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FWP biologists, volunteers cull sick bighorns in East Fork of Bitterroot

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HAMILTON - On horseback, foot and in pickup truck, biologists and volunteers fanned out in the hills of the East Fork of the Bitterroot on Wednesday in an effort to slow the spread of a disease that's killing bighorn sheep.

Over the course of the day, they collected eight bighorns that had either died or were exhibiting the symptoms of pneumonia.

"We're trying to get to as many sick sheep as we can find," said Craig Jourdonnais, Montana Fish, Wildlife and Parks' Bitterroot-based biologist. "So far we are still batting 100 percent. All of the animals that we've collected were in some stage of pneumonia."

The dead sheep were brought back to a mobile state wildlife laboratory where researchers took tissue, blood and fecal samples that could eventually help unlock some of the secrets on what causes periodic die-offs in bighorn sheep herds.

The effort in the East Fork to aggressively cull sick and dying bighorn sheep from the herd to try to slow the spread of the disease is a first for the state.

"A lot of different things have been tried in the past, but none have really worked," Jourdonnais said. "We're hoping that by targeting those sheep that are for sure infected, we might be able to save some ... the approach is somewhat exploratory, but we know for sure what is going to happen if we do nothing."

In the past, some bighorn herds infected with pneumonia in Montana have seen dramatic die-offs in the 60 percent to 80 percent range.

So far, Jourdonnais and others have collected almost 40 bighorns from a herd that is estimated to be somewhere close to 200.

On Wednesday, FWP employees joined with volunteers from the Ravalli County Fish and Wildlife Association and the Foundation of North American Wild Sheep to look for sick bighorns.

Other volunteers have agreed to check on bighorn herds in the West Fork and up Skalkaho.

Researchers still have a lot to learn about what causes the periodic die-offs in bighorn sheep. There's concern that diseases can be transmitted between domestic and bighorn sheep.

There have been studies that show diseases can be spread from domestic sheep and bighorns confined in the same pen, said FWP Wildlife Veterinarian Jennifer Ramsey.

A die-off almost 30 years ago in the East Fork was thought to have started when domestic and bighorn sheep mixed together on state land.

The bighorns that have been collected in the East Fork so far have appeared to be in relatively good health, with the exception of their respiratory system, Ramsey said.

A healthy animal's lungs should appear to be soft and pink. The dead bighorn's lungs are firm and filled with pus.

"They look like someone took a baseball bat to them," Jourdonnais said. "You can just almost feel their pain just looking at it. It's a sad thing."

Ravalli Republic editor Perry Backus can be reached at 363-3300 or


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WEST RIVERSIDE - A pneumonia outbreak may spell doom for many of the bighorn sheep frequenting the West Riverside community east of Missoula. Montana Fish, Wildlife and Parks hunters have killed seven sick sheep since Tuesday and may have to take many more of the roughly 65 bighorns on Woody Mountain to interrupt spread of the highly infectious disease.

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