Vultures play a role in nature, cleaning up animal carcasses, but one type — black vultures — can sometimes be more aggressive and present problems for livestock.
Agricultural and government groups are notifying producers about their options for dealing with issues with black vultures, which are federally protected under the Migratory Bird Treaty Act of 1918.
David Marks works as the USDA Animal and Plant Health Inspection Service assistant state director for Iowa and Missouri, and he has worked on the black vulture issue. He says it has become more of a concern for livestock producers due to increasing black vulture populations and producers being more aware of the birds.
University of Missouri Extension state wildlife and fish specialist Bob Pierce says populations have increased in southern Missouri and the Ohio River valley.
“They’re a native species,” he says. “I think the populations have been increasing over the last several years for a number of reasons.”
Marks says Missouri is at the northern edge of black vultures’ range, in particular southern Missouri.
Turkey vultures, with their distinctive red head, are more common in the U.S. and are less aggressive than black vultures. They can have a gray head when they are juvenile. They hold their wings in a V shape when flying and soar for longer distances without flapping.
Black vultures have a gray-black head and hold their wings in a more flat, horizontal position and flap more. They also have white-tipped wings.
They usually feed on dead animals, but in large numbers they can be more aggressive and bother small or medium-size live animals, such as baby calves.
“The black vulture can become more aggressive than your typical turkey vulture,” Marks says. “It’s usually only when the population is too high. In rare instances, they can kill cattle.”
He says that when black vultures concentrate in large numbers, such as when fish die off in a pond or when dead animals from a livestock building are poorly composted, they can harass young calves nearby, in particular pecking at eyes, and the calves can die from the trauma. In even more rare instances, they can go after sheep or grown cows that are sick or calving.
Pierce says usually black vultures feed on stillborn calves.
Marks says the black vultures can also rip up shingles on buildings or tear up rubber such as on windshield wipers or car door linings.
While the birds are a protected species and producers can’t kill them without a permit, they have several options for control. The first step is keeping cattle nearby for calving.
“Ideally, if you know when your cow is about to give birth, bring them up to the residence, get them closer to human activity, if you can,” Marks says.
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Burying afterbirth can prevent it from attracting vultures. Also, getting rid of dead animals on the farm, covering them up and composting them, can avoid drawing the birds.
Producers are allowed to scare the birds without a permit, including shooting to scare the birds away.
“If they’re really causing problems, then you go to the next step,” Marks says.
That entails getting a permit to kill up to five black vultures. People can get those permits through Missouri Farm Bureau, which secured government approval to issue the permits. Marks says producers won’t be able to eradicate the birds, but killing a few can send a message to the observant birds, who have good eyesight.
“You’re going to harass them; you can kill one or two of them,” he says. “They’re going to see that.”
Marks says a key thing is to use one of the dead birds as an effigy — a very effective method for keeping the birds away.
“Hang the carcass upside down as an effigy,” Marks says. “You hang one of them upside down and they’re gone. They really don’t like that. Most instances, that’s all you need to do.”
Pierce also says effigies work well.
“That’s a real good control measure,” he says. “They’ll see that and be deterred from an area.”
Marks says producers can also call the USDA to do a site assessment and get technical assistance for how to handle the birds, or to request a turkey vulture carcass to use as an effigy.
The Livestock Indemnity Program can pay for losses in certain situations.
This process involves conducting a necropsy of dead livestock to determine if the black vultures killed it or if the birds merely started feeding on an already dead animal. The USDA can conduct the necropsy, or producers can request their veterinarian do it.
He adds that the indemnity program assumes a normal 5% mortality rate per year, so it covers losses due to black vultures beyond 5% of the herd.
Marks says he often gets asked why the birds are federally protected, given that they can be aggressive with living animals. He says the migratory bird treaty was an effort by the U.S. to partner with Mexico and Canada to protect a variety of birds. The black vultures, while they can occasionally do “gruesome” things, play a role in nature, Marks says.
“They do serve a purpose,” he says. “They are the ones who clean up the carcasses; we need that.”
Many animals who die in nature do so due to a disease, and vultures can prevent diseases from spreading by clearing up the carcass. Vultures’ stomachs are very acidic, which allows them to break down carcasses and keep them from being susceptible to many diseases.
“They clean up diseases in the animal kingdom,” Marks says.
People who have concerns about black vultures can contact their local Extension office, the USDA or the Missouri Department of Agriculture for additional resources and information.