CASPER, Wyo. — A herd of bighorn sheep in the Gros Ventre Mountains near Jackson “has typically numbered approximately 500 animals,” the Wyoming Game and Fish Department says.
However, “two significant pneumonia die-offs in recent years” cut into the herd’s population.
“In 2002, it was estimated that as many as 50 percent of the herd was lost due to a pneumonia outbreak and another estimated 30 percent lost again in 2012,” Game and Fish says. “It is estimated that the herd has climbed back to around 400 animals currently.”
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“Other bighorn sheep herds across the Rocky Mountains have also experienced significant declines in populations due to pneumonia in recent years.”
In an effort to understand and possibly help prevent future die-offs, Game and Fish and the University of Wyoming collaborate to study bighorn sheep.
“Recently, 12 collared female bighorn sheep were captured for disease sampling, body condition measurements, and fitted with radio collars to learn more about their survival, nutritional condition, migration patterns and the potential presence of disease,” Game and Fish said on Dec. 23. “Samples were collected to test for respiratory pathogens that can cause pneumonia.”
“Researchers from the Haub School of Environment and Natural Resources and Wyoming Cooperative Fish and Wildlife Research Unit at the University of Wyoming performed an ultrasound on each animal to measure body fat, which showed the animals in good shape going into winter. This is part of a multi-year study evaluating how body condition is related to pneumonia outbreaks.”
Game and Fish shared the following photos from the capture and testing efforts: