Tag: Mammals

Neil Middleton on the 4th edition of Bat Surveys for Professional Ecologists

The 4th edition of Bat Surveys for Professional Ecologists: Good Practice Guidelines is the latest update of the Bat Conservation Trust (BCT) Guidelines and features new content on biosecurity, night-vision aids, tree surveys and auto-identification for bat sound analysis. Several key chapters have been expanded, and new tools, techniques and recommendations included. It is a key resource for professional ecologists carrying out surveys for development and planning.

Neil Middleton is a licensed bat worker and trainer. He is the Managing Director of BatAbility which offers bat-related and business skills development courses and training throughout the UK and Europe. He kindly agreed to take the time to write an article for us which will help ecologists and bat workers assess some of the key content and changes within the 4th edition of the Bat Survey Guidelines, and evaluate how this is likely to impact you, your colleagues and your business.

I have been asked to write this blog for NHBS regarding the recently published 4th edition of the BCT Bat Surveys for Professional Ecologists: Good Practice Guidelines. Straight away I feel I should say that, broadly speaking, we (BatAbility) are supportive of the overall spirit of intent that these new guidelines are seeking to achieve.

The contributors to the finished work and the editor of the final draft will have, I’m sure, had much debate about the final wording of the guidelines. It certainly cannot have been an easy task to come up with approaches that a broad range of experienced people, each with different backgrounds, were able to fully agree upon (or at least not disagree). In addition to which, these guidelines need to cater for all the component parts of the UK, where differences in legislation, planning, licensing etc. apply.

What follows are my thoughts on why you need to be up to speed with what’s happening. When I discuss some of the points you need to be aware of, it’s not that I am criticising or disagreeing with what has been produced, it is more that I am encouraging you to think about things that may not immediately be apparent when it comes to impacting (positively or negatively) upon your daily business operations.

Broadly speaking, these Good Practice Guidelines are what we all need to be referring to now for guidance and, barring any new properly released formal material direct from BCT (i.e. it doesn’t matter what someone says on a social media post or during a webinar) that either updates, changes or gives additional explanation to what is in the 4th edition, this is where we, as a community, are at. BCT have confirmed that a few changes to the text will be made by way of an amendment document and this, in conjunction with printed Q&A material resulting from BCT webinars (November 2023 and February 2024), will prove to be essential complimentary reading for everyone relying upon these guidelines during their day-to-day work.

At this stage, I feel that it is also important to say, and BCT have been very keen to emphasise this point (e.g. during their webinars on the subject), that the guidance is very clear about deviating from its approaches where specific cases and/or experienced, professional judgement suggests that a different approach can be taken for good reason, provided that it is fully disclosed and discussed within generated outputs (e.g. reports going to local planning departments). The material produced is described as ‘guidelines’ after all, and should not be used prescriptively when common sense, good scientific rationale or proportionality, as examples, suggests otherwise.

These updated guidelines were keenly awaited by bat workers for some time leading up to their publication.The driving force behind the update was thought mainly to be the integration of Night Vision Aids (NVAs) into our bat survey approach, as initially described within an Interim Guidance Note published in May 2022 and covered in this article on the BCT website.

I mention this for two reasons. Firstly, it’s what I feel almost everyone was genuinely expecting. Secondly, these revised guidelines don’t (as anticipated rightly or wrongly!) fully address some of the specific aspects of where the NVA debate is going to finally arrive. Regarding this aspect of bat work, the finer detail around this matter is now being tackled by a review panel, and BCT will inform us as/when they are in a position to do so. In the meantime, the Interim Guidance (2022) remains as an additional, essential point of referral. Having said that, within these new guidelines there are regular pointers, reminders and requirements that NVAs should be incorporated within survey design.

So, why do we need to pay any attention to these new guidelines? If they are not telling us about the specifics of the NVA approach, then you may very well think that there’s not much value in getting your own copy and reading through, yet again, what was there before. Yes, you may very well think that. Yes, you would be very wrong.

There is so much in here that is going to make your life as a bat consultant different to how it was up until last year (2023). There are undoubtedly elephants potentially in some people’s rooms. But an hour after sunset when it’s too dark to see, some people may not be aware that elephants lurk (well not unless they have an NVA, and it’s pointing in the right direction). There are resourcing implications, cost implications, tendering implications, health and safety implications – there are all of these and more that you need to be aware of. And by implications I mean a mix of positives and negatives. It is a classic situation whereby in solving a range of issues and making clarifications on others, new issues and opportunities inevitably arise.

From a surveyor’s point of view, the dreaded dawn work is mostly redundant, although I feel there are still going to be occasions from a bat behaviour point of view, and from a health and safety point of view (e.g. working within busy town centre areas) where dawns could still occasionally be a better, or even a desirable approach. The guidelines certainly don’t say you should never do a dawn survey again, full stop.

From a business owner’s perspective there are matters that will need serious consideration and budgeting for. This could impact (again negatively or positively) upon your turnover, your approach to tendering, resourcing, the deployment of staff and equipment, as well as the careful balancing of your team’s time at their desks versus time in the field. All of this, of course, needs to be considered against the benefits to bat conservation. The challenge on the business model is not necessarily a bad thing, provided you are fore-armed and have seriously thought through how these changes impact upon your organisation.

Please don’t construe that I am not supportive of what these guidelines are seeking to achieve. In many respects, from a conservation perspective, I feel things have moved closer to where they should be. Balanced against this, however, I urge you to be aware that you need to get your head around the new approaches as a matter of urgency, and build into your day-to-day workings methods of adapting to the changes.

There is neither the time nor the space to cover it all here, and to do so would merely be to repeat what was contained in the guidelines in any case. What I am seeking to do is alert you to the fact that, despite how much you may have seen on social media etc. relating to the NVA debate, there are arguably equally as BIG matters contained within the new edition that don’t relate to the use of NVAs.

