Jason Tower made his rounds through the grounds of the Southern Indiana Purdue Agricultural Center last fall when he came upon a gruesome site: One of his calves lay dead on the ground surrounded by feasting vultures.
Tower, who directs the agriculture center, saw the calf up and walking the day before, perfectly healthy. He’s confident he knows what happened: a black vulture attack.
Black vultures are smaller and more aggressive than the well-known turkey vultures and are characterized by black feathers with silvery-white primary feathers that show during flight, and a brown, gray or black featherless head, according to the Purdue Extension of Dubois County. Also unlike the turkey vulture, which only feeds on carrion, black vultures like to add fresher meat to their diets, flocking together and working as a team to take down small prey such as wild animals and calves, sheep and goats.
They’ve become annual visitors to the Southern Indiana Purdue Agricultural Center when the cows on the farm in the northeast part of the county give birth in the fall, and Tower estimates the birds are responsible for the loss of about two calves a year. That doesn’t sound like much, but a fully grown cow is worth $1,000 or more, and the vultures have been plaguing Tower’s farm for about eight years. At two calves a year, that’s a loss of about $16,000.
The Southern Indiana Purdue Agriculture Center isn’t the only local farm contending with black vultures. Farmers in Dubois and surrounding counties whose herds give birth in the spring have already reported black vulture losses this year.
Linda Schroering witnessed firsthand the damage black vultures cause two years ago when the birds attacked livestock on her family’s farm in Hall and Marion townships. She still has the photos.
“For the small farmer who doesn’t have big herds and can’t afford anymore losses, these birds wreak havoc,” Schroering said.
Unfortunately, conservation laws limit how farmers can respond to the birds’ threat. The Migratory Bird Treaty Act protects the vultures, making it illegal for farmers to kill the birds without a permit from the Migratory Bird Permit Office, which is based in Bloomington, Minnesota. The permit process is time-consuming and complicated.
“It’s just challenging for someone who knows there’s a problem to take care of their animals as quickly as they need to,” said Ken Eck, Dubois County’s Purdue Extension agriculture and natural resources educator.
Still, there are some options for farmers without a permit. Farmers in other afflicted areas report that habitat modification to remove easy roosts for vultures, hazing with red lasers and hanging the effigy, or fake, carcass of a dead vulture in the area help deter the birds.
“It’s kind of like putting a scarecrow up,” Eck said of the effigy.
Livestock guardian dogs, traditionally used for preventing predation of sheep and goats, have also been reported to deter the birds Although small dogs and cats could be prey, Eck said there haven’t been reports of the birds attacking pets.
The issue likely won’t go away anytime soon. Black vulture populations have been on the rise since the passage of the Migratory Bird Treaty Act in 1918, leading the birds to spread from the southeast states into Kentucky and Indiana.
“They’re becoming more common than turkey vultures,” Eck said.