultures on a cow carcass
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Aves Order: Ciconiiformes Family: Cathartidae Lafresnaye, 1839
Genera
Coragyps Cathartes Gymnogyps Vultur Sarcoramphus

The New World vultures family Cathartidae contains seven species found in warm and temperate areas of the Americas. It includes five vultures and two condors. Except Cathartes, all genera are monotypic.

New World vultures are not closely genetically related to the superficially similar family of Old World vultures, the similarities between the two groups of vultures being due to convergent evolution. They were widespread in both the Old World and North America, during the Neogene.

Vultures are scavenging birds, feeding mostly from carcasses of dead animals. New World vultures have a good sense of smell, but Old World vultures find carcasses exclusively by sight. A particular characteristic of many vultures is a bald head, devoid of feathers.

Description

These birds are generally large, ranging in length from the Lesser Yellow-headed Vulture at 56–61 cm (22–24 inches) up to the California and Andean Condors, both of which can reach 120 centimeters (48 inches) in length and weigh 12 or more kilograms (26 or more pounds). Plumage is predominantly black, or brown, sometimes with white. All species have featherless heads. In some, this skin is brightly colored, and in the King Vulture it is developed into colorful wattles and outgrowths.

All species have long, broad wings and a stiff tail, suitable for soaring. The feet are clawed but weak. No New World vulture has a syrinx (Kemp and Newton 2003), so the voice is limited to infrequent grunts and hisses (Howell and Webb 1995).

The nostrils are not divided by a septum (they are "perforate"), so from the side one can see through the beak (Allaby 1992), as in the Turkey Vulture. Members of Coragyps and Cathartes have a single incomplete row of eyelashes on the upper lid and two rows on the lower lid, while Gymnogyps, Vultur, and Sarcoramphus lack eyelids altogether.^[1]

New World vultures have the unusual habit of urohidrosis, or defecating on their legs to cool them evaporatively. As storks do this too, it is one of the arguments for a close relationship between the two groups (Sibley and Ahlquist 1991).

Diet

All living species of New World vultures and condors are scavengers. Though their diet is overwhelmingly composed of carrion, some species such as the American Black Vulture have been recorded as killing live prey. Other additions to the diet include fruit, eggs, and garbage. Unusually for birds, the Cathartes species have a highly developed sense of smell, which they use to find carrion. Other species such as the American Black Vulture and the King Vulture have weak senses of smell and find food only by sight, sometimes by following Cathartes vultures and other scavengers (Kemp and Newton 2003). The unfeathered heads of these birds are an adaptation for feeding on rotting carrion.

Reproduction

New World vultures and condors do not build nests, instead laying eggs on bare surfaces. The young are altricial and fledge in 2 to 3 months (Howell and Webb 1995).

Species in taxonomic order

• American Black Vulture Coragyps atratus
• Turkey Vulture Cathartes aura
• Lesser Yellow-headed Vulture Cathartes burrovianus
• Greater Yellow-headed Vulture Cathartes melambrotus
• California Condor Gymnogyps californianus
• Andean Condor Vultur gryphus
• King Vulture Sarcoramphus papa

Evolution and systematics

Although New World vultures have many resemblances to Old World vultures (traditionally considered part of the bird-of-prey order Falconiformes, though now often classified in a different order), they are not very closely related. Rather, they resemble Old World vultures because of convergent evolution.

New World vultures were traditionally placed in a family of their own in the Falconiformes (Sibley and Ahlquist 1991). However, in the late 20th century some ornithologists argued that they are more closely related to storks on the basis of karyotype (de Boer 1975), morphological (Ligon 1967), and behavioral (König 1982) data. Thus some authorities place them in the Ciconiiformes with the storks and herons; Sibley and Monroe (1990) even considered them a subfamily of the stork family. This has been criticized as an oversimplification and recently genetic evidence has been presented against it (Cracraft et al. 2004, Gibb et al. 2007). Consequently, there is a recent trend to raise the New World vultures to the rank of an independent order Cathartiformes not closely associated with either birds of prey or storks or herons (Ericson et al. 2006). In 2007 the American Ornithologists' Union's North American checklist moved Cathartidae back into the lead position in Falconiformes (American Ornithologists' Union 2007). The AOU's draft South American checklist calls the Cathartidae incertae sedis (of uncertain position) rather than placing it any order (Remsen et al. 2007).

Extinct species and fossils

A related extinct family were the Teratornithidae or Teratorns, essentially an exclusively (North) American counterpart to the New World vultures - the latter were, in prehistoric times, also present in Europe and possibly even evolved there. The Incredible Teratorn is sometimes called "Giant Condor" because it must have looked similar to the modern bird. They were, however, not very closely related but rather an example of parallel evolution, and the external similarity is less emphasized in recent times due to new information suggesting that the teratorns were more predatory than vultures (Campbell & Tonni 1983).

The fossil history of the Cathartidae is fairly extensive, but nonetheless confusing. Many taxa that may or may not have been New World vultures were considered to be early representatives of the family. There is no unequivocal European record from the Neogene and trying to retrace the evolutionary history of the entire Ciconiiformes sensu Sibley & Ahlquist by means of molecular analysis has proven to be just as equivocal until the mid-2000s.

