Relation of grassland bird abundance to mowing of Conservation Reserve Program field in North Dakota

One factor that may be contributing to declines of several grassland bird s pecies is mowing of grassland fields. We compared the relative abundance of birds in idled and mowed portions of grassland fields to investigate the i nfluence of mowing in the previous summer on the grassland bird community. The study occurred in central North Dakota in 12 reseeded cropland fields e nrolled in the Conservation Reserve Program. Sedge wrens (Cistothorus plate nsis) were more abundant in idled portions of grassland fields, whereas sav annah sparrows (Passerculus sandwichensis) were more abundant in portions o f fields that were mowed the previous year. Our findings are similar to oth er studies indicating that several grassland bird species in the central Un ited States and Canada respond consistently to mowing.