Common Nighthawks (Chordeiles minor) in the Western Corn Belt: Habitat Associations and Population Effects of Grassland and Rooftop Nesting Habitat Conversion

Abstract Grassland habitat in the Northern Prairie region of North America has been greatly reduced since historical times, and conversion to agricultural row-crop production has recently intensified this decline. Common Nighthawk (Chordeiles minor) nesting habitat includes grasslands and flat, gravel rooftops, but relative occurrence of nighthawks in these habitats in the Northern Prairie region has not been previously quantified. We conducted point counts at 396 sites within two study areas in South Dakota, Nebraska, and Iowa; an eastern region dominated by row-crop agriculture and a western region with more grassland within the landscape. We compared land cover at points where nighthawks were present between the two regions and found higher incidences of cropland and grassland in the western region and higher developed land cover in the eastern region. We also compared land cover surrounding points where birds were present vs. absent for both regions combined and found greater cropland around points wi...