The social calls of bats are an area about which relatively little is known, with more research still required to expand our understanding. However, these calls are increasingly recognised as a useful aid to identification: they appear to be species specific and are indicative of behaviour - as in territorial activity of males during the mating season. Because the gathering and interpretation of bat echolocation data are a matter of course during research, conservation and consultancy, it is a logical progression to build momentum behind the consideration of social calls in mainstream bat-related work. A better understanding of this subject could mean that non-intrusive survey methods are developed, ensuring that what is being observed is, as far as possible, purely natural behaviour. In turn this will contribute to better interpretation and more suitable mitigation, compensation and/or enhancement solutions. The book summarises what is understood so far about social calls of the bat species occurring in Britain and Ireland, and north-west Europe. This new edition has been updated and expanded throughout, now containing: foreword by the bat authority Michel Barataud, author of Acoustic Ecology of European Bats almost double the number of figures and tables as appeared in the first edition completely overhauled call library, all in full spectrum format, with new additional examples three entirely new chapters, covering bat-related acoustics, settings for social interaction, and survey guidelines The material will be useful to people carrying out bat studies, at whatever level and for whatever purpose, and will also encourage others to undertake further research. What's more, social calls are fascinating to listen to: they are, after all, produced with listeners in mind (other bats). In light of this, the book is accompanied by an extensive downloadable library of sound files which offer a unique gateway into the private life of bats.