The bighorn sheep herd at Custer State Park welcomed some new members Wednesday, as 10-15 sheep were taken from Badlands National Park and added to the herd at CSP.
The move, according to visitor services program manager Kobee Stalder, is part of 10-year plan to get the herd back to the level that is was roughly 10 years ago, when a pneumonia outbreak threatened to deplete the herd entirely.
"They’re a native species to South Dakota, so we’re trying to regrow that population after the pneumonia outbreak," he said.
Ten years ago the herd had close to 200 sheep, but the outbreak cut those numbers down to 20-30, which is where it has been ever since.
The disease impacted the lambs the hardest, Stalder said that every year the herd would have, at the most, one lamb survive every year. Some years, no lambs would make it through without catching the disease and dying.
The sheep that were taken from the Badlands were all either lambs or ewes (females), but mostly ewes.
In the past two years the lamb population has been on the rise, due to some methods being taken by South Dakota Game, Fish and Parks.
"We had our wildlife biologists come in, and they found out that some of the sheep were chronic shedders of the disease, meaning they shed the disease every year," Stadler said.
Shedders are carriers of the disease.
Those sheep that were shedders were taken to South Dakota State University for further research, and it also helped the park's herd become more healthy.
Two years ago the lamb population in the park was eight. A mountain lion attack last year dropped that number down to four, but those numbers are still up from recent years.
Stadler said the ultimate goal of the 10-year plan is to bring the herd's population back to 150 sheep.
The method of catching the sheep at BNP is an interesting one according to Stadler. He said from a helicopter, park officials will shoot a net gun at one of the sheep and once it was caught in the net, it allowed another official to jump on the sheep and take it to a nearby trailer.
The sheep were released by the Peter Norbeck Outdoor Education Center and taken north to join the herd, where Stadler said he was optimistic there won't be any problems with disease or socialization of the new sheep.
"They’re all clean, our herd has been clean for two years. Basically you’re adding clean sheep with more clean sheep, should just go right into the herd pretty easily," he said. "I think if we were introducing rams (male sheep) there might be some socialization challenges but since they’re all female and lambs there shouldn’t be any challenges with that."