ENTERPRISE, Ore. – Research is showing that Hells Canyon bighorn sheep range wide. “One ram with a conventional collar went to four different herds in three states,” said Vic Coggins, ODFW district wildlife biologist.
Wildlife personnel from the Hells Canyon Initiative captured 51 Rocky Mountain bighorn sheep in five different herds during the 2007-08 winter to take samples for ongoing disease research, recover GPS collars from some rams, and attach conventional radio collars to others as part of ongoing research into movement patterns and disease.
By understanding bighorn sheep movements between herds, biologists hope to better understand, and prevent, disease transfer. Movement data collected to date indicates Hells Canyon bighorn herds are connected, allowing both genetic and disease exchange among herds.
Bighorns captured were sampled for the bacterium that causes pneumonia (Mycoplasma ovipneumoniae), which experts believe may be the most important factor limiting bighorn herd growth in Hells Canyon. Five of seven live bighorns from the Lostine Herd, which lost most of its lambs in 2007, tested positive for the bacterium.
Mycoplasma ovipneumoniae is a small, difficult-to-detect bacteria found in domestic sheep and goats. The bacteria can also infect wild sheep, with fatal results, and is widespread in Hells Canyon bighorn sheep. Every effort is made to keep bighorns away from domestic sheep and goats in Hells Canyon to avoid disease transmission.
There is no vaccine for Mycoplasma ovipneumoniae but biologists are seeing positive results from their increased use of antibiotics. “We are seeing less coughing and nasal discharge in bighorns treated with the antibiotic,” said Coggins. “We are hopeful that the drugs will reduce bacterial levels in adults and result in improved lamb survival next year.” A total of 33 Lostine herd bighorns were treated with antibiotics during the winter’s capture effort.
The capture and research efforts are thanks to the Hells Canyon Initiative, a group formalized in 1997 to restore bighorns to the Hells Canyon area in Oregon, Washington and Idaho. All three state wildlife departments, the U.S. Forest Service, Bureau of Land Management and the Foundation for North American Wild Sheep (FNAWS) are members of the group. In addition, the Nez Perce Tribe, Confederated Tribes of the Umatilla, Oregon Hunters Association and chapters, FNAWS chapters, Shikar-Safari Club International and many individuals have provided funding or assistance with restoration efforts.
For photos of the capture effort, please email Michelle.N.Dennehy@state.or.us or call 503 947 6022