Grassland management for the conservation of songbirds in the Midwestern USA

We monitored breeding eastern meadowlarks, dickcissels, Henslow's sparrows, grasshopper sparrows and field sparrows using strip transect surveys in 19 95 and 1996. The 473-ha study area was an array of 3-ha management units of burned, mowed, hayed, grazed and undisturbed (> 1 year) cool- and warm-sea son grasses and annual weeds. Management units grouped by habitat type (man agement regime and grass type) had different (P < 0.05) abundances of each species. Eastern meadowlarks and dickcissels were most frequently observed in grazed warm-season grasses. Observation rates of Henslow's sparrows and field sparrows were highest in undisturbed warm-season grasses, whereas eas tern meadowlarks and grasshopper sparrows were observed least often in this habitat type. Grasshopper sparrows were observed most frequently in annual weeds; Henslow's sparrows and field sparrows were not observed in this hab itat type. Overall avian abundance was lowest in recently burned cool-seaso n grasses. The low-intensity, late-season grazing system was important for creating a heterogeneous habitat mosaic attractive to the five species stud ied. (C) 2000 Elsevier Science Ltd. All rights reserved.