Livestock grazing impacts upon components of the breeding productivity of a common upland insectivorous passerine: results from a long-term experiment

The intensity of pastoral management in areas of High Nature Value farming is declining in some regions of Europe but increasing in others. This affects open habitats of conservation concern, such as the British uplands, where bird species that benefit from low-intensity grazing may be most sensitive to such polarisation. While experimental manipulations of livestock grazing intensities have improved our understanding of upland breeding bird responses in the short-term, none have examined the longer-term impacts of altered management on reproductive success.
Using a replicated landscape-scale experiment that started in 2003, we investigated the effects of four grazing treatments (intensive sheep; low-intensity sheep; low-intensity mixed sheep and cattle; and no grazing) on the breeding productivity of meadow pipits Anthus pratensis, the most common upland passerine. Surveys were carried out systematically during early (2003 & 2004) and later (2015 & 2016) sampling periods o...