Here are some key points of where things have really changed, in my view:

  • Dawn surveys are pretty much redundant, as we are now pressed to doing dusk surveys with NVAs. This is great from a work-life balance, but it also removes up to 50% of the previously available time slots on your survey calendar.
  • NVAs are to be deployed on pretty much every emergence survey, covering the survey subject as fully as possible, with the associated implications for reviewing all that footage and storage of data. Video footage is much larger than the pure audio that you will have been accustomed to.
  • A licenced bat worker is required to be present for any field work where a licensable situation could occur, no matter how likely or unlikely, be that structures or trees. Following the definite statements in the 4th edition, there is no longer any ‘wiggle room’ on this issue.
  • Bats and Trees – aerial assessment (be that by ladder, rope or MEWP) is pretty much the desired approach, meaning that this will be a greater part of these jobs and, in conjunction with this, licensed bat worker(s) will need to be present.
  • Due to the increased requirement for licensed bat workers to be present far more often than previously was the case, and the increase in tree climbing work where licensed bat worker(s) should also be used, there are resourcing implications that need to be considered when it comes to training in these areas. It is important to be aware that not every licensed bat worker within a business is either capable of or desires to climb trees. Also, in some business models, the licensed person/people are in more senior positions where their presence in the field conflicts directly with the role they are being asked to perform for the business (e.g. team management, client meetings, tendering, business process improvement). So, for some businesses, depending upon their current resources of licensed bat workers, there may need to be a rethink.

What I have described above is most definitely not the full suite of changes, but hopefully it’s enough to demonstrate that you need to get on top of what’s in there.

The key message is, if you haven’t already got yourself a copy and read it through in detail, then as a matter of urgency you should do so. Then you will be able to consider how you are going to achieve what is required.

The 4th edition of Bat Surveys for Professional Ecologists is available as a downloadable non-printable version direct from the BCT website.

Also available as hard copy from nhbs.com – remember to use your BCT membership number to get a 20% discount.

Author Q&A with Chantal Lyons: Groundbreakers

Groundbreakers jacket showing a wild boar drawing on top of a green background.Big, messy and mysterious – crossing paths with a Wild Boar can conjure fear and joy in equal measure. In Groundbreakers, Chantal Lyons gets up close and personal with this complex and intelligent species in the Forest of Dean, and investigates the people across Britain and beyond who celebrate the presence of these animals – or want them gone. From Toulouse and Barcelona where they are growing in number and boldness, to the woods of Kent and Sussex where they are fading away, to Inverness-shire where rewilders welcome them, join Chantal on a journey of discovery as she reveals what it might take for us to coexist with the magnificent Wild Boar. 

Chantal Lyons, author or Groundbreakers, stood against a tree.Chantal Lyons is a naturalist, writer and science communicator. Having grown up in the tidy countryside of Kent, her encounters with the growing rewilding movement opened her eyes to the potential for restoring nature in Britain, and inspired her to study the relations between people and Wild Boar in the Forest of Dean. She currently lives in Cheltenham, never too far from the boar. 

Chantal recently took time out of her busy schedule to tell us about her first experience with a Wild Boar, her hopes and fears for the future of their populations in Britain, and more.

First of all, could you tell us a little bit about yourself and what led you to writing a book about Wild Boar in Britain? 

Up until my mid-twenties I spent all my writing time churning out unpublishable fantasy and sci-fi novels, alongside a zig-zagging career in the charity sector. The journey to Groundbreakers was perhaps a ponderous one – it started when I went to the Forest of Dean in summer 2014 to research a Masters dissertation in environmental social science. The Forest of Dean was, and still is, one of the few places in the country where Wild Boar have returned since their extirpation from Britain around 700 years ago. I wanted to find out from local residents what it was like to suddenly find yourself living alongside a big, wild, and utterly unfamiliar creature. What I discovered from those interviews astounded me, and I was sure that some established nature writer would soon publish a book about the return of boar to Britain and what this meant for us. No one did. After seven years, I decided to send off a proposal to a publisher who I’d encountered on Twitter, and it snowballed from there. 

Could you tell us about your first real life experience with a Wild Boar? 

It was a long time in coming! While I was in the Forest of Dean doing the Masters research, I used every spare moment to explore the woods on my own, often following locals’ leads. It always came to nothing. The boar seem to be like cats – you seem to be more likely to meet them the less you want to. But eventually, at the tail end of summer, I went to a spot where I’d heard from someone that a sounder (a family group of boar, which is always led by a matriarch) had been foraging each evening. I heard them softly calling to each other, then there was a rustling in the bracken, and an adult stepped out onto the path to get a look at me. We stared at each other for about two seconds, she gave a belching alarm call, and then she vanished with her family.  

Wild boar and 7 piglets lead down on a rocky bank in the Yorkshire Dales.
Wild boar at Bolton Castle in Yorkshire Dales National Park, by HarshLight via flickr.

I appreciated the ways in which you speak about rewilding, in particular the importance of nuance and accepting the unknown. Do you think that uncertainties about the best way to undergo reintroduction projects and their expected outcomes are a significant hindrance to their implementation? 

I have heard many a time from rewilding practitioners that the inherent uncertainties in rewilding can make it especially challenging to gain funding, given that projects aimed at restoring nature have traditionally been expected to be able to set clear targets and end-goals. But beyond practicalities like money, I think the bigger challenge is the attitude that reintroducing species for rewilding purposes is too big an unknown, and therefore too big a risk. Of course we should aim to conduct as much scientific research and gather as much knowledge as possible, but we are running out of time to reverse the haemorrhaging of our biodiversity in Britain and globally. To me, it beggars belief that we seem quite happy to continue doing all kinds of things that we know are massively damaging the environment, but reintroducing species? Why, that’s a step too far! 

Close up image of two wild boar walking through mud with their snouts and feet covered in wet mud.
Wild boar, by Marieke IJsendoorn-Kuijpers, via flickr.

One part of the book that particularly resonated with me was in ‘The Risks of Being Alive’ where you speak about how, for most modern humans, ‘nothing matters more in life than eliminating all risk to it – even at the cost of happiness’. What do you think it would take for humans to accept more wildness into their lives? 

Maybe it’s a cliché to say this, but I think it hugely helps to engage children with nature from a young age, and to continue doing so as they grow up. That of course means ensuring that everyone can access nature. 

Beyond that, the question of how to convince people to accept more wildness is an incredibly tricky one, especially in a place like Britain which suffers so badly from ‘ecological tidiness disorder’ (as Benedict Macdonald puts it in Rebirding). The problem is that most of us have not made the connection between our tidy sterilised surroundings and the loss of nature. There is a lack of understanding that the majestically bare plains of Dartmoor or our rolling green fields mean an absence of life; and that you need all manner of species, including big ones, to ensure healthy ecosystems. I didn’t realise this for years. But once you know, you can’t stop wanting to bang the drum. 

