Land cover associations of nesting territories of three sympatric buteos in shortgrass prairie

Three species of Buteo hawks nest sympatrically in the southern Great Plains of the United States. Dietary overlap among them is broad and we tested the hypothesis these species partition their breeding habitat spatially. We compared land cover and topography around 224 nests of the three species breeding in shortgrass prairie in 2004 and 2005. Red-tailed Hawks (Buteo jamaicensis) nested almost exclusively in riparian timber surrounded by prairie (95% prairie land cover around nests) and disproportionately used areas with greater topographic relief within prairie landscapes. Swainson's Hawks (B. swainsoni) commonly nested in low-relief areas dominated by small-grain production agriculture but generally used habitats in proportion to availability. Most nest sites of Ferruginous Hawks (B. regalis) were in prairie (78% prairie land cover around nests), but some were in areas that were at least partially agricultural. Ferruginous Hawks had at least two times more sand sagebrush (Artemisia filifolia) around their nests than their two congeners. We conclude that sympatric breeding Buteos on the southern Great Plains spatially partitioned nest sites according to subtle differences in land cover and topography.