Private land conservation has landscape-scale benefits for wildlife in agroecosystems

Private lands contain much of the world's biodiversity. Conservation of private land, especially agricultural land, is urgent yet challenging because of the diverse priorities of landowners. Local effects of farmland conservation programmes have been evaluated thoroughly, but population-level response to these programmes may depend on effects that extend beyond targeted land parcels. We investigated the landscape-scale effects of a grassland conservation initiative, the Conservation Reserve Enhancement Program (CREP), on a socially and economically important gamebird, the Northern Bobwhite (Colinus virginianus). Barriers to assessing population-level response to conservation include determining the spatial scale at which a species responds to environmental change (the scale of effect) and untangling density-dependent processes. We performed point counts over 6 years at 247 sites with similar local CREP density but varying landscape-scale CREP density. We used an open-population distance...