The scenes described from Indiana’s farmlands and elsewhere seem to jump from one page in a horror novel, with black vultures descending into the forests and pastures of the Midwest and beyond.
Farmers report gruesome attacks on their animals: wakes with large, hunched black birds that feast on newborn calves that hatch from their mothers and sometimes hunt the mothers themselves.
“They’ve gotten really aggressive over the past few years,” said John Hardin, a ranchers in Scott County, southern Indiana, about 20 miles north of Louisville, Kentucky, who often sees eight to ten of the birds on his farm. At least two of his calves were killed by vultures, maybe more. “They like the navel area and they’ll take it to the bone and hide.”
Vultures are often referred to as “nature’s garbage disposers” because their highly adapted digestive and immune systems enable them to eat dead and sick animal carcasses with impunity. While scavenging is considered a critical ecosystem service, reports of black vultures hunting live animals are relatively unknown, some experts say, and some have voiced skepticism that predators are actually taking place.
The situation in Indiana this summer proved alarming enough that farmers can now quickly obtain permits – which the Indiana Farm Bureau received from the US Fish and Wildlife Service – to “take” or kill up to three birds, one new Kraft program launched in other Midwestern states.
“These migratory birds come across the Ohio River,” said Greg Slipher, a livestock specialist with the Indiana Farm Bureau. “I got a heads-up from my colleague in Kentucky and he said, ‘They’re coming up to you,’ and he was right. In the past three or four years we’ve gone from a few reported incidents to many. “
Much remains unknown about the bird and why its numbers are growing in states where they were not seen a decade ago. They have traditionally been found in the southern United States as well as Central and South America, and it is unclear why they have significantly expanded their range to the north and west. Some speculate that milder winters could be a factor due to climate change.
From 2007 to 2019, black vulture breeding populations in the United States, excluding small parts of the Gulf Coast and south-central Florida, increased by one to four percent annually on eBird data analysis by the Cornell Lab of Ornithology.
The extent of the predation by black vultures is far from clear, as they are breaking new ground. One of the country’s leading ornithologists is very skeptical and concerned about the permits issued. Black Vultures are one of approximately 1,100 species protected under the centuries-old International Migratory Bird Treaty Act; Violating them without permission can result in heavy fines or even imprisonment.
“I’m going to take an extreme position here and say they don’t kill healthy calves,” said John W. Fitzpatrick, the recently retired director of the Cornell Lab of Ornithology in Ithaca, New York.
For seven years he ran the Archbold Biological Station in central Florida, which also includes a cattle ranch where black vultures lived. “They are often seen in trouble around stillborn or dying calves and quickly jump in on them,” he said. But, he added, “the idea that they are predatory of cattle is wrong.”
“In my opinion, it should be considered lore because it is not well documented,” he said. The vultures can occasionally attack a healthy calf, he said. But, “Are we really talking about something that is so widespread and economically destructive that we have to start by allowing a protected bird to be destroyed?”
The vultures are large birds, nearly five pounds in weight, topped with a helmet of gray, featherless skin. They have a large wingspan of up to five feet, which creates loft when flying on thermals and spotting prey. They are one of three species of vulture in the United States; the turkey vulture and the critically endangered California condor are the other two.
“The black vulture is an amazing bird,” said Dr. Fitzpatrick. “They are loyally paired, have amazing and complex social behaviors, and are super smart. They guard the nest closely. The eggs hatch and become those fluffy white chicks, and for a month or six weeks you can always find out if a nest is around because one of them sits in the same place day after day, week after week. “
Dr. Grant Burcham is a veterinary diagnostician at Purdue University’s Heeke Animal Disease Diagnostic Laboratory, which operates a research cattle ranch.
Dr. Burcham said he received a calf killed by vultures and euthanized two others who were attacked. The autopsies showed that the calves were not healthy – two had scours, a bowel disease, and the third a broken leg – and may have been picked by vultures who sensed their vulnerability. “The animals were dehydrated and would have been visibly slow, which is probably why they were deliberately attacked.”
