Throughout Europe, many species of bats experienced serious population declines during the last century. Bats have been affected by the same pressures that have caused the decline of many other taxa, for example, agricultural intensification, habitat fragmentation and land-use change. There have also been specific additional pressures, such as the widespread use during the 1970s and 1980s of timber treatments which had high mammalian toxicity, and the deliberate or accidental exclusion of bats from their roosts. The conservation of bats has been particularly challenging because they are difficult to study, hence many of their complex ecological requirements have been discovered only recently or remain uncertain. A further obstacle was the general unpopularity and misunderstanding of bats among the public, such that deliberate killing of bats at their roosts was once very common. The introduction of legislation to protect bats has been pivotal in improving the status of the group, both directly and indirectly, by inspiring the interest of professionals and amateurs.

This chapter introduces the bats of Britain and Ireland and provides an overview of their ecological requirements. We review the evidence for population declines and focus on two major pressures, agricultural intensification and timber treatment. We then explore the ways in which the conservation infrastructure has been improved for bats and how a handful of committed specialists has become a large, skilled network. Case-studies illustrate how science has underpinned the development of policy for ‘flagship’ species, such as the Greater Horseshoe Bat and the implementation of landscape-scale conservation projects. […]