Bird Communities of Res Tored Pr a Iries and Ol D-f Iel D Habitat S in Agricult Ur Al and Urban a Re as of W Inona Coun T Y, Minnesota

2 2 N D N O R T H A M E R IC A N P R A IR IE C O N F E R E N C E | P R A IR IE F L O R A A N D F A U N A Abstract: Native prairie and savanna habitats in southeastern Minnesota have been mostly eliminated by agriculture and urbanization. Resource management agencies and private landowners have idled former agricultural land and planted prairie vegetation or grassland cover on some sites to restore native plant and animal communities. The goal of this study was to survey bird communities in small (<10 ha) restored prairies and idled old-field habitats in agricultural and urban areas of Winona County, Minnesota. Six sites were surveyed five times each during one or two breeding seasons (May-August, 2008 and 2009). Perched or flushed birds along transects were identified and tallied to determine bird community structure and density. Over 900 birds representing 30 species were recorded during surveys, averaging 11 species/site (range = 7-19 species/site). Six generalist or woody-dependent species (American goldfinch, Carduelis tristis; red-winged blackbird, Agelaius phoeniceus; song sparrow, Melospiza melodia; indigo bunting, Passerina cyanea; chipping sparrow, Spizella passerine; house sparrow, Passer domesticus) were present at four or more sites, and represented >71% of all birds tallied. Species that strongly associate with grassland habitats (bobolink, Dolichonyx oryzivorous; dickcissel, Spiza Americana; field sparrow, Spizella pusilla; grasshopper sparrow, Ammodramus savannarum; ring-necked pheasant, Phasianus colchicus) represented only 8% of birds sighted and were found at only one or two sites each. Bird densities at most sites ranged from 13-17 birds/ha. Bird community diversity indices were similar at all sites, but bird community structure differed significantly (all Bray-Curtis similarity values <0.6) among all sites. Summer bird communities in small, restored grasslands and old fields of southeastern Minnesota appear to be highly variable and dominated by generalist and woody-dependent species, with grassland specialists present only in the larger (>3 ha) sites surveyed. Small grassland-habitat patch size and proximity of woody vegetation limited the attractiveness of grasslands in this region to native grassland birds. Key Words/Search Terms: bird diversity, community similarity, community structure, bird density, grassland birds