It was a dark and stormy night, well not so dark, but stormy on this late October day. Nearing home, I spied twenty or so Turkey Vultures hunched over the branches of what I call the haunted tree; it looks like the iconic creepy tree you imagine seeing on a Halloween night. The tree was old, tall, leafless, with many twisted and gnarled branches, eternally spooky—and even more creepy with those vultures, looking ever so miserable in the twilight. It was an iconic vision worthy of a photograph.

Vultures, of any kind, do not gross me out; in fact, I am fascinated by them. Maybe not so much in our urban and suburban environments, but if we live in a more rural area, we realize the impact vultures make because they are truly nature’s clean-up crew. It is a dirty job, but someone must do it, and if they did not, we would see a lot more carcasses lying around. What we do tend to see here, in Pennsylvania, is our two native species, the Turkey Vulture and the Black Vulture, soaring effortlessly—riding the thermals high above us on any given day.

A Black Vulture (left) holds its wings flat and is generally smaller than a Turkey Vulture (right), which holds its wings in a V shape.

Turkey Vultures’ wingspans are around six feet, and five for Black Vultures. The U.S. has three species, and there are eleven altogether in the Americas, including the beautiful, yes beautiful King Vulture.

King Vulture

Vultures have amazing gifts that help them do their jobs efficiently, although vocalization is not one of them—they tend to hiss, whine, or grunt. Turkey Vultures, to me, are the most fascinating. We do not usually associate birds with a phenomenal sense of smell, yet that is exactly what Turkey Vultures have. They are like the bloodhounds of the sky. They can sense ethyl mercaptan, a gas produced in early decomposition, from hundreds to thousands of feet in the air. In fact, ethyl mercaptan is used in gas pipelines (and the gas ranges in our kitchens) as a safety measure. The smell of it indicates gas leaks, and Turkey Vultures sometimes gather on commercial gas lines where leaks are present. They can detect a carcass completely hidden from view within hours of death. The Turkey Vulture’s sense of smell, when compared to other super smellers like dogs or sharks, is best at long-range detection covering large areas. Dogs are extremely good at precision and discrimination detection, and sharks are great at directional tracking in the water. In addition to an amazing sense of smell, vultures’ stomach acids are so strong that they neutralize pathogens like anthrax and botulism.

Black Vultures, on the other hand, do not have that exquisite sense of smell. They tend to follow the Turkey Vultures and have been known to steal their finds, as they are more aggressive. Both birds, however, have a very important role to play. By cleaning up carcasses quickly, they reduce the spread of disease and keep our environment cleaner.

Unfortunately, vultures, like other raptors, are very sensitive to pesticides and poison bait, lead from ammunition in carcasses, and secondary poisoning from eating contaminated animals. These toxins tend to kill local vulture populations, yet surprisingly, in Pennsylvania vulture populations are stable and even increasing in some areas. The Black Vulture’s range has been spreading northward—they were originally mostly found in the southern counties of the state. Overall, their numbers look good, at this time, in Pennsylvania.

This was not the case in Southeast Asia in the 1990’s and early 2000’s, where a near mass extinction of vultures occurred, a 95-99% decrease in their populations. As their populations decreased, events cascaded. There was an increase in carcasses that led to sanitation issues, increases in the number of feral dogs that filled the vultures’ ecological niche, and a corresponding increase in the prevalence of rabies. The vultures’ decline was attributable to the drug diclofenac, which was used by veterinarians to treat cattle for pain and inflammation. When the cattle died, diclofenac was still present in their tissues, and the vultures who feasted on the cattle died of kidney failure. It nearly wiped out several vulture species. Recovery of these populations is still underway as several governments banned the use of diclofenac, and safer alternatives were introduced. Safe feeding zones for vultures were also introduced in some places.

In Africa, the problem has been poachers. When poachers leave parts of a slaughtered animal behind, vultures quickly flock to it, and observant rangers will also arrive, wanting to track down the poachers. But if the vultures are not present, then rangers will not be able to detect that telltale sign of poaching. So, in some cases when poachers kill a rhino or elephant for its horns or tusks, they intentionally kill vultures too with quick-acting poisons like cyanide to cover up their poaching crime. In addition, farmers poisoning carcasses to kill predators like lions or hyenas inadvertently, though frequently, kill vultures as well. Certain African vulture populations have decreased 80-97% percent.

Back in Pennsylvania, Hawk Mountain has been studying Turkey and Black Vultures since 2003, and they have tagged many birds. There is a citizen science project through Hawk Mountain where you can report sightings of tagged birds. Turkey Vultures carry light blue tags on their wings, and Black Vultures have yellow ones. Click here for the reporting form. Additional information on vultures can be found on the website of the Department of Conservation and Natural Resources here.

Many cultures hold vultures in reverence, and in many they are part of spiritual practices. Some Native American cultures believed that vultures were “purifiers,” and others saw them as messengers from the underworld. An article, Nature’s Silent Guardians: Celebrating Vultures on International Vulture Awareness Day, by the Society for the Protection of Nature in Lebanon stated, “Vultures symbolize renewal—an essential reminder that death feeds life in balanced ecosystems.” We can protect these stewards of our environment by dealing with problem rodents without using poisons. Poisons upset the ecological balance, and in nature, everything is about balance. Let us respect these birds for the incredibly important job that they do.

Barbara Beck, Richland Township Bird Town Leader

Photo credits:

Black Vulture (adapted), by Manuelito2021consupadre, licensed under CC BY-SA 4.0
Turkey Vulture (adapted), by Mike Baird, licensed under CC BY 2.0
King Vulture, by Wang Cai, licensed under CC BY-SA 4.0
Group of Turkey Vultures, by Thomas Brown, licensed under CC BY 2.0