Seven bighorn sheep rams will be killed and removed from Flathead Lake's Wild Horse Island as part of a statewide bighorn sheep health and disease project.

The project, planned for the last week of February, will focus on rams of various ages. The project is being pursued as part of broader statewide research aimed at assessing the health of Montana's bighorn populations.

"I think this is the first time we've ever sampled them by killing them," said John Fraley, Montana Fish, Wildlife and Parks regional public affairs officer. "It's the only way to do this kind of testing … These tests can't be done on live sheep. They have to have sheep sacrificed so they can work on the carcass."

Fraley said agency biologists believe the island's sheep population is "ram heavy," so the removal of seven is not expected to have any effect on sheep reproduction.

A Dec. 2 helicopter survey counted 103 sheep, including 31 rams. That survey, however, is not considered a complete population census because not all sheep were visible during the flight.

A complete assessment of the herd's health is important, Fraley said, because the island population has been used numerous times to augment other populations in the state, including herds near Perma, Paradise, Hog Heaven, the Elkhorn mountains and the Rocky Mountain Front.

"If we're going to use Wild Horse as a nursery for other herds, we have to make sure that these sheep are in good shape and suitable for that," Fraley said.

Wild Horse Island, one of the largest islands in the continental United States, is a 2,163-acre state park on Flathead Lake. The island will be closed to the public the day the project is conducted. The project is currently planned Feb. 28, but the date could be adjusted based on weather.

The animals will be shot rather than drugged so the meat can be forwarded to food banks. The remaining carcasses will be transported to a laboratory for detailed analysis by a veterinary team.

The project team is led by Dr. Mark Atkinson, a veterinarian with Fish, Wildlife and Parks; Dr. Dave Miller of Colorado State University; Keith Aune, the state's research and technical services chief; and Neal Anderson, the Fish, Wildlife and Parks Wildlife Laboratory supervisor.

The team will test each carcass for multiple diseases and also perform blood serology and adrenal-gland stress research.

Reporter Jim Mann may be reached at 758-4407 or by e-mail at [email protected]