Pneumonia outbreak cut bighorn herds in half

A pneumonia epidemic killed about half the wild bighorn sheep around Bonner and Rock Creek this winter, and left biologists with plenty to ponder this spring. "What was amazing to me was how lethal this outbreak was and how fast it spread," said Ray Vinkey, a wildlife biologist with the state Department of Fish, Wildlife and Parks who monitored the outbreak in Rock Creek. And there's growing evidence those sheep shared the same disease with herds around Bonner and West Riverside - roughly 40 miles to the west. This winter also gave biologists a rare chance to make side-by-side-by-side comparisons of three response tactics. FWP wardens and biologists shot 95 sick sheep in the hills north of West Riverside, hoping to keep the contagious disease from spreading to herds farther north in the Rattlesnake Wilderness and Blackfoot River corridor. But in Rock Creek, where there are distinct herds in the lower and upper parts of the drainage, biologists collected a few sick animals for tissue samples but didn't do any aggressive culling. Geography dictated part of that response: Sheep are hard to reach in the steep crags of Lower Rock Creek, while the open rolling grasslands of the upper drainage made it impossible to isolate sick animals from healthy ones. The third response took place east of Darby last November when another pneumonia outbreak ravaged the herd there. FWP shooters quickly killed 77 infected sheep but spared neighbors that weren't showing symptoms...more