Bighorn sheep experience massive die-off in Wyoming

Disease has hit the Devil’s Canyon bighorn sheep herd in Wyoming. This week, the Wyoming Game and Fish Department (WGFD) reported that a strain of bacteria that causes “lethal pneumonia” has already killed at least 37 members of the herd, according to Oil City News.

“Since Oct. 14, Game and Fish has documented 37 bighorn sheep mortalities in the Devil’s Canyon herd, which constitutes approximately 10 percent of the population,” said Corey Class, wildlife management coordinator for the Cody Region. “The majority of deaths have occurred in ewes and lambs.”

WGFD was notified of the die-off within the herd by a landowner along with a mortality signal from a member of the herd outfitted with a GPS collar. 

“We have been working closely with a local landowner who has been key to managing and monitoring this disease outbreak,” said Class. “We greatly appreciate their assistance and cooperation.”

While the disease has been confirmed by the WGFD Wildlife Health Laboratory, how it came to infiltrate the wild herd is still unknown. For now, biologists are monitoring the herd through the 24 members outfitted with GPS collars. Carcasses of the dead animals have been properly disposed of to limit the spread of disease.

“The collars will now help us monitor bighorn sheep populations from a disease perspective and document additional mortalities,” said Class.

According to Oil City News, the Devil’s Canyon herd numbers about 250 to 300 animals. It is located in Hunt Area 12, which falls within the northwest portion of the Bighorn Mountains. 

“Our limited experience with this pathogen gives us some hope the outbreak will run its course quickly, with minimal mortalities,” said Hank Edwards, Wildlife Health Laboratory supervisor.