BIG ARM — The first of up to 60 bighorn sheep on Wild Horse Island received their eviction notices Wednesday morning.
The notices came with a helicopter ride, medical checkup and new homes elsewhere in Montana.
The capture-and-relocation project is not quite an annual event yet, “but it’s turning into one,” said Montana Fish, Wildlife and Parks biologist Bruce Sterling. “We’ve done it four of the last five years.”
And many more times during the past 30. Sterling estimates 850 sheep have been removed from Wild Horse over the past three decades, and used to bolster other herds in the state.
They’re aiming to move 60 more — 40 rams and 20 ewes — over two to three days this week.
The ones now being captured and flown, suspended from helicopters, to the mainland, are destined to join two separate herds in the northwest corner of Montana.
The populations of those herds are falling. The one on Wild Horse, which has no real predators save for an occasional coyote, just keeps growing. An estimated 35 to 40 lambs are born on the island each year.
It’s allowed FWP to use the Wild Horse bighorns as a nursery herd, according to FWP Region 1 spokesman John Fraley.
The agency has augmented, and even started, other bighorn herds with Wild Horse sheep.
If the transplants didn’t occur, the animals would face an uncertain future on Wild Horse, Sterling said.
“Theoretically, we don’t know” what would happen if the bighorn herd was left untouched, Sterling said. “But more than likely there would be a population explosion, and then some sort of die-back, where the sheep would die off because of disease or starvation. Obviously, no one wants to see that and we’re trying to prevent it.”
Disease becomes a greater threat, Sterling explained, if a growing herd lessens the food supply and a bad winter puts the animals under additional stress.
Relocating bighorns also helps preserve the island’s short-grass prairie habitat that is vital to the sheep and other wildlife.
Ninety-nine percent of Wild Horse, a 2,164-acre island in Flathead Lake, is a primitive state park. The bighorns share the island with a herd of mule deer and six wild horses, and FWP believes the optimum number of sheep the island can carry is between 100 and 125.
The right number
There is invariably more than that. Sterling counted a minimum of 155 bighorn sheep in an aerial survey last week, and emphasized that’s not the total population, just the number he saw.
“We figure 60 is about the right number to remove,” he said.
It gets progressively harder as the operation goes on and the sheep, startled out of their often idyllic existence on the island, figure out what’s going on and become more elusive.
Cold weather is a key. The bighorns’ body temperatures shoot up when they’re under stress, and that can kill them.
Pilot Rick Swisher, the owner of Quicksilver Air, had 17 good-sized rams on the mainland before lunchtime Wednesday.
Swisher’s crew includes a “gunner” and two “muggers” who remain on Wild Horse throughout the day.
The gunner shoots a net over the animals from the helicopter and the muggers leap out to place hobbles on the sheep’s legs and a blindfold over their eyes.
The blindfolds calm the animals, which don’t react to what they can’t see. They’re then untangled from the nets, placed in bags and airlifted to a staging area at Big Arm State Park.
There, they’re laid on bales of hay and a host of FWP biologists and volunteers check them out. Nasal swabs and throat cultures are taken, blood drawn, fecal samples collected and body condition index tests administered.
Finally, they’re loaded in horse trailers. This year’s bighorns are bound for herds in the Kootenai Falls Wildlife Management Area near Libby, and Berray Mountain in the Bull River country northwest of Noxon.
Quicksilver is paid by the animal — the contract is usually for somewhere between $550 and $600 apiece — and the money comes not from taxpayers, but from the auctioning of a Montana bighorn ram hunting permit at the annual Wild Sheep Foundation Convention.