The Effects of Agricultural Intensification on An Obligate Grassland Bird of North America

Grassland birds are in decline worldwide and the leading cause of this decline is habitat loss and degradation through agricultural intensification. The purpose of this study is to investigate the impacts of agricultural intensification on a declining grassland bird, the Savannah Sparrow (Passerculus sandwichensis). Over two breeding seasons nests were located and monitored, adults and nestlings were measured to assess body condition, and fledglings were manually radio tracked to quantify survival. Nesting success over the two-years was significantly lower on agricultural sites. However, nest predation was higher in agricultural sites in only one of the two years, fledgling survival was not significantly different, and no differences were found in the nest productivity, nor body condition of adults and nestlings. Long-term monitoring is needed to determine if nest predation is consistently higher in intensive agriculture, but at present our results indicate that in some years intensive agriculture may provide adequate habitat.