Effects of Predators and Cattle on Ground-Nesting Grassland Birds in Southwestern Wisconsin Pastures;Master's thesis

摘要

North American grassland bird populations have seen dramatic declines over the past 30 years. Declines have been largely attributed to the loss of native and secondary grassland habitat for agricultural land use. Resulting habitat fragmentation may increase nest predation rates near edges. However, there is surprisingly little information about how various predators use different habitat edges or which predators depredate grassland bird nests. The purpose of this study was to determine if potential and known predators active along pasture edges differentially used woody or non-woody edges, and to positively identify grassland bird nest predators in pasture systems. Pastures located in southwestern Wisconsin were studied in 2000 (n = 10) and 2001 (n = 9). Track stations were placed on a woody and a non-woody edge surrounding each pasture to determine if individual species differentially used either edge type. Sixteen different species were documented in the track stations.