Author Interview: The Handbook of Acoustic Bat Detection

Acoustic detection is a popular and widespread method of environmental assessment, and its use is increasing, driven by the development of increasingly accessible and sophisticated detection devices. The Handbook of Acoustic Bat Detection provides an in-depth understanding of the principles of acoustic detection, study planning, data handling, properties of bat calls, analysis of results, and the manual identification of species. It also includes information on quality assurance, the benefits and drawbacks of automatic species recognition, and the background physics of sound.

We are fortunate to have had the opportunity to ask the authors some questions.


The applications of data derived from acoustic bat detection are diverse and wide-ranging. What motivated you to write The Handbook of Acoustic Bat Detection and what impact do you hope the book has in this field?

In our daily work, we have seen a lot of improper use of acoustic data. Mainly driven by misconceptions regarding the interpretation of acoustic data and quite often due to missing basic knowledge on bioacoustics and signal analysis. With the easy availability of acoustic detectors and the relative simple usage, these problems became more common, especially in consulting activities. Many new “bat experts” appeared in the field basing their work on automatic detection and identification systems. We hope to help such users to gain a basic understanding of bioacoustics and give more experienced users new information to further improve their work. Thus overall we hope to improve the quality of projects based on acoustic data and increase the evidence level.

This book discusses some of the different methods for processing acoustic data, such as zero-crossing. What are the benefits of this method versus full-spectrum analysis?

The main benefit of zero-crossing is the much smaller amount of data produced and the possibility of listening to the recorded sounds directly. Full-spectrum detectors produce much larger amounts of data and do not allow direct listening to the bat calls. Yet, the benefits of zero-crossing are decreasing with cheaper data storage and higher processing power. Thus today one can nearly instantaneously listen to full-spectrum sound resampled to zero-crossing or heterodyne representation in real-time. In our opinion, the real-time data gives more insights into the calls on a much easier-to-understand level, yet we accept that experts can do powerful analysis with zero-crossing data as well.

You have all had many years of experience in this field; how has bat detection and acoustic analysis developed and changed since you first started?

We started working on bat acoustics in the field when only heterodyne or zero-crossing detectors were available. So in our early days, we walked through the field listening for bats. We were already interested in better and more reliable species ID back then. Then the time-expansion system was available as well as the Anabat system. We used time-expansion a lot, but both didn’t work well for our scientific research interests. So we developed with the batcorder a real-time detector that completely changed bat work in Germany within a few years. Back in the beginning, sound analysis of bat calls was something only a few were able to do. Now with fully automated systems, the whole process changed. Surveys can run for multiple months nearly everywhere – not only ground-based but also on wind turbines or off-shore. We collect billions of bat calls a year with these systems and thus are able to learn more about their calls and ecology. Yet this is not always the best, since a lack of bat knowledge often prevents optimal solutions for bat-related landscape changes.

Bat acoustic recording visualised through the Anabat Insight Software 

In chapter 11, ‘Quality assurance of reports’, you provide criteria to improve the quality of specialist reports used in impact assessments, such as which information should be included and the procedures that should be followed. How do you think the previous lack of clear guidelines has impacted bat surveying and, consequently, conservation?

In Germany, quite often surveys were conducted and it was later not possible to understand the low or high results since important information was missing. Also for legal complaints in planning processes, it was quite often impossible to understand how the data was actually sampled. If surveys and methods are well documented, it is much easier to evaluate the planning process and even more to work out optimal sampling schemes for following surveys in the new planning processes.

Now that this book is complete, do you have any future projects you would like to tell us about?

There are many projects – especially since we now face a major green-green dilemma with climate conservation often acting against biodiversity conservation. This especially is visible in the renewable energy sector. So currently some of us are investigating chances to further identify the possibilities of improving bat conservation for planning wind parks and other sources of renewables.

Another project is the ongoing improvement of species identification based on bat calls. We are working on new solutions to give better results.


The Handbook of Acoustic Bat Detection

Available for pre-order: Due September 2021

Paperback | £39.99

 

 

 

All prices correct at the time of this article’s publication.