A recent paper concluded that while predation by carrion birds in Argentina, including the black vulture, is perceived as common, it is not common at all.
Patrick Zollner, professor of ecology at Purdue University, agreed that there was a lack of empirical evidence for the predation. “What is completely unknown in Indiana and most places is how often this happens,” he wrote in an email. “Closing this gap is one of the goals of our ongoing research.”
Marian Wahl, PhD student with Dr. Zollner at Purdue, who studies the birds in Indiana, said she believes the black vulture numbers in the United States are several million and in Indiana from just a few decades to about 17,000 now.
While the US Fish and Wildlife Service may issue special permits for killing birds that cause damage, the process to obtain them can be lengthy and cumbersome, costing $ 100 each. The relatively new program in Indiana and elsewhere allows state farm offices to obtain large numbers of permits and issue sub-permits, which experts say is more responsive.
Mr Slipher said he has received 45 requests for “take” approvals and approved 22 since the program went into effect in early August.
While the permits allow anyone to shoot three birds, Mr. Slipher says there is a better strategy.
“I advise you not to go out and shoot all three on the first day,” he said. “One of the things we know about these particular species is that they are very responsive to their own images. We encourage our producers to shoot this first bird and hang this bird up as a portrait. “
It’s an approach that has helped the hardest-hit producers in Kentucky – something. Although real and false hanging effigies are widely used to disperse the birds and there are studies showing that they work, the effectiveness is not well understood.
“If you use an image to disperse a quarter, does that keep you away from the cattle or do you just pull down the street to a quarter and keep coming back to the same farm?” Asked Mrs. Wahl.
Joe Cain of the Kentucky Farm Bureau said the black vultures appeared in his state in the early 2000s and that in 2015 Kentucky began the new licensing system that was just being rolled out in Indiana.
“We only hit the hot spots,” said Mr. Cain. “The biggest problems are those who call us. There are many more out there who are seeing the devastation, but at least they know there is a program out there to help them protect their livestock. “
The permits did not significantly reduce the number of cattle killed, officials said. About 500 to 600 cows were killed annually in Kentucky, adding that more lambs, kids, free range chickens and turkeys would be felled as vulture populations increased.
Other tactics include making loud noises with devices such as propane cannons, firing pyrotechnics, spraying birds with high-pressure hoses, and using guard dogs. Since the vultures often perch in large dead trees to survey the landscape and look for prey, felling these trees can also provide relief. The effectiveness of these measures is part of the study that Ms. Wahl and Dr. Zollner performed.
Mr Cain wants federal law to be changed to help farmers. “We asked Congress for a Safe Harbor provision,” he said. “When they discover looting, it’s unreasonable to say, ‘I’ll go home, get a permit application, and wait two days to get the permit.’ When you see that, it makes a lot more sense to protect your livestock. “
A vulture’s attack on live prey is a dire scenario, say farmers. “The birds turn in during birth – essentially at the most vulnerable moment,” said Mr. Slipher. “Literally, while the calf is on its way out of its mother, we get black vultures that attack the calf and attack the mother.”
The bird often picks out the eyes, nose, mouth, and navel. Farmers say that every animal that dies is valued at $ 1,000.
They are annoying for other reasons too: They tear off asphalt shingles from houses, tear off windshield wipers and rubber seals around the sunroofs of vehicles, and tear open seat covers on agricultural machinery and boats.
Your stomach acid is almost as corrosive as battery acid, and your feces, urine, and vomit can eat up on rooftops, towers, and other places.
But vultures are also a proven and critical part of the ecosystem. In India, for example, there has been massive vulture death due to the widespread use of a veterinary drug that is toxic to birds. This led to an increase in rabies. Vultures used to clean up dead cattle and other litter; When they disappeared, the dogs began to feed on the waste, and as their numbers increased, so did the rabies numbers.