Bighorn sheep are no strangers to disease. Over the past few decades, herds have experienced massive die-offs, resulting in careful monitoring and, unfortunately, euthanasia to protect wild herds when wildlife biologists discover they have come into contact with domestic sheep. While relocation efforts have mostly been successful, the key issue remains unsolved: why does this disease cause so much devastation in wild herds?
Researchers at Oregon State University are after an answer and are concentrating efforts on roughly 3,700 California bighorn sheep that call Oregon home. They are studying movement, habitat use and survival rates in order to determine an animal’s risk to contracting the fatal strain of bacterial pneumonia – known as M.ovi (short for Mycoplasma ovipneumoniae), according to KTVZ.com.
“There is a high-stakes need to understand where the pathogen is likely to enter a bighorn population and where it’s likely [to] move after that,” OSU wildlife biologist Clint Epps told KTVZ.com. “In the past few years, wildlife agencies in the West have made decisions to remove certain individual animals, or all individuals in the herd, to prevent the spread of disease.”
So far OSW biologists and veterinarians have collared 120 bighorn sheep over the past two years to track each animal’s movements as well as its mortality.
“We’re able to respond to mortalities, and we are able to determine cause of death in most cases,” Robert Spaan, an OSU doctoral student told KTVZ.com. “We managed to detect a die-off of lambs in one population last year, the only one where we saw active M. ovi infection.”
Because of the severity of the disease and the complexities of the study, the state is holding off on further relocation efforts while the research continues. Perhaps, it will shed new light on the disease and offer ways that biologists can try to manage it in the future.
“There’s been a tremendous amount of effort to increase these bighorn populations, and our goal is to provide better information when they make those decisions,” says Epps.