July Top 10

NHBS’s Top 10 bestsellers July 2021

We love looking back at our bestsellers from the month before and are very excited to share our second Top 10 list, featuring the best of July.

This month, highlights include recent works such as Sphagnum Mosses and Seabirds, as well as some you may recognise from last month’s Top 10, Secrets of a Devon Wood and Insectinside, as recently featured on BBC’s SpringWatch.

 

seabirds: The New Identification Guide | Peter Harrison, et al.
Hardback | June 2021

In top place this month is Seabirds: The New Identification Guide, a 600-page treatment to all know seabird species. It’s the first comprehensive guide to the world’s seabirds to be published since Harrison’s Seabirds in 1983. This guide contains 239 brilliant, full-colour plates, along with detailed text covering status, conservation, geographic range and more.

Seabirds Publisher, Lynx Edicions, is also our publisher of the month for August!

 

a field guide to grasses, sedges, and rushes | Dominic price
Spiralbound | April 2016

Field Guide to the Grasses, Sedges and Rushes has moved up the list this month from the 7th spot and is a consistent bestseller for NHBS. This guide aims to simplify the identification of this fascinating group of plants, using characters that are both easy to spot in the field and simple to remember. Over 100 species are described, focusing on key features of both their genus and species.

Read our interview with Dominic Price here.

 

Sphagnum Mosses: FIeld Key to the Mosses of Britain and Ireland | Martin Godfrey and Karen Rogers
Paperback | July 2021

Brand new last month, Sphagnum Mosses: Field Key to the Mosses of Britain and Ireland is proving to be popular. This short handbook is intended to provide an accessible key for identifying Sphagnum species in the field.

It contains brief descriptions of the more important identification features, plus a guide to the vegetation types that the individual species occupy. As some individual specimens can be problematic, short keys based on microscopic characters are also provided.

 

Britain’s insects: A Field guide to the insects of Great Britain and Ireland | Paul brock
Flexibound | May 2021

Britain’s Insects remains just as popular this month! This field guide is an innovative, up-to-date, carefully designed and beautifully illustrated field guide to Britain and Ireland’s 25 insect orders, concentrating on popular groups and species that can be identified in the field.

 

Featuring superb photographs of live insects, Britain’s Insects covers the key aspects of identification and provides information on status, distribution, seasonality, habitat, food plants and behaviour.

 

 

Insectinside: Life in the Bushes of a Small Peckham Park | Penny Metal
Paperback | October 2017  

As recently featured on BBC’s Springwatch, Insectinside is a fantastic book featuring hundreds of species of insect that have all been found in Warwick Gardens in Peckham by author, Penny Metal.

We caught up with Penny to ask her some questions about her book – read the full interview here.

 

Field Guide to the Moths of Great Britain and Ireland | Paul Waring, Et al.
Paperback |  November 2018

The third edition of the Field Guide to the Moths of Great Britain and Ireland is a fully revised and updated version.

This field guide includes beautiful illustrations displaying key features to help with identification. It covers flight season, life cycle, larval foodplants, habitat and more, along with maps presenting distribution information.

The revised edition also contains an introduction explaining how the methods of identifying and recording moths have evolved over recent years.

 

Ecology and Natural history | David Wilkinson
Paperback | June 2021

The latest addition to the New Naturalist Series, Ecology and Natural History, makes it into the top ten again this month.

Ecology is the science of ecosystems, of habitats, of our world and its future. In the latest New Naturalist, ecologist David M. Wilkinson explains key ideas of this crucial branch of science, using Britain’s ecosystems to illustrate each point.

Read our Q&A with David M. Wilkinson here.

We have a limited number of signed bookplates for the hardback edition, available while stocks last. 

 

secrets of a devon wood: my nature journal | jo brown
Hardback | October 2020

Another repeat occurrence in this months Top 10, Secrets of a Devon Wood is still high up on NHBS’s list. Artist and illustrator Jo Brown started keeping her nature diary in a bid to document the small wonders of the wood behind her home in Devon. This book is an exact replica of her original black Moleskin journal, a rich illustrated memory of Jo’s discoveries in the order in which she found them.

