Capture and Translocation of Mountain Sheep

We discuss the importance of the capture and translocation to the conservation and management of mountain sheep (bighorn [ Ovis canadensis ], thinhorn [ Ovis dalli ]). Native Americans used mountain sheep as a source of protein and tool making such as horn bows. Today, the capture of mountain sheep is done as a matter of science and management. The capture and translocation of mountain sheep is used as a management tool to better understand their ecology and to restore them throughout their historic range. Several techniques have been developed to capture mountain sheep. Today, chemical immobilization, drop-netting, and helicopter net-gunning are the most common and effective methods. Each technique has advantages and disadvantages, and consideration must be given to personnel safety and minimization of injury or mortality to the mountain sheep captured. Since 1922, at least 1,460 separate projects have resulted in the translocation of more than 21,500 bighorn sheep in the United States and Canada combined. More than 1,300 wild sheep have been translocated across international boundaries from Canada and Mexico into 14 United States jurisdictions. The roots of today’s bighorn populations in several states can be traced entirely to translocations. The greatest lessons learned by biologists from translocations are: matching the source population of mountain sheep to habitats they are familiar with and most adapted to; predation of naïve mountain sheep in a new environment that can be significant and must be addressed; translocations of mountain sheep, in the face of ever-increasing prevalence of pathogens that cause disease in mountain sheep, must be considered when and where translocations occur. We encourage readers to further explore the early history of capture and translocations while keeping pace with ongoing advances and developments, and to apply information as appropriate and in the best interest of the conservation and management of mountain sheep.