LOUISVILLE, Ky. – They'll devour slimy newborn calves, full-grown ewes and lambs alive by pecking them to death.

First the eyes, then the tongue, then every last shred of flesh.

And there isn't much defense against black vultures and turkey vultures, both of which are federally protected and cannot be killed without a permit.

The Migratory Bird Treaty Act of 1918 covers all migratory birds, their nests and their eggs, which means that the birds can't be harmed without federal permission. Their nests can only be disrupted, as a deterrent, if there are no eggs or young in them.

But as the vultures, which are native to Kentucky, have multiplied in numbers nationally over the last two decades, they have become more of a problem for farmers. Each year, Kentucky farmers lose around $300,000 to $500,000 worth of livestock to these native vultures, according to Joe Cain, commodity division director for the Kentucky Farm Bureau.

It's not just farm animals. Small pets may be at risk too.

The birds can be valuable contributors to the ecosystem, disposing cleanly of animal carcasses. But their increased numbers have made them more desperate for food in other forms – even alive.

"With a vulture, it's like someone came in with a skinning knife," said Derek Lawson, the head herdsman for the 1,300-acre bio dynamic Foxhollow Farm in Oldham County. "It's all clean cuts. Usually, the hide's completely cut off, whereas with a coyote or dogs, it'll be torn and jagged."

Non-farmers may see the birds more often on the side of the road, pecking at rotting roadkill. They're easy to identify.

Black vultures have gray heads and hold their 5-foot wings in a horizontal position when in flight, according to the University of Kentucky Department of Forestry. Turkey vultures, on the other hand, are true to their name with bright red heads and a v-shaped in-flight profile.

Black vultures have historically been the most aggressive of the two and are more likely to feed on live animals.

These vultures normally migrate from northern South America, through Texas and along the southeastern U.S. to Pennsylvania.

Warmer winters may have increased the number of vultures in the U.S., said Wayne Long, the Jefferson County extension agent for the University of Kentucky College of Agriculture, Food and Environment. Vultures, he said, take advantage of climate change and hang around more in a spot they like.

Lawson said he's noticed more vultures since 2009, when he thinks they started nesting near Foxhollow Farm. He plans his year around the predatory habits of the vultures, which circle the skies in wait of anything dead or vulnerable.

He remembers one eerie morning that he saw a flock of 60 vultures perched on adjacent gates in one of his fields. He mainly worries about them during calving season, when they like to feast on easy marks.

His 2019 calving season opened with him topping a hill and seeing six vultures pecking a calf to death.

They like to play with the newborns, he said. They'll hop around and get the calf comfortable with them before they peck out their eyes.

"Then they can't see," he said, "so they can take them over."

The whole process, from the playful taunt to the complete skinning, doesn't take long at all, he added. Depending on the size, it may only take minutes. "They're very efficient at what they do."

Lawson said Foxhollow hasn't lost any full grown cows to the vultures, but the birds have taken down full-grown ewes while in labor, when both the mother and its baby are vulnerable.

He remembers finding a ewe once that had been in the process of giving birth when she was attacked. A full-grown ewe weighs between 160 and 180 pounds.

When the vulture got her, he recalled, the skeleton was completely together.

"And the hide was in one big cape coming off the back of the ears," he said. "You could pick the ear up and pick the whole ewe up. But there was no meat left on the bones."

Long, UK's Jefferson County extension agent, said small pets like cats and dogs may be at risk of attack just by nature of being small animals.

You must have a permit to kill vultures

Special federal permits, which cost $100 each, are required before a person can kill a vulture, and the permits must be renewed each year.

In 2015, the Kentucky Farm Bureau began buying the permits through a partnership with the U.S. Fish and Wildlife Service and offering sub-permits for free in limited numbers to eligible applicants.

Luckily for Lawson, the Foxhollow farmers have maintained permits since 2013 that allow them to kill a small number of both black and turkey vultures each year. Now the farm gets its permits through the farm bureau.

Without the permits, they could face a fine up to $15,000 or six months behind bars.

Foxhollow Farm first got a permit after it lost a number of ewes, lambs and calves in 2013, the oldest of which was a 2-week-old calf, to vultures.

The farmers had already tried to run the vultures off, to no avail. "Thirty minutes later, they're back out there," Lawson said. They decided the best course of action was to get federal permission to defend their herds.

The terms of the permit require that the permit holder use a waterfowl load: a steel shot shotgun between a No. 2 to No. 4 buckshot – the smaller the number, the bigger the projectiles. There are no specific caliber restrictions, but Lawson always uses a 12-gauge shotgun.

The farm animals aren't in danger of getting hit by the shells, he said. He's usually shooting at the vultures once they're in the air or trees. Besides, "if they're on a calf, the calf is already dead."

The vultures are smart, he added. By the time he sees them attacking an animal, goes to his shop to retrieve the firearm, they're already flying away. That's why during calving season, he keeps his shotgun handy.

"You got to catch them by surprise that first time," he said.

He usually has to kill a few in the beginning of the calving season, which he schedules for April 1 to June 1, and uses those early kills to deter the others.

He hangs the dead vultures upside down by bright orange haywire on cherry trees for the other birds to see.

It works, he said. The wings spread upside down is eerie, an effective deterrent to the others. The vultures will come in to investigate their dead comrade, but they won't eat it.

For several months, while bugs and weather give the dead, hanging vultures a taste of their own medicine, the live flocks are more wary. They circle high in the sky and wait before swooping in to attack a young ewe or calf or to dig in a compost pile for the last scraps of decaying flesh.

Vultures good for ecosystem

Lawson said his feelings about vultures are a constant balancing act. It's hard to watch his livestock attacked, but he knows the vultures are good for cleanup.

"You gotta have those lines," he said. "They are a necessary part of the ecosystem. Otherwise we'd just have dead stuff just laying around, slowly rotting over time. They kinda speed things up."

But, even with better permit accessibility through Kentucky Farm Bureau, Lawson said it's frustrating to go through paperwork to defend his herds. "It's kind of a hassle," he said.

Five to 10% mortality rate among the newborn calves is considered "lucky," he said, and he has to account for at least that much loss each season.

He'd like to find the birds' nests to disrupt them and send the vultures on their way.

But the vultures stop their hunting about 30 minutes before dusk, making it hard to track them back to their roosts. Lawson will keep trying, though.

For now, he'll keep an eye on the tree lines and on his herds, binoculars always by his side, in case the flying fiends get hungry and come in for a kill.