Occurrence of Burrowing Owls in black-tailed prairie dog colonies on Great Plains National Grasslands

The United States Department of Agriculture (USDA) Forest Service classifies the Burrowing Owl (Athene cunicularia) as a sensitive species on Great Plains National Grasslands, although no grassland-wide assessment had been conducted prior to the survey described here. During spring and summer 1998, most black-tailed prairie dog (Cynomys hulovicianus) colonies on National Grasslands were examined for the presence of Burrowing Owls. Of 582 colonies examined for Burrowing Owls, 444 (76%) showed signs of black-tailed prairie dog activity. Remaining colonies examined (N = 138) were inactive due to sylvatic plague (Yersinia pestis), shooting, or poisoning. We observed Burrowing Owls at 322 (55%) of the 582 colonies: owls were detected on 307 (69%) of 444 active colonies and 15 (11%) of 138 inactive colonies. Among National Grassland units, the percentage of colonies occupied by owls ranged from 16-93%. Burrowing Owl occupancy of active black-tailed prairie dog colonies was higher in the southern Great Plains (93%) than in the northern Great Plains (59%). National Grasslands occur primarily in the western Great Plains from North Dakota to Texas and encompass approximately 1.5 million ha of short- and mixed-grass prairie, most of which is potential habitat for black-tailed prairie dogs. Of this potential habitat, prairie dog colonies currently occupy 17 075 ha. Thus, there is substantial National Grassland area for prairie dog colonies to increase and provide additional nesting opportunities for Burrowing Owls.