By Jeannie Marcure
Observing a group of Turkey Vultures cleaning up a deer carcass last fall tweaked my interest in these carrion eaters. I have to admit that before my research, I found these big black birds to be a little repulsive. After all, they eat dead and decaying things and I’d also heard a rumor that they sometimes vomit on people. Not a pretty picture—especially when you consider their diet! My reading led me to the website maintained by The Turkey Vulture Society of America and revealed some truly amazing and unexpected facts.
Although United States is home to three kinds of vultures, the California Condor, the Black Vulture, and the Turkey Vulture, only the Turkey Vulture is found here in Western Montana. These seasonal residents usually head south with the Autumnal Equinox and return with the Vernal Equinox and like the Capistrano Swallows, often return to their roost on that exact day. Turkey Vultures can often be spotted on fence posts or in trees near road-killed game. At 25-32 inches and with a naked red head, they are easy to identify. They can also commonly be seen soaring overhead, scanning for another meal. In flight they can be recognized by the dihedral (V) shape of their wings and by the fact that they seldom flap their wings—rather relying on thermals and updrafts to keep them aloft. Most other large soaring birds hold their wings straight and flap frequently. TV’s feel the air with the wing-tip fingers allowing them a soaring skill much admired and envied by experienced glider pilots.
The Turkey Vulture is family oriented and a group of vultures living together and sleeping at night in a tall tree is called a roost. Some roosts are known to be 100 years or more old. This means that the same family has used the same tree or trees as home for many generations. However, during nesting, a mating, monogamous pair goes off by themselves to lay two eggs and raise their young. They do not build nests as such but rather lay the eggs on the bare ground. Nests are often found on ledges on the face of a cliff, in a cave, a hollow tree or even in an abandoned building.
According to the Turkey Vulture Society, Turkey Vultures seem to live and work in cooperation and friendship and when there is a big feast available they somehow contact neighboring roosts to share the plenty. One observation near three dead cows reported three roosts feasting and living together until the carcasses were clean. They also seem to like human contact and often choose roost sites near humans. Turkey Vultures that have been injured and taken to rehab often become very attached to their handlers and follow them around much like a pet dog would.
Although the Turkey Vulture has acquired a reputation for vomiting, the truth is that it seldom regurgitates. However if it is cornered and feels threatened, a TV may roll over and play dead or it may project an offensive smelling vomit in a defensive manner. Mostly silent except when threatened, TV’s hiss to warn off enemies. Despite these somewhat questionable behaviors and the fact that they regard dead animals as fine dining, the Turkey Vulture is a very clean bird. Studies have shown that each bird spends up to 3 hours per day preening itself. Also they will bathe in water whenever they can. Large flocks have been observed going into a pond for a bath. They submerse, scrub, preen and shake and then walk up on shore to spread their wings in the sun for drying.
Turkey Vultures can locate carcasses by smell, a trait that is unusual in the bird world. They also have keen eyesight and search visually as well. Although we tend to spot them most often eating carrion, up to 50 % of their diet consists of vegetation. Lacking claw strength, the TV cannot and does not kill and its beak has neither the shape nor the strength to tear into a fresh carcass. Cathartes aura, the TV’s scientific name means “pacifier” or “cleanser” and the Cherokee Nation calls this bird “peace eagle” because unlike the eagle, which it resembles from a distance, it does not kill. The TV’s digestive system has the unique ability to kill any virus and bacteria in the food it eats. Tests performed by the USDA during a hog cholera epidemic in the south proved that the droppings and dry pellets that are regurgitated are clean and disease free. The pellets, which are smaller than a chicken egg, consist of dried hair, bone material and vegetation and are odorless. Animal food items in the pellets that were examined included, shrews, moles, squirrels, gophers, mice, rats, rabbits, birds, reptiles, insects, muskrats, opossum, raccoon, skunk, badgers and coyotes. Imagine the potential for the spread of disease (and the bad smell!) if these carcasses had rotted on the ground rather than being consumed and sterilized by the TV’s. Because of this unique sterilization ability, researchers are currently testing to see if digestion by a TV can disinfect rodent carcasses carrying Hantavirus. This research could be of great significance to human medical research in this area and may also lead to vital information for use in the event of biological warfare or a worldwide epidemic.
I’m very grateful to have these resourceful birds helping keep our earth clean and disease free, aren’t you?