Blane Klemek column: Turkey vultures exhibit unique traits
On my way recently to drop my son off at Neilson Spearhead Center for a week of working and learning on "Dan's Crew" for the first week of the preserve's Young Naturalist Program, we saw a dead deer along Hubbard County Highway 9.
A large bird was sitting on top of the carcass, another on the shoulder of the roadway a few feet away. Three other birds were perched in nearby trees. Even before we could positively identify the birds, we knew that turkey vultures had discovered their new meal of the day.
I'll be the first to admit, I don't know a lot about the natural history of turkey vultures, yet I find them extremely interesting. I also made the comment to my son that I knew nothing about their nesting behavior, that I've never encountered a turkey vulture nest, and that I wasn't even sure if they nested in northwestern Minnesota - I just assumed they do since they're prevalent throughout the Northland every summer.
I believe when one thinks of vultures, most people would not think of Minnesota as being the home of these birds. The fact of the matter is, there are plenty of vultures here, but only one species - the turkey vulture. They are fascinating and very specialized birds.
First off, turkey vultures are big and eagle-like in appearance, especially in flight. With a body length of nearly three feet and a wingspan of five and a half feet, it's easy to understand why people confuse turkey vultures for eagles or large hawks. However, a closer look will reveal a much different-looking bird - on the ground, roosting and in flight - from eagles and hawks.
Turkey vultures are masters of soaring and do so effortlessly as they ride the thermals and updrafts created from rising heat and air currents. They do so by rocking their bodies back and forth as they catch the air currents on their outstretched wings.
While eagles soar with wings stretched horizontally from their bodies, turkey vultures hold their wings in a "V" as they soar in ascending circles above the landscape. Their heads, when compared to that of eagles', are smaller and featherless, and their wings are two-toned in color with black wing-linings and silver-gray flight feathers.
Turkey vultures are also one of very few species of birds with highly developed senses of smell. Large nostril openings within their beaks are a clear sign of the vultures' amazing ability to detect its favorite and almost exclusive food item: carrion. By soaring above the earth, the birds are able to detect carcasses of animals by both scent and sight.
Turkey vultures, like many other vultures, have featherless heads that serve a very good purpose. As one would expect, a rotting carcass contains a host of bacteria and parasites, all working synergistically in breaking down the flesh of the carcass.
Thus, having a naked head is just the ticket when one has to make a living by probing the insides of rotting carcasses. Feathers would be exceedingly difficult to keep clean while, on the other hand, a featherless head is easier to keep clean. In the turkey vulture's case, bald is beautiful, efficient and necessary.
Also interesting to note, recent genetic work has shown that turkey vultures are more closely related to storks than they are to hawks and eagles. Nevertheless, the birds are classified as raptors. And the name "turkey" was given to the bird because of the similarities between its head and that of the wild turkey. Both species have naked and reddish heads.
Come to find out, and something I hadn't considered, turkey vultures don't build stick-nests in trees like I had assumed they did. Rather, turkey vultures nest directly on the ground. They scratch a small depression in the substrate and deposit their eggs, usually two, sometimes three, on the ground inside of caves and crevices, on cliffs, the burrows of mammals, underneath fallen trees, in logs and even inside of abandoned buildings.
Additionally, since turkey vultures are unable to carry meat and other food to their chicks, they must regurgitate partially digested flesh at the nest site for their offspring to consume. Other birds, such as storks, pelicans and cormorants, do this, too.
Turkey vultures also have a nasty habit of vomiting when frightened. Theories abound as to why. Some believe the action repels predators. Others believe it serves two purposes: to provide an alternative meal for a predator while the turkey vulture makes its escape and to lose weight quickly so they can make a hasty getaway from a predator.
Another interesting detail about turkey vulture natural history is that the birds routinely defecate on themselves, namely their legs and feet. Since the excrement of a turkey vulture is highly acidic, it is believed that the material effectively kills bacteria that might potentially find their way onto the bird's legs and feet because of walking on contaminated flesh. And since birds don't sweat, it's also reasoned that the excrement helps keep a turkey vulture cool on hot days.
Indeed, despite traits not so endearing, I think we're fortunate to have such a unique bird living and breeding here in northern Minnesota. Though perhaps not as majestic looking as the bald eagle, I would argue that to fly as gracefully as a turkey vulture would be anyone's delight, as we get out and enjoy the great outdoors.
Blane Klemek is the Bemidji area assistant wildlife manager, DNR Division of Fish & Wildlife.
He can be reached at firstname.lastname@example.org