JACKSON, Wyo. — The Wyoming Game and Fish Department (WGFD) has premiered a 12-minute video exploring the history and management of bighorn sheep in Wyoming.
The documentary-style short, Carrying Capacity, discusses how population size can impact the health of a herd. The term “carrying capacity” is the maximum population size that an environment can sustainably support over time. The film focuses on the Jackson herd and the Ferris Seminoe herd.
As detailed in the video, the Jackson sheep form a native herd; meaning that they are direct descendants of the sheep that have been living in this area since the last ice age. The herd was estimated to have 1,000 sheep in the 1930s, before going through a pneumonia die-off that killed 90% of the herd. Since then, the herd has experienced similar outbreaks every 10 to 20 years, with the most recent pneumonia die-off taking place in the early 2000s.
The Ferris Seminoe herd, north of Rawlins, is composed of reintroduced sheep on once-occupied habitat. According to the scientists and wildlife managers in the video, it is the only herd in Wyoming that is largely free of pathogens and disease. However, when a herd surpasses its carrying capacity, male bighorn sheep will sometimes strike out on their own, and they risk infecting the herd with new pathogens if they return.
The film features observations from scientists, wildlife managers and hunters that highlight the roles of hunting and disease in management throughout the state.
“To maintain sustainable population levels within each of the herd’s carrying capacities, Game and Fish has implemented ewe/lamb hunts,” WGFD wrote in a press release announcing the video. “This management strategy is a proactive and innovative approach to protect the health and long-term viability and sustainability of bighorn sheep populations.”
WGFD is planning in-person screening events with discussion panels for the spring. Details will be announced at a later date.