Jo very kindly agreed to answer some of our questions for a Q&A. Read the full interview here.

 

A Comprehensive Guide to Insects of Britain & Ireland | Paul  D. Brock
Flexibound | October 2019

A Comprehensive Guide to Insects of Britain & Ireland is a complete, photographic field guide to over 2,300 species of insects in Britain and Ireland – including beetles, flies, ants, bees, and wasps. The clear photograph will assist in the identification of the majority of insects likely to be encountered.

This guide also contains concise text on behaviour, present-day conservation status, and pointers on species of similar appearance. Serious naturalists will welcome notes on areas to look for rarities and information on where to look for additional information on particular insect groups

 

All the Birds of the World | Josep Del Hoyo          Hardback | August 2020

Another title from our publisher of the month, Lynx Edicions, is All the Birds of the World. With the completion of the famed Handbook of the Birds of the World, this book lists all the birds of the world, allowing readers to browse and compare Earth’s amazing avian diversity between the covers of one volume.

 

 

Book Review: A Trillion Trees by Fred Pearce

A Trillion Trees is an optimistic take on the future of the world’s forests, with Fred Pearce believing that the damage humanity has inflicted can be undone, so long as nature is allowed space to recover. The book opens with an introduction to the myth and magic of forests. Through describing a botanical explorer’s conservation of orchids in the rainforests of Ecuador, recounting one of the author’s most memorable forest experiences (getting lost in a wood on the North Downs as a child), and presenting the varied reactions of early European explorers to the rainforests of the tropics, Pearce laments the loss of ‘primaeval wildness’ and the untouched forests of those times. 

Since 1992, Pearce has been writing for New Scientist magazine on the importance of trees, as well as their ownership, uses, protection, and destruction. He has spent his career contributing to multiple well-known publications, writing a range of books, and speaking on environmental issues such as carbon emissions, invasive species, and climate change. Despite forty years of continued reporting on global environmental issues, he maintains optimism for the future and for forest regrowth.

Pearce’s enthusiasm and respect for trees is clear throughout. This book celebrates trees, exploring their importance and the impact they have on the climate, the history of how our relationship with forests has changed, the recovery that is already taking place, and the future role of trees in an emerging community-centred approach to the land. Pearce intersperses topics on the politicisation of forest and climate research, the impacts of deforestation, and the damage of acid rain. He also includes some of his personal adventures, such as his visit to the ATTO, a 325m tall tower in the middle of the Amazon Rainforest, and the exploits of others, such as a bush pilot’s flight along the ‘flying river’ above the Amazon. 

A Trillion Trees champions the role of trees in more than just the fight against climate change, but also in the daily lives of everyday people. The tales of forest regeneration tell of the economic value of trees, through tourism, increased resources, and even ‘inspiration for artists’. Pearce presents the debate of rewilding versus replanting forests, asking who should be responsible for the regeneration of our forests and whether we should be taking an active role at all.  The ‘great forest restoration’, as Pearce puts it, is occurring less due to the many government plans and promises of replanting, and more through the process of rewilding. Where farmers and landowners have stepped back, Pearce notes that nature seems to move in, allowing much of the fields and pastures to revert to shrubland and then to woodland. The return of wildlife soon follows. 

In a world scrambling for solutions to combat climate change, the notion of stepping back and taking a passive role in regeneration may be a daunting one. However, it is not the only solution Pearce suggests. In the final section, Forest Commons, the author advocates for the rights of indigenous people to own and manage the land and forests within their traditional/ancestral territories. The rate of deforestation is far less in areas owned and managed by indigenous people than in other areas, even nature reserves, with communities seeming more resilient against threats such as illegal logging than government-owned parks. 

This book closes by paying homage to the wild spaces near the author’s home in London, their ability to filter out noise and pollution, and the calming, cooling effects trees can have in otherwise overheated cities. After a book full of adventure and debate, the postscript acts almost like the ‘forest bathing’ it discusses, ending the book in a calmer tone that calls for more woods full of darkness and gnarled, twisted yew trees and forests that harken back to the lost primaeval wilderness.