Abstract

Bats are fascinating mammals about which we still have much to learn. As well as using ultrasonic echolocation calls for orientation and while foraging, they also have a complex array of vocalisations for communication. These are known as social calls and are an essential component of their colonial lifestyle.

This book brings together the current state of knowledge of social calls relating to the bat species occurring within Britain and Ireland, with some additional examples from species represented elsewhere in Europe. It includes access to a downloadable library of calls to be used in conjunction with the book.

Downloadable call library 
Social calls are complex and intriguing to listen to; they are after all produced with listeners in mind (other bats). To enjoy and fully appreciate social calls the reader must also have the opportunity to become a listener: each of the presented sonograms in the book is cross-referenced to downloadable ‘time expanded’ .wav sound files which are contained within a much wider library of calls for you to explore.

Included in Social Calls of the Bats of Britain and Ireland 
The authors start with an overview of the species of bats in Britain and Ireland (Chapter 1), and then introduce us to communication within the social world of bats (Chapter 2). Referencing the latest research, the authors explore how these calls can be classified according to their structure, and in many cases the context in which the calls are thought to be emitted (Chapter 3). Chapter 4 addresses aspects of survey methodology to be considered by those studying social calls. This leads on to the analysis of calls (Chapter 5), detailing the specific methods used and parameters commonly measured by researchers.

The final, and main chapter (Chapter 6) introduces the 23 species covered in the book giving each a detailed profile including: habitat preferences, typical roosting locations, roost emergence times, mating strategies and maternity behaviour. Each species profile includes what is known about the social calls for that species and this text is supported by colour sonograms (created using Pettersson BatSound V4.1) of most of the calls discussed. Each sonogram is linked to a .wav sound file (Time Expansion x10) within the downloadable library. The sound files allow the reader to hear, as well as see, the calls produced using any bat sound analysis software that supports the .wav format.

The authors conclude with a bibliography and an extensive list of references directly cross-referenced throughout the book.

Neil Middleton is a licensed bat worker and trainer, with 20 years experience, having carried out most of his bat related work within the UK and Europe (Ireland, Cyprus, France, Spain and Hungary).  He is the managing director of Echoes Ecology Ltd (www.echoesecology.co.uk), an ecological consultancy he established in Scotland during 2006.  Neil has been involved with many bat related projects to date, including the Bats & The Millennium Link (BaTML) project which he set up to study the use of canal corridors by bats in Scotland (www.batml.org.uk).  Neil is an accomplished trainer across a wide range of bat related subjects, having developed and delivered well over a 100 events to date.  Neil first came across his co-authors, Andrew and Keith, whilst they all attended a bat course in Somerset during 2004, an event that not only inspired all three of them, but also was the beginning of a long friendship as they explored many bat related subjects together, including the material for this book.

Andrew Froud is an ‘Ecologist’ working for the City of London, within Epping Forest (Essex).  He is a licensed bat worker with over 10 years experience.  In 2006, together with Keith French, he set up a 6 year research project, within a small part of Epping Forest, to examine habitat usage by bats in conjunction with the impact of habitat changes brought on by the sites Conservation Management Plan.  Andrew’s initial interest in social calls came about when he and Keith discovered the first known lekking Nathusius’ pipistrelle roosts for Essex on their site.  Since then, he has been fascinated by the subject, and recorded many social calls across a wide range of species.  In recent years Andrew has delivered presentations on this subject to course delegates, local bat groups and natural history groups.

Keith French has over 10 years’ experience with bat related work, and is a licensed bat worker, both living and working within Epping Forest (Essex), where he is employed by the City of London as ‘Head Forest Keeper’.  Having a driven associate like Andrew Froud has helped fuel his enthusiasm to delve deeper into this complex and relatively un-researched subject.  After recording their first Nathusius’ pipistrelle lekking in an ancient oak pollard, the search was on to record social calls from other species, especially Noctule and Myotis.  Keith has also been keen to pass on the knowledge he has gained by giving guided walks, presentations and allowing volunteers the chance to improve their skills.  He is well travelled, having been fortunate enough to observe and record bats in some exotic locations such as the Amazon, Croatia, Costa Rica, USA and several African countries.