Ah, the harbingers of spring, red-winged black birds, crocus flowers, chorus frogs and turkey vultures! What? Turkey vultures? Connected more with death than renewed life, the arrival of turkey vultures from their winter haunts is actually one of the more predictable, and early, spring signs.
The robin gets all the press, but in this area of the world, robins can be seen all winter, unlike the turkey vulture that heads south in late fall and arrives back in March. Kansas has a list serve for bird watchers to post interesting sightings and, all week, it has been filled with jubilant reports of turkey vultures.
Many years ago, a friend called and wanted me to come identify some large baby birds in an old abandoned house on their property. Carefully climbing the old rickety stairs, I heard loud hisses as I peered into the room. By an open window were two large baby birds, covered in snow white down, weaving their black heads, clacking their beaks and hissing even louder. It was quite the show and made me pause before getting any closer.
A turkey vulture pair, which mate for life, had chosen the upper story for their nesting site. Fortunately for me, the two chicks did not vomit on me. To this day I’m not sure why they didn’t, because that is their major defensive move.
Although they have attained a somewhat dubious reputation, due to their dining preference of dead animals, vultures serve a vital purpose in nature. By removing carrion, they reduce disease. In Africa and India, where many vulture species are in steep decline, humans are finding out the importance of their role in maintaining a healthy environment.
Turkey vultures utilize the Earths’ thermal updrafts, rising high above the ground, soaring on broad wings with a span of 67 to 70-inches. They also soar at low altitudes, searching for carrion. Unlike the majority of bird species, turkey vultures search for food, using their excellent sense of smell. A trait sometimes utilized by humans to track gas leaks.
Natural gas has no odor, which makes finding a leak difficult. As a safety measure to detect the gas, ethyl mercaptan, is added to provide a distinctive odor. Ethyl mercaptan is also a gas given off as animals decay, which attracts turkey vultures. A large congregation of turkey vultures over a pipeline could indicate a leak. Their sense of smell is so strong, they can detect ethyl mercaptan from hundreds of feet in the air.
A recent scientific study determined their olfactory bulb, the area in the brain responsible for processing odors, is four times larger than its close cousin the black vulture. The turkey vulture also has twice as many mitral cells that help transmit information about smell to the brain, as black vultures, despite having a brain one-fifth smaller.
Some of the turkey vulture’s other traits may seem disgusting, but are amazing adaptations to their ecological niche or job. Their red head, devoid of feathers, allows them to stay cleaner when they dive into carrion. Turkey vulture’s habit of urinating on their legs helps with cooling and killing of bacteria. They prefer fresh carcasses, declining to eat a carcass more than four days old and they eat carrion without contracting anthrax, botulism, cholera or salmonella.
Now that they’re back, we can be sure they’ll be cleaning up and reducing disease once again.