The effect of a Welsh agri-environment scheme on bat activity: A large-scale study

Agricultural intensification was a major driver of declines in western European wildlife populations during the twentieth century, including those of bats. Agri-environment schemes are advocated as the key government-funded mechanism to restore biodiversity, but evidence for their effects has been mixed. We examined the response of six bat species to Tir Gofal (TG), a Welsh AES that operated from 1999 to 2011. A large-scale multi-site study compared bat activity and key habitat variables on TG farms paired with control farms not in the scheme. Observations were made over three years (2009 to 2011) using three types of bat detector survey. Pipistrellus pipistrellus, P. pygmaeus, Myotis daubentonii, Rhinolophus hipposideros and R. ferrumequinum showed similar overall and foraging activity on TG and control farms (occurrence, intensity of activity where present). Occurrence of Nyctalus noctula and Nyctalus group was also similar on both farm types, but where they were present, the intensity of their activity was higher on control farms. The lack of influence of TG status on bat activity may reflect the close similarity in occurrence and condition of many key habitats on the two farm types and should be seen in the context of a mainly traditional extensively farmed landscape. Habitat prescriptions may have been insufficiently mature, implemented at too low density or lacking roosting provision to stimulate a species response, or may have had greater impact in a more intensively farmed landscape where less high quality bat habitat was available. A more targeted approach to creating and enhancing field and landscape scale roosting, foraging and commuting resources may be needed to effect positive responses in bat populations.