What are your biggest hopes and worst fears for the future of Wild Boar populations in Britain? 

I want the planned, country-wide reintroduction of Wild Boar to become accepted both politically and societally. In the meantime, I hope that the few boar we do have are allowed to thrive. That means more oversight of people carrying out legal shooting of them on their land, and – in the case of the Forest of Dean population – better censusing methods to ensure they are not over-culled (though some culling will always be needed, as the boar currently lack other predators). 

What am I most afraid of? That very soon, a disease called African Swine Fever (ASF) which burns through pig populations like wildfire will make its way into Britain. Since Brexit, border controls on pork imports have been so lax that experts think it’s only a matter of time before ASF reaches us. Forestry England is primed to wipe out every last boar in the Forest of Dean if the disease is ever detected in the population. And once they’re gone, it seems very unlikely that they would ever be reintroduced (legally or illegally) again. We will miss a miraculous chance to kickstart the landscape-scale restoration of nature in Britain.  

Wild Boar piglets running across the road in a national park park with the sun out.
Wild Boar Sus Scrofa, by Björn, via flickr.

Finally, what is occupying your time at the moment? Are there plans for further books in the pipeline? 

I work full-time as a science communicator, which does narrow my research and writing windows! But I am currently working on a proposal for book number two. It’s intended to be something of an evolution of Groundbreakers, picking up a thread that often emerged during my research interviews with people, but which I couldn’t possibly have fitted into this first book…  

Groundbreakers book jacket showing a wild boar drawing on a faded green background with yellow test and a signed copy bubble in blue.Groundbreakers is available from our online bookstore.

 

Author Q&A with Derek Gow: Hunt for the Shadow Wolf

Renowned rewilder Derek Gow has a dream: that one day we will see the return of the wolf to Britain. As Derek worked to reintroduce the beaver, he began to hear stories of the wolf. With increasing curiosity, Derek started to piece together fragments of information, stories and artefacts to reveal a shadowy creature that first walked proud through these lands and then was hunted to extinction as coexistence turned to fear, hatred and domination.

With bitingly funny but also tender stories, Hunt for the Shadow Wolf is Derek’s quest to uncover the true nature of this creature because, as we seek to heal our landscape, we must reconcile our relationship with it. Before we can even begin to bring the wolf back, we need to understand it.

Derek recently took time out of his busy schedule to talk to us about Hunt for the Shadow Wolf, including how his fascination with the wolf began, what role it could play in Britain’s landscape and more.

As well as being packed with personal stories and fascinating snippets of wolf biology and behaviour, Hunt for the Shadow Wolf is an incredibly well-researched history of the wolf, told through the myths and legends that abound throughout our lands. How and when did your fascination with the wolf and its history in Britain begin? 

Hunt for the Shadow Wolf Chapter 3 sketch. if a wolf baring its teeth in a graveyard.

My personal interest in the wolf story began early. I remember quite clearly my grandmother, who was a slight, erect, sprightly soul, telling both myself and my bored brother on a long car journey to Dundee the story about a place called wolf clyde which was near to where we lived in the Scottish borders at that time where the last wolf in Scotland was killed. It was just nonsense about a woman with children being attacked by the wolf which she brained in response with a pancake griddle, but nevertheless it began a slow smoking interest in the old myths which given the opportunity I was keen to explore further.  

Why do you think that an understanding of the historical culture, myths and legends surrounding a species has relevance to its conservation and role in our ecosystems today? 

A factual understanding of the history of this much maligned species in Britain is very important as the lies we made up in the darkness of our ignorance to try to twist the cultural character of the wolf into one of loathing and repulsion still sway the responses of a phenomenal number of individuals and organisations to this day. Despite the very best of our advanced understandings of what wolves are and what they do, this toxic taint is still bubbling strongly.  

Hunt for the Shadow Wolf Chapter 6 sketch of a wolf baring its teeth at a woman who has a sword in her hand and is trying to protect her sheep from an attack.Even in children’s tales, the wolf invariably represents a character of fear, violence and threat. Do you think these types of stories have a significant role to play in the development of our feelings towards wolves as adults? 

Absolutely as they reflect only the darkness in the minds of the adults who wrote them and by so doing chose to corrupt a bad reputation without thinking into an even darker evil to infect the minds of the young. Nowadays it’s gratifying to see in so many good environmental centres throughout Europe, within the wolves expanding range, more understanding and compassionate explanations about both their history and the reality of living with them.

Britain is in a unique position compared to mainland Europe in that wolves will never be able to repopulate of their own accord. Do you think that a reintroduction project will ever occur, and what are the key challenges that stand in its way? 

I think we should reintroduce the wolf and prepare the way for even more of our lost beasts. Farming has had it all its own way without balance of any sort. If a species gets in our way, we kill it. It’s what we are doing to badgers right now. In the past we inflicted so much heartbreakingly visible cruelty. Now, we destroy on a scale that’s colossal without thinking about the smallest of creatures and those tinier still that inhabit the soil. It’s a viciously unnecessary process.

Eurasischer Wolf sniffing a moss covered rock, taken by C Bruck.
Eurasischer Wolf (Canis Lupus) by C. Brück

What role do you think the wolf could have in healing the landscapes of our currently denuded Britain? 

I think they would both move deer considerably and by doing so disrupt their grazing patterns for the betterment of forest understory regeneration. I think they would make those that keep sheep consider their worth and then, if these animals are of value, protect them better. I think their very presence, wild but unthreatening, would more than that of any other creature enable all of us now living on this island to establish, if we wished to do so, our relationship with the natural world.  

As well as travelling widely to locations where wolves live in the wild, you have also had the incredible experience of hand-rearing wolves in a wildlife centre. What is your most memorable first-hand experience with a wolf or wolf pack? 

Naida, one of my tame cubs, ate my car keys. I only had one set and had to wait for what seemed an eternity for them to pass through her before picking my way through her enormous turds to get them back.

Title page for Hunt for the Shadow Wolf showing a map of Great Britain with different wolf locations labelled across the country.Finally, what is occupying your time this winter? Do you have plans for more books? 

