Old World vultures hunt carcasses by eye, not nose
The vultures of Europe, Asia and Africa belong to the hawk and eagle family Accipitridae, not to the lineage of American condors. They lack that group's keen sense of smell, and they probably come from two unrelated branches of the family that each evolved into carrion eaters, independently arriving at the same bald-headed look.
Most authorities recognise two clades. Gypaetinae, containing the bearded vulture, the palm-nut vulture and the Egyptian vulture, seems allied to honey-buzzard-type hawks, while Aegypiinae, including the griffons and the lappet-faced vulture, sits close to the true eagles and may even belong inside them. Despite the name, these birds ranged across North America until the end of the Pleistocene about 11,000 years ago.
They locate carcasses purely by sight. The bare or downy head was long explained as a way to keep feathers clean of blood, but newer research points to temperature control, shedding heat so the face does not overheat; some vultures actually hunt live prey.
More than half the species are now rated vulnerable, endangered or critically endangered. In India and Pakistan numbers fell by up to 99 percent after farmers dosed working livestock with the painkiller diclofenac; vultures feeding on treated carcasses die of kidney failure and gout, and only a small share of tainted carcasses is enough to do the damage. Meloxicam is a safe substitute, and Pakistan and Nepal banned veterinary diclofenac, but India's 2006 ban was still being flouted in 2007. Because vultures feed in large crowds, a single poisoned carcass can kill many.
In Africa poisoning and trade cause about 90 percent of losses. Ivory poachers lace elephant remains deliberately, since circling birds betray a kill to rangers, and in Kruger National Park white-backed vultures could vanish within 60 years. Herders poisoning lions and other predators kill vultures too. Nearly 30 percent of recorded deaths are linked to muthi, traditional medicine in which dried heads are thought to bring foresight or lottery luck, and power lines account for about 9 percent.
Source: Old World vulture
