Summer is approaching, and life is thriving outside. One animal that I associate with summer is the turkey vulture. There’s just something linking heat and seeing a turkey vulture circling above my head.
If you live in the United States, you’ve likely seen turkey vultures as well. Turkey vultures (Cathartes aura) are found throughout the Americas, from southern Canada to the southern tip of South America. Although they look similar, turkey vultures are not related to the vultures found in the Old World (Europe, Asia, and Africa). Instead, Old World vultures and New World vultures like the turkey vulture have undergone convergent evolution: because they occupy similar roles in their respective environments, they have evolved similar adaptations.
Some turkey vulture adaptations are absolutely wild, though. Let’s take a closer look.
- Large but light
- Turkey vultures are large birds: their bodies are on average 2.5 feet with a wingspan of 6 feet. But even with this large body, turkey vultures are surprisingly light. They weigh on average only between 2 and 4 pounds. Their light weight contributes in part to the turkey vulture’s flying patterns: turkey vultures are so light that they can literally just float in the sky on pillars of warm air known as thermals. In fact, turkey vultures are an example of static soaring flight. They flap their wings very infrequently and rely on the thermals to stay floating.
- Meat’s on the menu
- Turkey vultures are scavengers and eat animals they find already dead. In fact, turkey vultures literally can’t kill their own prey: their feet are weak and flat with blunt talons (imagine chicken feet instead of hawk feet). The only animals they are capable of killing are small, weak individuals, so pre-killed meat really is the best option for turkey vulture food. Still, turkey vultures are much pickier than books and movies give them credit for. They won’t eat extremely rotten carcasses, and they prefer meat that is as fresh as possible. Unfortunately, however, they sometimes have to wait a little bit: they can’t always pierce the hide of corpses and may have to wait for it to soften. But turkey vultures are great at foraging and will pick out the softest bits of a body first, so they don’t need to wait too long for a snack.
- Digestive powers
- “Won’t eating dead animals make them sick?” Good news: not at all! Turkey vultures have an incredibly acidic stomach, so they can eat just about anything without getting sick. In fact, turkey vultures can eat animals that died from things like anthrax, botulism, cholera, and salmonella without suffering from any side effects! This strong digestive power is why turkey vultures play such an important role in ecosystems: they are nature’s garbage disposal and help stop carcasses from accumulating and diseases from spreading.
- Sense of smell
- Turkey vultures are one of the few birds that find their meals by scent: they are able to locate rotting bodies by picking up the scent of ethyl mercaptan. This gas is produced very early in the process of decay, and there only needs to be a few parts per trillion of ethyl mercaptan in the air for turkey vultures to find carcasses. Turkey vultures are so good at smelling that they are able to smell carrion that is only 12 – 24 hours old. And this heightened sense of smell is reflected in their brains, too. Turkey vultures have a much larger olfactory region in their brain than other birds.
- Bald head
- The turkey vulture got their name because of their bald head, which from close-up kinda looks like a turkey head. Now, a turkey vulture’s bald head is more than just a fashion statement; it’s actually a very important adaptation. Having a bald head helps turkey vultures keep clean, as there are no feathers for bits of meat to get stuck on. Another head adaptation is the hole they have above their beak. This hold might look like a large nostril, but it’s actually a bony structure that protects the real nostrils just above this opening. Having this structure helps turkey vultures not get food in their nostrils while eating. And, if meat does get in the hole, turkey vultures can easily pick it out with a talon since there are no feathers for the meat to get stuck to!
- Warming up
- If you’ve seen a turkey vulture on the ground or in a tree, you’ve likely seen them in a horaltic stance, or with their wings spread. This stance is thought to have multiple functions. As you may expect, standing with your wings spread in the sun can help warm your body or dry your wings if it’s been raining. Some people think that the horaltic stance may also be used to help bake off bacteria from the wings.
- Keeping cool
- So that’s getting warm, but how do turkey vultures cool off? Easy – they just defecate on their legs! In a process called “urohidrosis,” turkey vultures defecate on the scaly parts of their legs and then let the water in their waste evaporate. This evaporation works to cool them off, similar to how sweat evaporating cools us off. Turkey vulture waste also doubles as leg sanitizer, since it contains high amounts of uric acid. This uric acid helps kill off bacteria that the turkey vulture may have picked up while walking on its dinner.
- Turkey vultures also have a use for waste coming out of their mouths: they vomit as a defense mechanism. Most animals understandably do not enjoy getting puked on, especially if the vomit is a semi-digested carcass. Between the smell and a stinging sensation if the vomit gets in the eyes, turkey vulture vomit is a good way to keep others away. Turkey vultures will also regurgitate their meal if startled soon after feeding – consuming large quantities of meat can make it difficult to lift off of the ground and sometimes you need to drop some weight to get away. Since this meat is just regurgitated and hasn’t been digested yet, most predators will take the free meal rather than continue chasing a turkey vulture.
One last fun fact. You know how the villain in Westerns will threaten to leave the hero’s body out for the buzzards to eat? We understand them as referring to vultures, but their threat would mean something different in Europe. You see, while “buzzard” is a colloquial term for vultures in North America, the same term refers to some species of hawks in Europe. So if you really want to be specific in your threats, make sure you use the right name for the bird you want to be describing!