Lots of things. The last of bits of farming – feeding my cows. Dog walks and avoiding the rain. Trying to develop a foundation to help us breed even more threatened British species for reintroductions. And books? Well, on long dark evenings I have been researching the intriguing history of the European Bison. not the bits of sadness that brought the species to its knees in the early 20th century, but the complicated individuals who for a time held its future in the palms of their hands. Great characters like the 11th Duke of Bedford, who assembled breeding herds of threatened species on his Woburn estate, and tyrants like Hermann Goering, who used slave labour to create vast parks within which he hunted. It’s an intriguing slant that’s little known but it saved the species for a time when the world for them has become a better place where they can roam in peace, a range that is vast. There might be a book in that!! 

Explore other titles by Derek Gow here.

Author interview with Neil Middleton and Stuart Newson: Sound Identification of Terrestrial Mammals of Britain and Ireland

This groundbreaking book provides the reader with a unique and practical guide to collecting and using acoustic survey data to identify terrestrial mammals. Covering 42 species that can be found in Britain and Ireland, the text includes guidance on survey methods, analysis of sound recordings and details of appropriate software. As well as containing specific spectrogram examples for each species, the book allows the reader access to a downloadable sound library containing more than 250 recordings.

Neil Middleton is a licensed bat worker and trainer and is the owner of BatAbility Courses & Tuition, an organisation that delivers ecology-related skills development to customers throughout the UK and beyond. He has studied bats for over 25 years, with a particular focus on their acoustic behaviour (echolocation and social calls) and is the author of Social Calls of the Bats of Britain and Ireland, Is That a Bat?, and The Effective Ecologist.

Stuart Newson is a Senior Research Ecologist at the British Trust for Ornithology (BTO), where he is involved in survey design and data analysis from national citizen-science surveys. Stuart’s work on bioacoustics has included creating tools to identify European bats, bush-crickets and small mammal species from their ‘calls’. This resulted in the BTO Acoustic Pipeline, which integrates online tools for coordinating fieldworkers, processing recordings, and returning feedback.

Neil and Stuart recently took some time out of their busy schedules to answer some of our questions about their most recent book. In this Q&A we discuss the challenges involved in acoustic monitoring of mammals, the author’s hopes for the future of this area of study, and much more.

You each have a passion for acoustic monitoring – how did you come to be working together on this project?

Before we first met, Stuart was becoming interested in what else is recorded as ‘by-catch’ when you leave out a static bat detector to record bats. He had previously become interested in the sound identification of bush-crickets which are commonly recorded during bat surveys in southern Britain, and thanks to work that Neil was involved with (e.g. the first edition of the book The Social Calls of the Bats of Britain & Ireland), Stuart was becoming increasingly interested in bat social calls. At this time, he realised that small mammals are also quite commonly recorded as ‘by-catch’ during bat surveys, and was starting to appreciate that unless you had a good understanding of bat echolocation and social calls, there was scope for mis-identifying small mammals calls as being produced by bats.

When Neil started working on the book, Is That a Bat? A Guide to Non-Bat Sounds Encountered During Bat Surveys (ITAB), Stuart had already made available some online resources to help bat workers identify bush-crickets, which were able to feed into Neil’s book, and he also had some first recordings of some small mammal recordings that he was able to contribute to ITAB, which were very useful additions to the recordings that Neil had been gathering independently.

At about the same time, Stuart had met Huma Pearce, the third author on this book, and had started to work with her on an ‘edge-of-desk’ project to try and collect sound recordings for every species of small mammal in the UK. The aim was to try and collect many hundreds (ideally thousands) of sound recordings of every small mammal species in Britain and Ireland, which we wanted to build into bat classifiers to be able to assist with automatically identifying small mammals (as well as bush-crickets), when these are recorded as by-catch during bat surveys.

Working with Huma, and then Neil, to collect recordings for small mammals to feed into ITAB, and for Stuart to feed into his classifiers, we were now collecting a lot of recordings of small mammal species. After the publication of ITAB, we had learnt a lot more between us, so we wrote a more detailed guide to the sound identification of small mammals in Britain and Ireland, which was published in British Wildlife. After being approached by Pelagic Publishing, Neil was asked if he could author a book covering all terrestrial mammals in our part of the world. This was a much wider group than the one we had worked on up until that point. Neil agreed to the book idea, but only on the basis that Stuart and Huma would be involved as well. Thankfully both Stuart and Huma were ‘up for it’ and between us we managed to produce the book. I think we would all agree that if any one of us had not been involved, the job would’ve been considerably harder and taken much longer.

There currently exists a huge sound library of vocalisations of bats and cetaceans and their use in monitoring these species is now mainstream. Why do you think that this approach has not, so far, been used for other mammals such as those covered in your book?

We think that the main reason that so little has been done on the sound identification of terrestrial mammals (other than bats), is that for small mammals the call rate is quite low compared with other groups such as bats, and because the vocalisations can look like bat calls. I think until our various pieces of work, they have been largely overlooked. Until relatively recently, bat social calls had also been largely ignored by many bat workers, so there were few possibilities for noticing or identifying small mammal calls via that group. For audible mammal species, such as deer, there are alternative survey methods, such as visual surveys, and combined with this the call rate is again quite low, so without tools to help find these calls within large acoustic datasets it has been challenging to find and identify vocalisations by these species. In addition, before this book there was no resource or reference that people could use to help support the sound identification of audible mammals across the full range of species.

Added to this, we feel that the subject is difficult for many people in the non-bat mammal world to engage with and/or know where to start. Hopefully this book will open people’s eyes (and ears!) to the subject, thus meaning that more people will pay more attention to acoustic identification of these species, which will also mean that, overall, our rate of learning as a community will increase substantially as we begin to find out even more about the subject, including of course things that we didn’t appreciate at time of writing.

As well as providing the information and data required for species identification, do you think that acoustic data have the potential to tell us more about species behaviour, social interactions and population dynamics?

We think that there is huge potential for acoustic data to tell us much more about species behaviour, social interactions and population dynamics. As explored in the book, for some species we are able to relate particular call types to behaviour or status, but we still have a lot to learn for many of the species that are included in the book, in order to be able to understand in what situations particular calls are produced. By writing this book, we hope that this will inspire others to build on our work, and to accelerate an improvement in knowledge.

Which of the British terrestrial mammal species have you found the most challenging to study and why?

It is difficult to give a single answer to this one, but despite each of us having separate thoughts we would all agree on the following.

