Evaluation of the Deadwood Bighorn Sheep Herd Translocation

From 2015-2017, we evaluated a newly established bighorn sheep (Ovis canadensis) herd in the Deadwood Region of the Black Hills, South Dakota. Our objectives were to 1a) determine annual survival rates, 1b) determine cause-specific mortality, 1c) estimate population size, 2a) assess genetic diversity, 2b) assess disease prevalence, 3) evaluate movement patterns post-release, 4a) evaluate 3rd-order habitat selection, and 4b) estimate herbaceous biomass at foraging sites post-release of translocated bighorn sheep. In February 2015, we captured and translocated 26 bighorn sheep from the Luscar Mine near Hinton, Alberta, Canada to the Deadwood Region of the Black Hills, South Dakota. Overall annual bighorn sheep survival rates were 64.4% (95% CI=0.48-0.77). Confirmed pneumonia accounted for 57.9% (n=11) of all cause-specific mortalities, while no predation was documented during the study. We estimated the population size at the end of the study period was 24 bighorn sheep (λ=0.92). Observed and expected heterozygosity were 0.71 (SE=0.06) and 0.64 (SE=0.05), respectively. The Mycoplasma ovipneumoniae pathogen found within the Deadwood bighorn sheep herd was of a strain type previously undocumented in the Black Hills. Dispersal among individual bighorn sheep occurred year 1, while establishment of home-ranges occurred year 2. We used 95% Brownian Bridge Movement Models for year 2, which resulted in a mean homerange size of 5.29 km2. Forested habitat was actively avoided (ŵ=0.30), while barren (ŵ=16.93), shrubland (ŵ=1.28), and grassland (ŵ=1.65) habitats were selected. Foraging sites were typically located in areas with little overstory tree canopy cover (mean= 8.41%, SE=1.85), short distance to escape terrain (mean= 24.00 m, SE=3.21), and little woody debris (mean= 0.25 kg/ha, SE=0.07). Herbaceous biomass ranged from 302.07 kg/ha to 2,487.43 kg/ha. Our results indicate that the Deadwood Region of the Black Hills, South Dakota had sufficient forage and habitat capabilities to support a healthy population of bighorn sheep. Translocations to this region can be successful, however, pneumonia, caused by the Mycoplasma ovipneumoniae pathogen, was the greatest limiting factor to population growth within the Deadwood bighorn sheep herd