Wednesday, September 27, 2023

Black VuLtUrEs

Fossil records indicate that black vultures were part of the fauna in Europe approximately thirty-four million years ago. Today these vultures are only found throughout North and South America. Traditionally black vultures were found in the southeastern United States, but sometime in the 1990’s they began spreading their population further north and westward into the midwestern states.  These large, gregarious birds occur in Missouri, predominantly in the southern portion of our state. However, in recent years they have been expanding their range to include Northern Missouri as more sightings are being reported in our corner of the state.

Black vultures are cousins to the more common turkey vulture, and approximately the same size with a 4.9-foot wingspan. Black vultures tend to be more stocky in their build and are uniformly black in color including their featherless head. In fact, their species name of “atratus” translates to “clothed in black.” The common name vulture is derived from the Latin word Vulturus which means “tearer” and refers to their feeding habits. Like all vultures they feed predominantly on the carrion of a wide variety of animals. Of the two species of vultures living in Missouri however, the diet of the black vulture is much more varied and does include living animals as well as vegetation. They may feed on birds, reptile eggs, small mammals, as well as refuse from dumps, and controversially the offspring of livestock. Reports from cattle ranchers began pouring in of black vultures attacking newly born calves by pecking their eyes and or nostrils and mouths. This causes the calf to go into shock making it possible for the black vulture to ultimately kill and eat the calf. They extend this behavior to piglets and lambs as well. Why black vultures exhibit this type of behavior has yet to be fully determined, but there are ongoing studies to try and gain some insight and hopefully some answers. With adequate information, it may be possible to come up with solutions to protect livestock as well as the vulture. The black vulture is the only New World vulture known to feed on livestock, the more mild-mannered turkey vulture does not, however he does sometimes get blamed for it. If you are a cattle rancher or livestock owner and see vultures feeding on your calves you probably aren’t going to care who killed the calf, only that its dead and being fed on. It is vitally important though to make that determination so innocent animals aren’t being slaughtered in the name of protecting your livestock. Young turkey vultures often do not have the classic red head and can easily be mistaken for a black vulture. Turkey vultures will show up to a recently killed carcass to feed and may get caught in the crossfire of the bad behavior of the black vulture. It can be very distressing to lose livestock, especially in such a horrific way. This is not only upsetting but impacts ranchers financially. It is imperative that an accurate determination is made as to whether or not the black vulture is to blame for the death of a calf, or if the vultures are actually feeding on a stillborn and being falsely accused of killing the calf. Black vultures are protected under the Migratory Bird Treaty Act of 1918 in the United States. It is illegal to take, possess, or kill one without a permit. Getting caught killing one without due cause and special permits can cost you up to $15,000 and six months in prison. Always document and report issues these vultures may be causing and apply for the right permits to control the situation. This protects you, your livestock and potentially the vulture from wanton killing.

Until the 1900’s black vultures were appreciated as slaughterhouse cleaners, especially in the southwest where their populations were much larger. Misinformed humans began believing these birds were spreading diseases to humans and thousands were killed throughout the 1970’s. With climate change and an abundance of carrion and other food sources their population has rebounded and they have expanded their range. Vultures are an important part of a healthy ecosystem and are vital for cleaning up carrion. The feeding habits of these birds allow carcasses to decompose faster thus removing them from the environment much quicker. With a decrease in vulture populations there will be an increase in the populations of larger predators such as coyotes which may cause a more serious threat to livestock if left unchecked. The absence of vultures may also increase the abundance of rats and feral hogs which in turn will increase the potential for anthrax and rabies virus to increase and create definite health risks for humans. Vultures are not known to catch or transmit any diseases and have special enzymes in their digestive system which allows for them to eat decaying animal carcasses without risk of contracting pathogens that might make other animals serious ill or even kill them.

Black vultures are highly social birds with dedicated family bonds. They will share food with other family members and continue feeding their offspring long after they have fledged. They lack a voice box and communicate through hisses and grunts. When threatened they may regurgitate a recent meal as a deterrent and also as a means to release weight and be able to retreat more quickly. I’ve had the unfortunate opportunity to experience this first hand. Once while returning a baby turkey vulture to its mother inside a shed where she was rearing them, the baby let me know just how it felt about being handled by a human as it vomited all down the front of me. The smell simply cannot be described! Their corrosive vomit reeks of the death it has consumed. Believe me when I say it is a deterrent!

Turkey vultures on a recently deceased deer
Black vultures have a poor sense of smell, but keen eyesight. They often soar high in the sky above the turkey vultures waiting for them to smell a potential food source. Turkey vultures have a keen sense of smell and can home in on the gases emitted by a recently deceased carcass from up to a mile away. The black vulture will follow the turkey vulture to the food it so kindly sniffed out and then proceed to run them off with their much more aggressive attitude.

Of all the birds that grace our skies, vultures are my favorite. They are one of the most misunderstood and vilified of our raptors. Often held in contempt for doing what nature programmed them to do, and for generations were needlessly persecuted by misinformed individuals. These birds are unique and ecologically important for a healthy environment. Images of their large wings spread towards the sun as they bask, soaking up the heat of the sun’s rays is as recognizable as their silhouette soaring high in the sky. A sky without vultures would be an empty sky for sure. 


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