The term "vulture" refers to sizable birds of prey that hail from both the New World and the Old World. Roughly 21 species of vultures exist. New and Old World vultures are not near kin to each other, but they have a lot in common—notably an intense attraction to animal carcasses.
Vulture Diet Staples
Vultures are famed scavenging birds. The bulk of their diet is made up of carrion—the remains of previously killed animals. Although vultures generally don't kill their own meals, there are a few exceptions. They sometimes go after animals feeble from injury, or defenseless youngsters. They sometimes even go after particularly tiny animals, like mice.
New World Vultures Attracted to Smells
While New World vultures often have very keen senses of smell, their Old World counterparts aren't as lucky. New World vultures are frequently attracted to mercaptan, a gas that rotting corpses release and that they find very appealing. Turkey vultures (Cathartes aura) are a New World species that has even proven useful in notifying people of natural gas spills, simply by hovering persistently over them. Gas companies have used mercaptan in their product as a means of encouraging this help from vultures.
Herbivores over Carnivores
Scavenging is the vulture area of expertise, which is why the birds don't have a reputation as picky eaters, to say the least. That doesn't mean that they don't often have favorite foods, however. Vultures tend to be especially attracted to the carrion of herbivorous creatures. They don't enjoy the carcasses of meat eaters as much. Despite that, they don't hesitate to munch on carnivorous carrion if they have no other options.
Vultures and Fresh Foods
Vultures are usually especially enthusiastic about dining on animals that were just killed, if they can find them. They don't enjoy carrion that has been sitting out for hours and hours as much. In most cases they have no choice but to eat decomposing flesh, however, as it's the most pungent and tracking it down is therefore easiest. Vultures spend a lot of time in the sky diligently looking for any animals that might be especially frail. Eyesight is a strong suit of vultures. They often patiently await an animal's demise from above. Once they're sure that the prey is dead, they swiftly swoop down for mealtime.