Agricultural land cover does not affect the diet of Tree Swallows in wetland-dominated habitats

Agricultural practices have intensified during the past 50 yr, increasing crop production and altering the Canadian prairie landscape by removing or degrading uncropped habitats, including wetlands. We predicted that agricultural practices would alter invertebrate communities and the diets of consumers such as insectivorous birds. Using stable isotope analysis (δ13C and δ15N), we tested for differences in the assimilated diets and isotopic niche...