At any rate, the Cathartidae had a much higher diversity in the Plio-/Pleistocene, rivalling the current diversity of Old World vultures and their relatives in shapes, sizes, and ecological niches. Extinct genera are:

• Diatropornis (Late Eocene/Early Oligocene -? Middle Oligocene of France)
• Phasmagyps (Early Oligocene of WC North America)
• Brasilogyps (Late Oligocene - Early Miocene of Brazil)
• Hadrogyps (Middle Miocene of SW North America)
• Pliogyps (Late Miocene - Late Pliocene of S North America)
• Perugyps (Pisco Late Miocene/Early Pliocene of SC Peru)
• Dryornis (Early - Late? Pliocene of Argentina; may belong to modern genus Vultur)
• Aizenogyps (Late Pliocene of SE North America)
• Breagyps (Late Pleistocene of SW North America)
• Geronogyps (Late Pleistocene of Peru)
• Wingegyps (Late Pleistocene of Brazil)
• Parasarcoramphus

Fossils found in Mongolia (Late Oligocene), Lee Creek Mine, USA (Late Miocene/Early Pliocene), Argentina (Middle Pliocene) and in more recent deposits on Cuba have not been assigned to a genus yet. There is also a number of extinct congeners of the extant species; see the respective genus accounts.

A European genus from the Earliest Neogene that possibly belongs to the New World vultures is Plesiocathartes. On the other hand, the bathornithid Neocathartes was long believed to be a peculiar New World vulture (including charming, but inaccurate reconstructions as a kind of Turkey Vulture on stilts [1]).

References

• Check-list of North American Birds. American Ornithologists' Union (1998–2006). Retrieved on 2007-04-09.
• Allaby, Michael (1992). The Concise Oxford Dictionary of Zoology. Oxford: Oxford University Press, page 348. ISBN 0192860933.
• Avise, J. C.; Nelson, W. S. & Sibley, C. G. (1994) DNA sequence support for a close phylogenetic relationship between some storks and New World vultures. Proc. Natl. Acad. Sci. USA 91(11): 5173-5177. doi:10.1073/pnas.91.11.5173 PDF fulltext. Erratum, PNAS 92(7); 3076 (1995). doi:10.1073/pnas.92.7.3076b (PDF fulltext)
• Campbell, Kenneth E. Jr. & Tonni, E. P. (1983): Size and locomotion in teratorns. Auk 100(2): 390-403 PDF fulltext
• de Boer, L. E. M.(1975): Karyological heterogeneity in the Falconiformes (Aves). Cellular and Molecular Life Sciences 31(10): 1138-1139. doi:10.1007/BF02326755 (HTML abstract)
• Cracraft, J., F. K. Barker, M. Braun, J. Harshman, G. J. Dyke, J. Feinstein, S. Stanley, A. Cibois, P. Schikler, P. Beresford, J. García-Moreno, M. D. Sorenson, T. Yuri, and D. P. Mindell. 2004. Phylogenetic relationships among modern birds (Neornithes): toward an avian tree of life. Pp. 468-489 in Assembling the tree of life (J. Cracraft and M. J. Donoghue, eds.). Oxford University Press, New York. Accessed 2007-04-10.
• Ericson, Per G. P.; Anderson, Cajsa L.; Britton, Tom; Elżanowski, Andrzej; Johansson, Ulf S.; Kallersjö, Mari; Ohlson, Jan I.; Parsons, Thomas J.; Zuccon, Dario & Mayr, Gerald (2006): Diversification of Neoaves: integration of molecular sequence data and fossils. Biology Letters, in press. doi:10.1098/rsbl.2006.0523 PDF preprint Electronic Supplementary Material
• Gibb, G. C., O. Kardailsky, R. T. Kimball, E. L. Braun, and D. Penny. 2007. Mitochondrial genomes and avian phylogeny: complex characters and resolvability without explosive radiations. Molecular Biology Evolution 24: 269–­280. HTML abstract accessed 2007-04-10.
• Howell, Steve N.G., and Sophie Webb (1995). A Guide to the Birds of Mexico and Northern Central America. New York: Oxford University Press, page 174. ISBN 0-19-854012-4.
• Kemp, Alan, and Ian Newton (2003): New World Vultures. In Christopher Perrins, ed., The Firefly Encyclopedia of Birds. Firefly Books, page 146–147. ISBN 1-55297-777-3.
• Ligon, J. D. (1967): Relationships of the cathartid vultures. Occasional Papers of the Museum of Zoology, University of Michigan 651: 1-26.
• Remsen, J. V., Jr., C. D. Cadena, A. Jaramillo, M. Nores, J. F. Pacheco, M. B. Robbins, T. S. Schulenberg, F. G. Stiles, D. F. Stotz, and K. J. Zimmer. [Version 2007-04-05.] A classification of the bird species of South America. American Ornithologists' Union. Accessed 2007-04-10.
• Sibley, Charles G. and Burt L. Monroe. 1990. Distribution and Taxonomy of the Birds of the World. Yale University Press. ISBN 0-300-04969-2. Accessed 2007-04-11.
• Sibley, Charles G., and Jon E. Ahlquist. 1991. Phylogeny and Classification of Birds: A Study in Molecular Evolution. Yale University Press. ISBN 0-300-04085-7. Accessed 2007-04-11.
• Wink, M. (1995): Phylogeny of Old and New World vultures (Aves: Accipitridae and Cathartidae) inferred from nucleotide sequences of the mitochondrial cytochrome b gene. Zeitschrift für Naturforschung 50(11-12): 868-882.

External links

• New World vulture videos on the Internet Bird Collection
• New World Vulture sounds on xeno-canto.org

References