It was extremely difficult to collect or find existing sound recordings of rabbits and hares, because the call rate is extremely low. Huma (assisted by others) put lots of effort into rabbits, but sadly the results were zero. Separately Stuart tried to collect recordings of moles, by sinking microphones into the ground along mole tunnels, but he had no luck despite several weeks of effort.

Stuart would like to do more work on the sound identification of mustelids, which we feel we do not understand as much as we would like. We would all like to continue with more work on the small mammals, although we would each have different priorities in that respect. Shrews are of particular interest to us all, and Stuart in particular would definitely like to try and collect more sound recordings of Water Shrews.

Researchers have previously observed regional differences in the vocalisations of small birds recorded in various locations around Britain. Did you notice any geographic variations in the sounds produced by the mammal species you studied?

Personally, we haven’t seen much, if any, evidence of geographic variation in the recordings that we have looked at, but there could very well be regional differences. For some species it can be shown that differences occur at the individual level. This being the case, you could perhaps expect to see differences between social groups and, as such, regional and national differences too. At this point in time the amount of data we have is too small and hasn’t been collected with this in mind, and therefore we haven’t gone looking for an answer to this question ourselves.

There are currently several citizen science projects around the UK that the public can submit sightings to (such as those organised by the Mammal Society or apps such as iRecord). Is there currently anywhere that people can submit records resulting from acoustic data? Or somewhere they can submit their recordings in the hopes of building a library of sound files for each species as there is for bats?

Not that we are aware of, in the style that you have suggested by your question. However, if someone has heard (not seen) a species and they are happy that it is a diagnostic record for that species in a particular area, we would see no reason why a citizen science project would not accept the ‘sound’ as a valid record of the species being present at that location at that point in time. The key to this, however, is being confident that what was heard couldn’t be a similar noise made by something completely different – so we urge caution. It should also be remembered that in some cases sound identification may actually be more reliable than a visual record of a distant mammal, or a small mammal irrespective of how close it may be to the observer.

In a slightly different direction to your question, Stuart is best placed to talk about the use of such calls in building classifiers. His main interest in mammals has been to build a large sound library of known species recordings that can be used to build classifiers that can help identify the calls of different species automatically within recordings, with the book being secondary or a by-product of this. He believes that having such tools is essential for helping to find the calls of terrestrial mammals in large acoustic datasets, particularly for species where the call rate is low. The sound identification of all species of small mammals included in the book has been built into the ‘bat’ classifiers that comprise the BTO Acoustic Pipeline. The Acoustic Pipeline also includes specific classifiers for some audible species, including the Edible Dormouse. To the best of Stuart’s knowledge this is the first attempt from anywhere in the world to build classifiers for the sound identification of a complete assemblage of small mammals.

What are the next steps required to progress this research and what are your hopes for the future of this field of study?

There is still a lot to learn about the sound identification of mammals in Britain and Ireland, but there are some species groups on which we know we have done much less work and have less understanding than others. In particular, we think that acoustics could be useful for detecting the presence of mustelids (as we have already demonstrated for mice, rats, voles, shrews and dormice), but we would need to try and collect many hundreds (ideally thousands) of known species recordings, to be able to understand the full range of calls that a species can produce. This information could then also be used to create automated classifiers, thus enabling the possibility of efficient detection of species in this group from within large datasets.

As a longer-term ambition, Stuart is keen to work further on the wider sound identification of European mammals, and to extend the geographic and taxonomic scope of the BTO Acoustic Pipeline. Currently, he is able to identify small mammals in bat recordings from elsewhere in Europe at least to genus, by including similar closely related species from the UK in regional classifiers for other parts of Europe. However, he needs more targeted recording of known species to be carried out in order to be able to assign these identifications to species, and to be able to build classifiers that support the sound identification of mammals more widely across Europe.

Our hopes are that this book inspires others in Europe (and further afield) to work on the sound identification of mammals, and more widely to see the opportunities that understanding acoustics can offer.

Sound Identification of Terrestrial Mammals of Britain & Ireland is published by Pelagic Publishing and is available at nhbs.com.

Book review: The Rise and Reign of the Mammals

***** Epic in scope and majestic in execution
Leon Vlieger, NHBS Catalogue Editor

Imagine being a successful dinosaur palaeontologist and landing a professorship before you are 40, authoring a leading dinosaur textbook and a New York Times bestseller on dinosaurs. Imagine achieving all that and then saying: “You know what really floats my boat? Mammals.” After the runaway success of his 2018 book The Rise and Fall of the Dinosaurs, palaeontologist Stephen Brusatte shifted his attention and now presents you with the follow-up, The Rise and Reign of the Mammals. Taking in the full sweep of mammal evolution from the late Carboniferous to today, this book is as epic in scope as it is majestic in execution.

Mammals shared our planet with the dinosaurs throughout their long reign, from the initial split of our amniote common ancestor into synapsids (us) and diapsids (them), to their extinction at the end of the Cretaceous. Over the course of some 100 million years, a parade of lineages evolved—archaic mammals all—piecemeal developing the traits we recognise as mammalian today: pelycosaurs, therapsids, cynodonts, mammaliaformes, docodonts and gliding haramiyidans, multituberculates, and therians who gave rise to today’s placentals, marsupials, and monotremes. However, the above must not be mistaken for a linear march of progress. “[M]ammals were a still unrealised concept, which evolution had yet to assemble” (p. 20). Simultaneously, it does not behove us to call these now-extinct groups evolutionary dead ends. “In their time and place, these mammals were anything but obsolete” (p. 88).

With the extinction of the dinosaurs, the rise of mammals turned into a reign. Isolated on various land masses after the supercontinent Pangaea had fragmented, they were poised for a slow-motion taxonomic starburst that would play out over the next 66 million years. In the northern hemisphere, placental mammals replaced multituberculates and metatherians and rapidly evolved into primates and the odd- and even-toed ungulates. The latter two evolved giants: brontotheres, chalicotheres, and cetaceans.

Brusatte’s strength is to bring to life the above flurry of names. What kind of creatures were they? And how can we deduce this from fossil evidence? Somewhere between chapters 6 and 7, I became awestruck by his narrative as the enormity of the mammalian evolutionary trajectory started to come into full view: bats, elephants, South American native ungulates (origins: uncertain), metatherians migrating to Australia and spawning a spectacular marsupial radiation, grazers diversified as grasses went global, and somewhere at the end, hominins evolving and repeatedly spilling out of Africa, contributing significantly to recent megafauna extinction. What a wild ride!

