Old World vulture

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, belonging to two separate not closely related groups within the family. Most authorities refer to two major clades: Gypaetinae (Gypaetus, Gypohierax and Neophron) and Aegypiinae (Aegypius, Gyps, Sarcogyps, Torgos, Trigonoceps and possibly Necrosyrtes). 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. Despite the name of the group, "Old World" vultures were widespread in North America until relatively recently, until the end of the Late Pleistocene epoch around 11,000 years ago. == Biology ==

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. Vulture populations are particularly vulnerable because they typically feed in large groups and easily fall victim to mass poisoning events. Threats Diclofenac Diclofenac poisoning 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. Meloxicam (another NSAID) has been found to be harmless to vultures and should prove an acceptable alternative to diclofenac. In Kruger National Park, white-backed vultures will be eradicated in the next 60 years if poisoned carcasses are not detected and neutralized. Eliminating carcass poisoning is challenging because it is far easier to carry out than to regulate. Park officials often lack the training to identify toxic chemicals before it is too late and calling on average community members to turn in perpetrators reports is challenging if financial incentives to do so are insufficient. For those who rely on livestock to make a living, illegal pesticides are often used on fruits, meats, or even the water in a wateringhole in order to eliminate large predators that threaten their livestock. Agricultural poisoning is relatively easy as it does not require specific skills and the poison is cheap with a long shelf life. Vulture heads are believed to provide clairvoyance or good luck like winning the lottery. 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 ==

Conservation efforts would be most effective in large, protected areas because vultures are most populous in those. 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. Proposed strategies to reduce poisoning events include mobile phone numbers to report offenders, campaigns to educate about poisoning risks to humans, and improving response speed to poisoning events. Poison response training would be an important implementation in conservation efforts because this is one of the most prevalent threats to vulture populations. == References ==