Evaluating lek occupancy of Greater Sage-Grouse in relation to landscape cultivation in the Dakotas

摘要

Greater Sage-Grouse (Centrocercus urophasianus) have been declining in many states and provinces of North America, and North and South Dakota hold no exception to these declines. We studied effects of cultivated land on Greater Sage-Grouse lek abandonment in North and South Dakota. Landscape-level data were assessed using satellite imagery within a geographic information system. Comparisons were made of 1972-1976 and 1999-2000 pet-cent cultivated and noncultivated land. These comparisons were made between land uses surrounding active leks versus inactive leks, active leks versus random locations, and abandoned regions versus active regions. The 1999-2000 imagery illustrated that percent Cultivated land was greater near abandoned leks (4-km buffers) than near active leks in North Dakota or random sites, but this did not hold true in South Dakota. Comparison of an extensive region of abandoned leks with a region of active leks in North Dakota illustrated a similar increase as well as dispersion of cultivation within the abandoned region. However, 1972-1976 imagery revealed that this relationship between percentage of cultivated land and lek activity in North Dakota has been static over the last 30 years. Thus, if the decline of Greater Sage-Grouse is the result of cultivated land infringements, it occurred prior to 1972 in North Dakota.