An accessible and comprehensive guide to all things acoustic bat detection. This highly illustrated handbook provides an in-depth understanding of acoustic detection principles, study planning, data handling, properties of bat calls, manual identification of species, automatic species recognition, analysis of results, quality assurance and the background physics of sound. No other method of detecting bats is so popular and widespread in the context of environmental assessment and voluntary work as acoustic detection, and its increased use has driven the development of a large number of sophisticated devices and analytical methods. Acoustic detection has become a standard approach for establishing the presence of bats, carrying out species identification and monitoring levels of activity. The resolution, accuracy and scale with which these tasks can be done has risen dramatically with the availability of automated real-time recording. But anyone interested in acoustic recording will quickly recognise that there are still quite a few open questions about the limits and possibilities of acoustic detection. Clear definitions of how to handle the data are usually missing, for example, and there are no clearly described activity indices. In response to the lack of thorough information on the underlying science of acoustic detection, the authors present this handbook.

Bat detector surveys are carried out by ecological consultants, researchers, conservationists and hobbyists. Understanding and categorising non-bat sounds in surveys offers the potential of knock-on benefits for informing development projects (e.g. other important records discovered within a site), as well as the possibility of associated conservation benefits. In recent years the number of people carrying out these surveys and recording calls with bat detectors has grown considerably. These surveys often generate vast amounts of audio recordings, resulting in the heavy workload associated with completing the sound analysis and reporting process. Those carrying out analysis can be distracted, intrigued or delayed owing to the occurrence of recordings that are unfamiliar and not identifiable to them. These recordings can relate to ‘difficult to ID’ bat species, but also, often, sounds not related to bats. This can be especially true when noise triggers such as insects, small mammals or birds look like bat-related noise. Therefore, only knowing what bats sound like is not enough. It is extremely useful to know what other sources of noise look and sound like within the same soundscape. This resource will help bat workers, in whatever environment they are in, to be more confident in recognising, categorising and dismissing other sounds. The book includes a substantial downloadable sound library (.wav format) that readers can listen to by ear or process through sound analysis software. Is That a Bat? also caters for sounds that are also heard by ear alone, in the field, during the hours of darkness. These scenarios often have bat surveyors intrigued or confused as to what they are listening to. Occasionally, knowing what these sounds are could be important, or at the very least, of interest. The first chapter caters for the subject overall, including suggestions from the author as to why the subject matter is of value. It also discusses bat-related calls (including social calls) with a view to offering comparisons against the other sources of sound discussed in separate chapters. Continuing through the book, there are chapters covering the following: small mammals; amphibians; insects; birds; electrical/mechanical noise; and other noise/nuisances. Within each chapter there are sub-sections about bat detector recorded sound, sound by ear, as well as advice on techniques and methods to reduce or increase the likelihood of recording other sounds. The book concludes with associated appendices, including a ‘Problem Solving Key’ to help those encountering an unfamiliar sound to narrow it down to the likely source. With technology advancing at pace, the technical ability of the analyst is of huge importance. With a wider perspective and more knowledge, those responsible for interpreting field encounters can be more confident when making decisions about sources of sound. Apart from that, ‘knowing stuff’ makes the job far more interesting and gives the bat worker a greater appreciation of the natural world within which they are working.

A comprehensive guide to the calls of the 44 species of bat currently known to occur in Europe. Following on from the popular British Bat Calls by Jon Russ, this new book draws on the expertise of more than forty specialist authors to substantially update all sections, further expanding the volume to include sound analysis and species identification of all European bats. Aimed at volunteers and professional alike, topics include the basics of sound, echolocation in bats, an introduction to acoustic communication, equipment used and call analysis. For each species, detailed information is given on distribution, emergence, flight and foraging behaviour, habitat, echolocation calls – including parameters of common measurements – and social calls. Calls are described for both heterodyne and time expansion/full spectrum systems. A simple but complete echolocation guide to all species is provided for beginners, allowing them to analyse call sequences and arrive at the most likely species or group. The book also includes access to a downloadable library of over 450 calls presented as sonograms in the species sections.

This guide provides descriptions of when the bat species resident in Britain and Ireland use natural and human-made rock habitats, how they use them, and the environments each species occupies therein. For the first time it brings together findings from historical scientific investigations, useful photographic accounts and open-access biological records, along with a rich seam of new data – all in a practical and user-friendly structure. The book encompasses: ~ Descriptions of the features that a climber, caver or professional ecologist might encounter on and in rock habitats where bats roost. ~ Recording criteria for both the physical and environmental attributes of different features and situations. ~ Identification of suitability thresholds against which the recorded information can be compared to assess the likelihood that a specific feature might be exploited by a particular bat species. ~ Suggestions for how to avoid mistakes and difficulties when performing a survey. The intention is that using this book will help generate standardised biological records which can feed into the fully accessible online database at www.batrockhabitatkey.co.uk. These data will be analysed to search for patterns that can increase the confidence in the suitability thresholds and help build roost features that deliver the environment each species really needs. As well as offering many new insights, this book allows the reader to participate in cutting-edge research.

This is a guide to finding tree-roosts. It is the result of the collaborative efforts of professional surveyors and amateur naturalists across Europe as part of the Bat Tree Habitat Key project, and represents a combination of firsts: It is the first time legislation and planning policy have been reviewed and put to practical use to define an analysis framework with clearly identifiable thresholds for action. Yet, despite its efficacy in a professional context, it is also the first time a guide has been produced that is equally effective in achieving its objective for amateurs. It is the first time such a method has been evidence-supported throughout, with summary reviews of each aspect of the roosting ecology of the individual 14 tree-roosting species, with illustrative photographs and data to which the reader has open access. It is the first time a repeatable analysis framework has been defined against which the surveyor may compare their results at every stage, from the desk-study, through ground-truthing, survey and analysis, thereby ensuring nothing is overlooked and that every result can be objectively compared. The survey and analysis framework itself is ground-breaking in that it may readily be adapted for any taxa; from moths, through amphibians, reptiles, birds and all other mammals. Used diligently, these methods will reward disproportionately and imbue the reader with renewed confidence as they quickly progress from beginner to competency. Thus, this book is for everyone who has ever wanted to find a tree-roost, or to safeguard against inadvertently damaging one.

Arguably biosonar is one of the ‘eye-opening’ discoveries about animal behavior and the auditory systems of echolocators are front and center in this story. Echolocation by bats has proven to be a virtual gold mine for colleagues studying neurobiology, while providing many rich examples of its impact on other areas of bats’ lives. In this volume we briefly review the history of the topic (reminding readers of the 1995 Hearing by Bats). We use a chapter on new findings in the phylogeny of bats to put the information that follows in an evolutionary context. This includes an examination of the possible roles of Prestin and FoxP2 genes and various anatomical features affecting bat vocalizations. We introduce recent work on the role of noseleafs, ears, and other facial components on the focusing of sound and collection of echoes. ​

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.