Social Calls of the Bats of Britain and Ireland

The scope of this book is to review the social calls of the 17 endemic and six vagrant species of bats in the UK and Ireland. The authors explain the difference between the classification of ‘echolocation’ calls of bats for the purposes of foraging, navigation and reducing exposure to predation, from the range of ‘social’ calls and describe the reasons both how and why bats communicate at the species and interspecies level socially.

The scope of the book to focus on ‘social’ communication is both ambitious and evolutionary. In the foreword Dr Sandie Sowler MCIEEM recognises the importance of this work to inform and educate on a little understood area of communication among bats. She hopes that this will encourage further research into this area for the improvement in understanding the behaviour of bats.

The book has many Spectogram graphics for the social calls of each species in various situations, and provides access to an online resource for audio and electronic files. This facility will be of use to anyone interested in listening to the fascinating range of bat calls. I recommend this book to all students, professionals and amateurs interested in developing their knowledge with this fascinating group of mammals.

-- Alan Linsdell * Mammal News *

Acoustic studies of bats have been increasing steadily since the 1980s; but it is studies of echolocation calls that constitute the majority of published work to date. With this book (accompanied by a sound library) Neil Middleton and his two colleagues contribute to filling in an obvious gap in the area of social calls emitted by European bats. So far, except for some papers limited to the description of social calls of a particular species, the thesis in German by Pfalzer (2002) and the article by Pfalzer and Kush (2003) were the main descriptive references. The authors have an experience of 10–20 years in the study and conservation of bats across Europe. They are the main contributors to this sound library with further contributions by some twenty or more people.

A brief first part (Chapter 1) presents, through the use of summary tables, the species occurring in Great-Britain and their biology. Chapter 2 deals with social calls in bats, their differences from echolocation calls, and the situations in which these calls are emitted in different contexts: Generic roost sites; Distress; Mother and offspring interaction; Co-ordination and group cohesion; Mating Behaviour (Subdivided in three sections: Resource defense polygyny, Female defense polygyny, Promiscuity); Food patch defense. Chapter 3 attempts to better structure the classification of the different types of social calls by proposing a nomenclature.The methodology for the collection and analysis of social calls is detailed in Chapter 4, while Chapter 5 lists the possible applications of the study of signals of social communication.

The bulk of the book (pp. 50–149) is devoted to case studies of the 23 species included, with a predominantly narrative description illustrated by numerous spectrograms. For each species, standardized headings are summarized in tabular form, making information clear and easily accessible. For some complex cases (such as the three pipistrelles: P. pipistrellus, P. pygmaeus, P. kuhlii) distinguishing criteria are broken down by categories in a summary table. Parameters measured from the signals (e.g., frequency, duration) are regrettably not quantified. Nevertheless, the original 178 .wave recordings can be downloaded from a link provided at the start of the book, allowing the reader to perform any measurements and listen to acoustic criteria in time expansion.

As the authors point out themselves in the preface, the subject is far from being exhaustively covered despite their important research. The acoustic social repertoire of bats is expected to be rich and complex due to at least three factors: the large number of species, the fact that the acoustic emissions are a centerpiece of their biology and ecology, and the highly social nature of their behavior between conspecifics. Therefore, our knowledge on this topic is at its infancy, both in terms of specific repertoires and their meanings. The announced purpose of this book is to present a current overview, richly illustrated by picture and sound, to motivate Chiropterologists for greater consideration of this component at the border between acoustics and ethology. And in this aim, they are successful; we highly recommend this book, it being both useful and enjoyable at the same time.

-- Michel Barataud * Acta Chiropterologica *

Whilst the echolocation calls of most bat species found in the UK have been pretty well described, relatively little is known about other vocalisations produced by bats and their functions. Social Calls of the Bats of Britain and Ireland is a new book which for the first time aims to bring together a collection of these calls and to summarise the existing knowledge about them. In the book, the authors provide some background on social calls and discuss how they may be classified and analysed. This introductory section is followed by a species by species description of a range of social calls that the authors have gathered from their own and others’ recordings. A nice feature is the addition of downloadable sound files which enhance the descriptions and sonograms of the majority of the calls. This new  book provides a great starting point for anyone setting out to study this topic.

* Bat Conservation Trust e-Bulletin *

Great new book Social Calls of the Bats of Britain and Ireland offers excellent descriptions, classifications, and recommendations for collecting social calls of bats. The book has detailed species information that visually explains social calls, but the best part is the downloadable audio tracks! Excellent resource for identifying bats.

-- Rob Mies * Organization for Bat Conservation *

Many sounds produced by bats when not commuting or foraging are often lower in frequency than the species’ echolocation calls. These are assumed to be for communication, and are often grouped together and referred to as ’social calls’ although the purpose of many of these are not known. Clearly understanding these calls has the potential to improve our ability to identify species for species where the echolocation is similar, and to assist in interpreting behaviour (e.g. territorial behaviour of males during the mating season).

This book is the first attempt to pull together and summarise the current knowledge of social calls of bats occurring within Britain and Ireland. This is a complex area of study, where there is still much to learn. However this book and downloadable call library does a really good job in highlighting the potential for social calls for understanding bats, and for making this information available to all. I know from my own work on bats in Norfolk, I have largely focused on echolocation calls, with another ground-breaking book published by Pelagic Publishing by Jon Russ on British Bat Calls: A Guide to Species Identification being my core reference. This new book on social calls is a perfect companion to this, and one which has already inspired me to look back at the recordings I have been getting this season. 

-- Stuart Newson * BTO Ne