The number of vultures roosting on and near Bull Shoals Dam has dropped from about 300 to 40 since June 22, when three vultures were shot and their corpses hung on structures there, a spokesman for the U.S. Army Corps of Engineers said Thursday.
Vultures are scavengers, but they have an aversion to the dead of their own species. Corps spokesman Laurie Driver has added that killing some of the vultures was a "last resort."
While some vultures have always been around Bull Shoals Lake, they became a problem in October 2012, when about 1,500 vultures descended on the dam.
The majority leave before summer, and hundreds of vultures have been returning in the fall. But a core group of about 300 vultures has remained year-round.
Workers had tried pyrotechnics, propane cannons and hanging plastic effigies of dead vultures. The efforts rid the area of some of the vultures. But others apparently became desensitized to those measures.
"They used to fly off about 50 feet if we used some of our pyrotechnic stuff and then return," Driver said. "Now they are leaving for the day. And they are definitely staying away from the dead vultures. So right now we are seeing progress, and we hope that continues."
Driver said the dead birds were placed where the public can't see them. They were shot by an officer from the Arkansas Game and Fish Commission using a 12-gauge shotgun.
Driver said pyrotechnics and other methods will continue to be used to keep the vultures away.
"The dead-vulture effigies seem to be working well," said Bruce Caldwell, supervisory natural resource biologist for the Corps in Mountain Home.
"The live birds have kept a distance from them. The biggest plus is that they are much more scared of the pyrotechnics right now, and it clears them away for longer periods of time before the few birds that are left return."
The Corps got a permit from the U.S. Fish and Wildlife Service to kill as many as 125 black vultures and 10 turkey vultures. But they're hoping three will be enough. Both types of vultures are protected under the Migratory Bird Treaty Act.
Driver said there are no plans at this time to kill more vultures at Bull Shoals.
The birds roost on the dam. Their caustic droppings damage metal and painted surfaces, and discolor the concrete.
The vultures rip away at anything resembling rubber, including windshield wipers, car door insulation and even the rubber expansion joints separating sections of concrete sidewalk.
Driver said vultures also damaged the roofs of the powerhouses at Bull Shoals and Norfork Lake, about 25 miles to the southeast. Partially because of vulture damage, the roofs had to be replaced years earlier than expected, she said.
Bull Shoals Dam is on the White River about 12 miles west of Mountain Home. The dam is on the border between Baxter and Marion counties.
The dam is 256 feet tall and 2,256 feet long, and was once the fifth-largest dam in the country. Work began on the dam in 1947, and it was dedicated by President Harry Truman in 1952.
Metro on 07/03/2015