Date of this Version
The Prairie Naturalist 47:30–39; 2016
The bighorn sheep (Ovis canadensis canadensis) herd occupying the Elk Mountain Region of South Dakota and Wyoming was established in 2001 with 20 individuals. An additional 7 ewes were released in 2004. The population increased to approximately 120 individuals in 2009, but subsequently declined to an estimated 80 individuals. Because of the low population size used to establish the herd and relative isolation of the Elk Mountain Region, potential factors associated with the population decline included reduced genetic diversity. Our objectives were to: 1) assess genetic diversity, 2) measure effective population size (Ne), and 3) compare the genetic diversity of Elk Mountain bighorn sheep to other native and translocated herds throughout the United States. Genetic analysis was conducted on DNA from 43 unique samples collected from bighorn sheep on Elk Mountain between 2012 and 2014, using 15 microsatellite loci. When compared to other populations, our results indicated the Elk Mountain bighorn sheep herd had levels of genetic variation similar to healthy native herds. Additionally, Ne/N for the herd fell within values reported for other healthy bighorn sheep populations. Nevertheless, further genetic evaluation is recommended for all Black Hills bighorn sheep herds.