At least 20 bighorn sheep living in Riverside County’s San Gorgonio desert have died recently, prompting state officials to launch an investigation into what’s causing the sudden uptick in mortality.
Though authorities have only been able to confirm 20 deaths, they suspect more of the sheep have succumbed after contracting a respiratory disease, the California Department of Fish and Wildlife said in a Friday news release.
“Our top priority right now is to determine the source and nature of the disease so that we can identify the right management actions to mitigate future risk,” Heidi Calvert, an environmental program manager for the department’s inland deserts region, said in a statement.
The agency first became aware of the sick sheep in December. Officials immediately began collecting samples for lab analysis, and there are ongoing efforts to monitor the population to assess the magnitude of the issue.
Jeffrey Villepique, a wildlife biologist with Fish and Wildlife, told the Desert Sun that pneumonia transmitted from domestic sheep or goats is the most likely cause, but other possible sources are being looked into.
Villepique told the newspaper the bighorn population appears to have thinned to less than a third of its usual size based on what he’s seen hiking in the area in the past several weeks.
Fish and Wildlife said the die off is centered near the town of Whitewater, within its Desert Bighorn Sheep Hunt Zone 5, and will likely result in no hunting tags being distributed in the zone this year.