Old World vultures are vultures that are found in the Old World, i.e. the continents of Europe, Asia and Africa, and which belong to the family Accipitridae, which also includes eagles, buzzards, kites, and hawks. Old World vultures are not closely related to the superficially similar New World vultures and condors, and do not share that group's good sense of smell. The similarities between the two groups of vultures are due to convergent evolution, rather than a close relationship. They were widespread in both the Old World and North America during the Neogene. Old World vultures are probably a polyphyletic group within Accipitridae, with the palm-nut vulture, Egyptian vulture and bearded vulture separate from the others. Most authorities refer to two major clades: Gypaetinae and Aegypiinae. The former seem to be nested with Perninae hawks, while the latter are closely related and possibly even synonymous with Aquilinae. Within Aegypiinae, Torgos, Aegypius, Sarcogyps and Trigonoceps are particularly closely related and possibly within the same genus. Both Old World and New World vultures are scavenging birds, feeding mostly from carcasses of dead animals. Old World vultures find carcasses exclusively by sight. A particular characteristic of many vultures is a semi-bald head, sometimes without feathers or with just simple down. Historically, it was thought that this was due to feeding habits, as feathers would be glued with decaying flesh and blood. However, more recent studies have shown that it is actually a thermoregulatory adaptation to avoid facial overheating; the presence or absence of complex feathers seems to matter little in feeding habits, as some vultures are quite raptorial.
Species
† = extinct
Population declines, threats, and implications
Population declines
More than half of the Old World vulture species are listed as vulnerable, endangered, or critically endangered by the IUCN Red List. Population declines are caused by a variety of threats that vary by species and region, with most notable declines in Asia due to diclofenac use. As vultures play an important role in ecosystems, their population decline can have cultural, public health, and economic implications for communities. Within Africa, a combination of poisonings and vulture trade account for roughly 90% of the population declines.
Threats
Diclofenac
has caused the vulture population in India and Pakistan to decline by up to 99%, and two or three species of vulture in South Asia are nearing extinction. This has been caused by the practice of medicating working farm animals with diclofenac, which is a non-steroidal anti-inflammatory drug with anti-inflammatory and pain-killing actions. Diclofenac administration keeps animals that are ill or in pain working on the land for longer, but, if the ill animals die, their carcasses contain diclofenac. Farmers leave the dead animals out in the open, relying on vultures to tidy up. Diclofenac present in carcass flesh is eaten by vultures, which are sensitive to diclofenac, and they suffer kidney failure, visceral gout, and death as a result of diclofenac poisoning. Meloxicam has been found to be harmless to vultures and should prove an acceptable alternative to diclofenac. The Government of India banned diclofenac, but over a year later, in 2007, it continued to be sold and remains a problem in other parts of the world.
Other poisonings
Poisoning accounts for a majority of vulture deaths in Africa. Ivorypoacherspoison carcasses with the intent of killing vultures, since vultures circling over a carcass alert authorities to a kill. Vultures are also unintentionally poisoned when they consume carcasses of predators that have been poisoned by livestock farmers.
As vultures play an important role in ecosystems, their population decline can have cultural, public health, and economic implications for communities. The decline in vultures has led to hygiene problems in India as carcasses of dead animals now tend to rot, or be eaten by rats or feral dogs, rather than be consumed by vultures. Rabies among these other scavengers is a major health threat. India has one of the world's highest incidences of rabies. For communities such as the Parsi, who practice sky burials in which human corpses are put on the top of a Tower of Silence, vulture population declines can have serious cultural implications.
Conservation efforts
A project named "Vulture Restaurant" is underway in Nepal in an effort to conserve the dwindling number of vultures. The "restaurant" is an open grassy area where naturally dying, sick, and old cows are fed to the vultures. Organizations across Africa are working to reduce threats to vulture species with efforts to change and create policies to protect species both at the national and international scale.
