The Wyoming Game and Fish Department is continuing its research of the health of bighorn sheep in Jackson Hole. Last month, ten female sheep were captured and samples taken to analyze them for disease. Since 2011, the department says a total of 29 ewes have been collared, and only 19 are still alive. Spokesman Ray Hageman says many of the sheep have been stricken with pneumonia. Hageman points out that the Jackson herd typically numbers around 500 animals, but about 50% of the herd died off in 2002 because of a pneumonia outbreak, and another 30% were lost again in 2011 after the herd numbers had begun recovering. Hageman says laboratory results from sheep that have died in the past indicate the sheep have had Mycoplasma ovipneumoniae, which has contributed to other bighorn sheep die-offs across the West. Consequently, the researchers want to know how migration to other areas may lead to the sheep intermingling and spreading disease between herds.