Does habitat fragmentation influence nest predation in the shortgrass prairie?

We examined the effects of habitat fragmentation and vegetation structure o f shortgrass prairie and Conservation Reserve Program (CRP) lands on predat ion rates of artificial and natural nests in northeastern Colorado. The CRP provides federal payments to landowners to take highly erodible cropland o ut of agricultural production. In our study area, CRP lands have been resee ded primarily with non-native grasses, and this vegetation is taller than n ative shortgrass prairie. We measured three indices of habitat fragmentatio n (patch size, degree of matrix fragmentation, and distance from edge), non e of which influenced mortality rates of artificial or natural nests. Veget ation structure did influence predation rates of artificial nests; daily mo rtality decreased significantly with increasing vegetation height. Vegetati on structure did not influence predation rates of natural nests. CR-P lands and shortgrass sites did not differ with respect to mortality rates of art ificial nests. Our study area is only moderately fragmented; 62% of the stu dy area is occupied by native grassland. We conclude that the extent of hab itat fragmentation in our study area does not result in increased predation in remaining patches of shortgrass prairie habitat.