The macroevolutionary story is fascinating in itself, yet Brusatte makes it even better with some interesting observations of his own. We usually think of the dinosaurs as dominating the mammals, but, he suggests, this went two ways: “While it is true that dinosaurs kept mammals from getting big, mammals did the opposite, which was equally impressive: they kept dinosaurs from becoming small” (p. 95). Furthermore, DNA studies suggest that many modern mammal lineages originated back in the Cretaceous. But where are the fossils? Could some of the poorly understood archaic placentals such as condylarchs, taeniodonts, and pantodonts be the missing fossils that we have not yet been able to link to modern groups because of the lack of signature anatomical features? Excitingly, Brusatte is part of a research consortium that is building a master family tree based on both anatomy and DNA.

As in his last book, Brusatte excels at explaining complex research methods and scientific concepts. One example is Tom Kemp’s concept of correlated progression. Several times during early mammal evolution, a whole suite of anatomical, behavioural, and functional traits were changing together, making it hard to unravel what was driving what. For instance when cynodonts shrunk in size and changed their growth, metabolism, diet, and feeding styles. Then there is the revision of the mammal family tree based on DNA sequencing. The classic tree, championed by zoologist George Gaylord Simpson in 1945, was based on anatomical features. By the early 2000s, DNA-based genealogies suggested that many supposed relationships were actually cases of convergent evolution, resulting in a new classification that reflected geographical patterns rather than anatomy. The new groupings came with some tongue-twisting names: Afrotheria, Xenarthra, Laurasiatheria, and Eurarchontoglires. A final example is tooth morphology, an important diagnostic trait in this story.

What helps with these explanations are some excellent illustrations. B/w photos show amazing fossils, Todd Marshall contributes both decorative chapter headings and explanatory artwork, and Brusatte’s former student Sarah Shelley adds b/w diagrams, illustrating for instance the remarkable changes in jaw bones and how some of these were repurposed to become our inner ear bones! Woven throughout are stories of the people behind the research. Brusatte introduces both young scientists and many past scientists that are not widely known.

In what is surely a hallmark of his love and enthusiasm for the field, Brusatte’s bibliography has again been written as a narrative. It is like a chatty literature review in which he recommends books and papers, indicates where literature has become outdated, adds more technical details or clarifications, discusses where there is active debate and disagreement, and shortly touches on topics that he had to omit from the main narrative. Yes, this takes up more space than a regular reference section, and I am sure it is more time-consuming to write, but it is ever so useful. You could not wish for a better starting point if you wanted to read deeper into the technical literature.

Finally, you might be left wondering how this book compares to Elsa Panciroli’s Beasts Before Us which covered early mammal evolution up to the K–Pg extinction. There is overlap here in more than one way; Brusatte co-supervised her PhD project describing the docodont Borealestes from a Scottish fossil. I was therefore mildly surprised that he does not mention her book. There is some inevitable overlap as both books walk through the same groups, though Brusatte provides a fuller picture by covering mammal evolution up to today. Panciroli’s book stands out for its fantastic writing, though, so you cannot go wrong by reading them both.

The Rise and Reign of the Mammals is a more-than-worthy successor to The Rise and Fall of the Dinosaurs. Brusatte convincingly shows that the evolutionary story of mammals is just as fascinating—if not more so—as that of the dinosaurs.

Interview with Jan Collins: Bat Surveys for Professional Ecologists 4th Edition

Purple cover for Bat Surveys for Professional Ecologists with lots of images of bats.The 4th edition of Bat Surveys for Professional Ecologists: Good Practice Guidelines is the latest update of the Bat Conservation Trust (BCT) Guidelines and features new content on biosecurity, night-vision aids, tree surveys and auto-identification for bat sound analysis. Several key chapters have been expanded, and new tools, techniques and recommendations included. It is a key resource for professional ecologists carrying out surveys for development and planning.

Portrait image of the author Jan Collins

Jan Collins is the Head of Biodiversity at the Bat Conservation Trust and a former ecological consultant. Her fascination in bats began when participating in a bat biodiversity survey on a Vietnamese expedition in 1999 and she has worked in bat conservation ever since. She has been in her current role for the last 10 years and has played a central role in the editing and refining of the BCT Guidelines.

In this Q&A we had the opportunity to speak with Jan about some of the key aspects of the 4th edition of the BCT Guidelines and its consequences for ecologists.

What led you towards a career specialising in bats?

From a young age I was interested in being outdoors and engaging with nature. My studies followed this route, with a degree in Environmental Sciences and a Masters in Ecology and Management of the Natural Environment. I was first introduced to bats on a Frontier expedition to Vietnam in 1999 where we were trapping bats as part of a biodiversity survey. I was immediately hooked (what an amazing group of animals, with unique behaviours, and so very diverse!) and sought both voluntary and paid work involving bat conservation upon my return. I was an ecological consultant specialising in bats for over 10 years before joining Bat Conservation Trust in my dream job as Head of Biodiversity almost exactly 10 years ago now.

Grey long eared bat flying with wings spread at night with leaves in the background
Grey Long-eared Bat (Plecotus austriacus).

Could you tell us briefly about the work that the BCT does?

BCT is a dynamic, influential and growing national charity. We are the leading non-governmental organisation in the UK devoted solely to the conservation of bats and their environment. Our work represents the gold standard in bat conservation providing a lead for the rest of the world. We work to ensure that bat conservation is acknowledged as an integral part of sustainable development. Our work ranges from best practice guidance, advice and training through to engaging wider audiences so that we can get more people to understand the importance of bats and their conservation. A lot of our work also involves working with partners on the ground, local bat groups play a huge role in all aspects of our work. More information about all of our work can be found in the most recent annual review, found here or take a look at the Bat Conservation Trust Website here.

The 4th edition of Bat Surveys for Professional Ecologists: Good Practice Guidelines is due to be published in September 2023. What have been some of the key challenges in getting this ready for publication?

