Breeding Bird Communities Associated With Tallgrass Prairies in Southeast Nebraska

39 Introduction Within Nebraska, the Tallgrass Prairie Ecoregion occupies the approximate eastern one–third of the state and was historically characterized by extensive grassland habitats with scattered areas of upland deciduous forests and savannas, and lowland prairie or deciduous forests along riparian drainages (Kaul et al. 2011, Schneider et al. 2011). A nearly complete conversion of tallgrass prairie habitats in Nebraska to agricultural production has resulted in perhaps less than one percent of the historic amount remaining into the 21 st century (Kaul et al. 2011, Schneider et al. 2011). Remaining tallgrass prairie habitats are often small and isolated from other remnants, experiencing encroachment by woody plants and invasion by exotic species, and subjected to land management activities such as grazing and haying that are focused on economic objectives without consideration of biodiversity objectives (Fitzgerald and Pashley 2000, Schneider et al. 2011). These landscape changes have had deleterious effects on many species of Nebraska flora and fauna, necessitating conservation actions. The Nebraska Natural Legacy Project (NNLP) identified a number of Biologically Unique Landscapes where focused conservation activities should be most effective at conserving the state's biodiversity (Schneider et al. 2011). Two of the Biologically Unique Landscapes (BULs), the Sandstone Prairies BUL and the Southeast Prairies BUL, are encompassed by the Tallgrass Prairie Ecoregion in Nebraska and were the locations of our study. For decades, grassland birds have exhibited some of the steepest and most consistent declines of any group BUL, four species of grassland birds are identified by the NNLP as Tier I species (species that are at–risk both globally or nationally and at risk of being extirpated from the State of Nebraska; greater prairie–chicken, log-gerhead shrike, Bells's vireo, and Henslow's sparrow). Other regional bird conservation plans that address the geographic area represented by the Sandstone Prairies BUL and Southeast Prairies BUL categorize these four species as well as three additional grassland bird species (dickcissel, field sparrow, and bobolink) as priorities for conservation action (Fitzgerald and Pashley 2000). As part of a larger study examining the interaction of fire and cattle grazing in southeast Nebraska tallgrass prairies (Fuhlendorf et al. 2013), we collected data on relative abundance of birds at multiple sites in the Sandstone Prairies and Southeast Prairies BULs during the breeding seasons of 2010–2011. Our data represent a valuable contribution to Nebraska ornithology by providing information on two areas of the state where conservation attention has been prioritized and …