Effects of the Arable Stewardship Pilot Scheme on breeding birds at field and farm-scales

In the short- to medium-term, agri-environment schemes are potentially the key mechanism for reversing farmland bird declines across Europe. The Arable Stewardship Pilot Scheme (ASPS) was designed to test the delivery of resources by a suite of management options for a range of farmland taxa, in two lowland farmland regions of England (East Anglia and West Midlands). The impact of ASPS on breeding farmland birds was tested in a replicated farm-scale experiment, in which changes in numbers of breeding birds over 5 years were compared between scheme and control farms. Additionally, the impact of specific ASPS options on breeding bird distribution was assessed at the field-scale, using data collected after the options had been deployed for 5 years. At the field-scale, presence/absence of both field nesting and boundary-nesting species was associated with the presence of certain ASPS options. Many of these responses can be explained in terms of abundance of/access to nest sites or invertebrate/seed food resources provided by the ASPS options. However, despite showing significant positive responses at the field-scale, most species showed no response at a farm-scale. Between-year changes were significantly more positive on scheme than control farms for only three species in East Anglia and one species in West Midlands. The importance of these results is discussed with respect to the value of further research on the scale of options required to produce farm-scale effects.