One of the key challenges for this edition was gaining consensus from the Technical Review Board on some of the recommendations. This included the continued use of transects for bat activity surveys and how tree surveys for bat roosts should be carried out, acknowledging the various limitations, and how approaches should be adapted to different types of projects. Another challenge has been how much to include on night vision aids such as infrared cameras. BCT are planning a kick-off meeting for a working group to develop separate night vision aid guidelines in the autumn (to include infrared and thermal imaging cameras) and therefore many aspects are still to be discussed and decided. We will also run a public consultation on night vision aids to help us to understand current practice and expectations from new guidelines on this topic.

Infrared camera setup in foreground pointed at a house in the background for bat survey
Infrared camera setup. Photo and setup by Richard Crompton.

How has the outlook for bat populations in the UK changed since the last edition of the Guidelines?

Data from the National Bat Monitoring Programme indicate that populations of the bat species we monitor in the UK are stable or recovering. However, it should be remembered that these trends reflect relatively recent changes in bat populations (since 1999 for most species). It is generally considered that prior to this there were significant historical declines in bat populations dating back to at least the start of the 20th century. This suggests that current legislation and conservation action to protect and conserve bats is being successful, and it is vitally important that this continues. Detailed information on trends for the 11 species monitored can be found in our National Bat Monitoring Programme reports here. We are also seeing signs of regional variations that deviate from the overall positive trend at the national level and we want to gain a better understanding of those. More data would help this process so we would encourage everyone to join in with one or more of the National Bat Monitoring Programme surveys. There are surveys that are suitable for anyone regardless of experience or equipment.

What are some of the key changes in the Guidelines?

A number of chapters have been expanded and new tools, techniques and recommended best practice incorporated. Below are a few of the changes but we will be developing a webinar in the coming months, detailing all of the changes so readers should watch out for that!

  • A new section on Biosecurity has been added to Considerations for Bat Surveys chapter, recognising that precautionary approaches are needed to protect both ecologists and bats from potential health risks.
  • Chapter 6 on Surveying Trees and Woodland for Bat Roosts has grown from five pages in the 3rd edition and now includes details of newer technologies and sources of information such as night vision aids, motion activated camera monitoring, The Bat Tree Habitat Key and the Bat Roost Tree Tag Project as well as updated guidelines for categorising the suitability of potential roost features.
  • Chapter 7 focuses solely on dusk emergence surveys, with dawn re-entry surveys removed as a standard approach due to the improved quality of emergence surveys with night vision aids and the variability in the time that bats return to their roosts.
  • Chapter 10 on Data analysis and Interpretation incorporates information on auto-identification systems and has a new section on data science which includes details on elements such as tidy data, minimal data requirement and data standardisation. There are also case studies to help illustrate key points.

How will the new Guidelines improve the way ecologists approach bat surveying?

The guidelines are the key resource for professional ecologists carrying out surveys for development and planning. The Biosecurity section in the 4th edition will ensure that ecologists carry out their work in a safe way, minimising health risks to both themselves and to bats. The latest edition acknowledges the constraints involved in surveying trees for bat roosts and offers different approaches to surveys depending on the nature, scale and timeline of the project. A new categorisation system for Potential Roost Features (PRFs) and trees reduces the subjectivity in initial assessments of trees. Dawn re-entry surveys are no longer recommended as there are questions around their efficacy for presence/absence and because emergence surveys can be vastly improved by the use of night vision aids. A stepwise approach is offered to those using auto-identification systems to analyse acoustic datasets and the section on Data Science aims to standardise approaches to data management. The guidelines also make reference to a wealth of resources that can be used to improve surveys and, in particular, interpretation of survey data.

Horseshoe bat hanging from a rock by its feet with its face facing the camera.
Horseshoe bat (Rhinolophus ferrumequinum).

Nocturnal survey equipment such as night vision, thermal imaging and infrared cameras are becoming more important in bat survey with the 2022 Interim Guidance Note providing clarification of their role. How will the 4th edition of the Guidelines impact the way ecologists conduct bat surveys using these types of equipment?

The 4th edition supercedes (but is consistent with) the Interim Guidance Note published in May 2022. It emphasises that surveys should usually be carried out with night vision aids and that if they are not used this should be justified in reporting, with reasons provided (e.g. at known roosts when bats are known to emerge early or in situations/locations with higher levels of natural or artificial light). Dawn re-entry surveys are no longer recommended as a standard approach because the use of night vision aids vastly improves the quality of emergence surveys, when used properly. The new guidelines state that a still shot must be taken at the darkest point of the survey to show the field of view and that appropriate illumination has been used. They suggest that the use of night vision aids can be used to reduce the number of surveyors but only if the cameras/lighting reliably match or exceed what a surveyor can achieve, with evidence provided. See the 4th edition for more information on use of this equipment!

BCT are planning a kick-off meeting for a working group to develop separate night vision aid guidelines (with much more detail) in the autumn (to include infrared and thermal imaging cameras) and therefore many aspects are still to be discussed and decided. We will also run a public consultation on night vision aids, to help us to understand current practice and expectations from new guidelines on this topic.

Bat Surveys for Professional Ecologists: Good Practice Guidelines is now available to pre-order from nhbs.com.

Author interview with Fiona Mathews and Tim Kendall: Black Ops & Beaver Bombing

Black Ops & Beaver Bombing: Adventures with Britain’s Wild Mammals is a captivating and entertaining deep dive into many of the mammals of Britain. Fiona Mathews and Tim Kendall explore mines inhabited by great horseshoe bats, go on overnight stakeouts in search of pine martens and travel from Scotland to the Isles of Scilly in search of their elusive subjects. This book puts animals at the heart of the story, revelling in their peculiarities and exploring the threats to their survival and the struggles that plague their conservation in Britain. The depth of knowledge, witty commentary and obvious enthusiam creates a beautifully written book that is difficult to put down.

Each chapter focuses on a different UK mammal, from wild boars and beavers to red squirrels and grey seals. Fiona and Tim explore the history, ecology and current conservation of these species, focusing on what is threatening them and what should or is being done to protect them. They do not shy away from giving criticism and sharing their frustration when the attitudes of policy makers stand against environmental protection and restoration. In search of answers to the problems that beset our wildlife, the authors reveal the wonder of creatures that are worth fighting for.

Fiona Mathews is a professor of environmental biology at the University of Sussex and the founding chair of Mammal Conservation Europe. Tim Kendall is a professor of English Literature at the University of Exeter and edited Britain’s Mammals 2018. They have kindly agreed to an extended interview with us, where we discuss the role of public education in conservation projects, how climate change may be impacting population recruitment in bats and seals, whether there is hope for the reintroduction of top mammalian predators, and much much more.

