Distribution and Abundance of American Martens and Cougars in the Black Hills of South Dakota and Wyoming

American martens (Martes americana) and cougars (Puma concolor) are 2 carnivores that have become reestablished in the Black Hills of South Dakota and Wyoming. I predicted current distributions and estimated population sizes for both species in the Black Hills. Using geographical information system technology, I constructed and tested ranked habitat-relation models for martens and cougars in the Black Hills National Forest to predict their current distributions. For martens, I modeled the population and spatial structure using data derived from a marten habitat-relation model a track-plate box population survey, a sample of radiocollared martens (n = 13), and a marten Habitat Suitability Index model. I estimated the resident adult population size of martens based on mean home range size of radiocollared martens in high-quality habitat patches. Cougar population size was estimated using a population program, incorporating parameters obtained from radiocollared cougars (n = 12), the literature, and habitat quality derived from the cougar habitat-relation model. Results indicated the American marten distribution in the Black Hills coincided with white spruce-dominated (Picea glauca) forests and associated contiguous forests of other types (predominantly ponderosa pine, Pinus ponderosa). High-quality marten habitat consisted of mature, dense canopied (\u3e50%), spruce-dominated forests, in riparian areas, and at relatively high elevations. The marten population in the Black Hills was distributed in a metapopulation structure, containing 2 subpopulations; a 246-km2 area in the northern Black Hills and a 121-km2 area that included the Norbeck Wildlife Preserve and vicinity in the central Black Hills; marten presence was lower intermediate to the 2 subpopulations where spruce-dominated forests were more fragmented. Based on mean home range sizes (15.8 km2 for males, and 5.8 km2 for females) of radio-collared martens, 124 resident adult martens were estimated to occur in 492 km2 of high-quality habitat patches. High-quality cougar habitat (6,702.9 km2; based on macro-habitat characteristics of prey, stalking topography, and concealment habitat) occurred throughout the Black Hills. However, the distribution of the highest ranked habitats was not uniformly distributed, suggesting densities of cougars varied locally within the Black Hills National Forest. Mean annual home-range size of 3 established adult male cougars (n = 9 annual ranges) was 809.2 km2, and was significantly larger (P = 0.001) than that of adult females (n = 7 annual ranges, 182.3 km2). Three and 5 females were documented in home ranges of 2 adult male cougars. Total number of cougars in the Black Hills was estimated as 127–149, with an estimated carrying capacity of 152 cougars. A minimum of 5,277 km2 of high-quality habitat was necessary to maintain the cougar population long-term