Some vultures have nine-foot wingspans and can weigh as much as a small dog. Because they are so large, they can’t beat their wings quickly to create the lift that allows most birds to get off the ground. Instead, vultures make use of hot air currents called thermals. Each morning, as the earth is heated by the sun, columns of warm air rise up invisibly into the
sky, and vultures hitch a ride. They circle and soar over the land below, moving from one thermal ‘bubble’ to another. Amazingly, it is possible for them to float for hours without ever having to beat their wings.
Atop their thermals, vultures carefully glide in circles, watching for their next meal. Their eyesight may be more than eight times sharper than a human’s, and this lets them keep an eye on animals and other vultures as distant as two miles away. They watch for animals below that are dead or dying, because vultures eat only carrion, and do not kill their own food. When they are lucky enough to spy a dead animal, or notice that other vultures in the distance are quickly descending to a find, they dive to become part of a large, noisy group of birds that can reduce a large animal to bones in two or three hours.
Vultures are not particular about what they eat, so long as it is meat. They do not kill their prey, waiting instead to find the carcass of an animal that has died of natural causes or been killed by some other animal. The absence of feathers on the head and neck allows a vulture to thrust its head inside a carcass without damaging or dirtying its feathers. Often a vulture will eat so much at one time that it cannot fly again until it has had time to digest.
Some vultures — the condors — are thought to form mated pairs that last for a long time, possibly for life. These couples rear their young together, usually one or two chicks a year.
The turkey vulture occurs farther north than other vultures: it ranges from Canada to Patagonia, migrating south in winter to avoid the coldest weather. Vultures are found on most continents, but are limited to areas where warm air thermals are common.
Most vultures are not endangered, and continue to thrive in adequate numbers. Some, like the California Condor, are extremely endangered, and only survive thanks to human intervention. Pesticides are one of the major threats to birds of prey: eating animals that died by poison or carcasses loaded with lead buckshot can be lethal. Pesiticides washed into streams and rivers also work their way up the food chain to damage vulture populations. If people can reduce this threat and maintain adequate habitat for vultures, they should thrive for years to come.