Landscape-level analyses of Henslow's sparrow (Ammodramus henslowii) abundance in reclaimed coal mine grasslands

Henslow's sparrow (Ammodramus henslowii) abundance, measured as average num ber of males at point counts, varied within and among reclaimed mine grassl ands of southwestern Indiana. The 19 mine grasslands studied range from abo ut 100 to 3200 ha and vary in landscape structure and composition both with in the mines and in relation to the surrounding area. Nevertheless, few lan dscape-level attributes of mine grasslands were related to Henslow's sparro w abundance. Landscape composition (e.g., percent forest or grassland cover ), in particular, had a negligible effect on Henslow's sparrow abundance. N either habitat patch size nor shape had a significant effect on Henslow's s parrow abundance, but these birds tended to avoid habitat edges. Variation in Henslow's sparrow abundance was, however, influenced by the composition and structure of local vegetation. The relative "landscape insensitivity" o f Henslow's sparrows probably reflects the large area of mine grasslands ra ther than a true lack of landscape-sensitivity in this species.