Could you tell us how you both became interested in mammals and what inspired you to create this deep dive into the mammals of Britain?

Tim: I grew up right next door to Devonport Dockyard in Plymouth. I was obsessed with spotting mammals as a child, but the only ones I ever saw were grey squirrels. When I was 8 or 9, I wrote a poem for school about seeing a badger, describing the joy and excitement I felt. It was all made up: I didn’t see a live badger until after I left for university. Luckily, I had the good sense to marry a mammal biologist and carry out fieldwork with her, which means that I’ve now seen all but three of our native mammal species.

Fiona: I’ve been interested in mammals for as long as I can remember, but I decided it should become my career after I went on my first bat walk. Black Ops and Beaver Bombing was partly inspired by my work reviewing the population status of Britain’s mammals and drawing up the Red List with the Mammal Society.

The preface, I-Spy, makes an interesting point about the interconnectedness of species as well as the focus of conservation: “If you want to save the barn owl, start by saving the field vole”. Do you believe the focus on ‘charismatic’ species, which are often higher up in the food chain, more often aids the conservation of prey species (such as by increasing or improving habitats) or harms these species by increasing the population of their predators? Should more conservation projects take a more ‘grassroots’ focus, by helping species lower down on the food chain?

We ignore the small species at our peril, and the fact that they’re almost all in decline is deeply worrying. Of course, wolves and wild cats grab the headlines, but if we don’t pay attention to the bioabundant species, everything across the food web is affected. We talk a lot in the book about the Scilly shrew, and if we’d thought anyone would read it, we’d have included a chapter on field voles.

In Chapter 3 ‘On the Trail of the Lonesome Pine Marten’, you discuss the extensive work done to win over the local people before the ‘recovery’ project began. Do you believe the public will become more and more open to these types of projects or will public education always need to play such an extensive role?

The general public is already becoming more welcoming, but the people who control landscapes are a small subset of the population, and they often have their own priorities that they believe (rightly or wrongly) will be damaged by reintroduction and recovery projects. One of the unfortunate things about rewilding is that it’s becoming as divisive as Brexit. We should all be working together to reverse the biodiversity crisis.

Wild mammals only make up between 2–4% of the world’s mammal biomass, decreasing by more than 85% since the rise of humans. In contrast, livestock makes up more than 63% of mammal biomass. How has this drop in wild mammal biomass impacted ecosystems and do you think we’ll be able to repair this?

High intensity livestock production is undoubtedly a massive contributor to biodiversity loss, but we mustn’t perceive farmers as the enemy. We need good farmers producing good food and getting rewarded for sustainable and wildlife-friendly production. Progress towards reforming agricultural subsidies has moved at glacial speed. Our government, like most across the globe, is much too heavily influenced by the lobbying of large agribusinesses which want to preserve the status quo.

In Chapter 5 ‘Hanging Out with Greater Horseshoe Bats’, you mention that Fiona is working on a long-term plan to re-establish the British population of the greater mouse-eared bat. Could you tell us a little bit more about how this process would work?

Fiona: Historically, the greater mouse-eared bat has been found in Dorset and Sussex, but with climate change we would expect its range to shift northwards. There are large and thriving colonies in Brittany and Normandy at the moment. We have to work out whether they will arrive in England under their own steam, or whether we need to give them a helping hand. Translocating bats isn’t easy. I’ve set up a working group at Eurobats to bring together experts looking at the best way forward.

You mention that the greater horseshoe bat population has stabilised and is now increasing in Britain. Why do you think this is happening?

The species is struggling across mainland Europe but it has responded well to a series of mild winters in England and Wales. Organisations like the Vincent Wildlife Trust have done a fantastic job to protect and improve roosts. We should remember, though, that greater horseshoes once had a range that extended to the east of England, and it’s estimated that there was a population of 300,000 at the end of the nineteenth century. The current population is about 4% of that total, which is a remarkable recovery from their lowest levels, but we need to be aware of shifting baseline syndrome before we celebrate the good news too enthusiastically.

Chapter 5 also mentions a new system for monitoring bats, which monitors the flight paths using radio receivers. Do you think that, by highlighting important flight paths, this system will be able to be used to reduce the impacts of new developments?

Although legislative protection means that we now know a lot about bat roosts in buildings, there’s not much point protecting a roost if the animals lack places to forage or mate. New techniques such as static radio tracking allow us to identify important sites and protect them for the future.

As cool weather in spring can have an impact on the growth and development of young bats, has climate change impacted juvenile survival rates and population recruitment?

We know that baby bats grow less well, with short- and long-term consequences, when weather conditions are poor in the breeding season. We would expect to see negative effects from climate change, and this is something we are currently looking at in a European-wide project. The challenge is that few researchers have datasets that span at least 20 years, which is the timeframe you need for analysing these long-term trends. So we’re also conducting other research on shorter timescales to assess whether mother bats are moving around their roosts to select different temperatures.

Chapter 6 ‘Tiggywinkle Goes Rogue’, mentions how ‘tidiness’ harms biodiversity. Do you think the growth in recent campaigns such as No Mow May will help to reduce society’s obsession with garden ‘neatness’?

Yes! It also requires us to hassle our local councils until we outnumber those strange people who complain about overgrown verges. Councils will take the path of least resistance, which should be to do as little ‘tidying’ as possible.

A common threat for several of the species you cover in Black Ops & Beaver Bombing is light pollution. Is there momentum at the moment that would see light pollution effectively combated in the coming years?

No, and the problem is worsened by the fact that lighting is getting cheaper and more intense. It’s frustrating because light is one of the few pollutants that simply disappears as soon as you flick a switch.

In chapter 7, ‘Who Cares What Colour the Squirrels Are?’, you mention that certain conservation strategies, such as the culling of grey squirrels to protect red squirrels, are unlikely to receive funding due to fears of adverse publicity. How much do you think conservation strategies are affected by how palatable they are to the public? Do you think this impacts the effectiveness of some conservation projects?

The biggest issue is the insatiable appetite for novelty over longevity. Nobody wants to fund routine maintenance. You may get grant money to reintroduce water voles, but will you still be funded to cull American mink a decade later?

As storms often lead to the deaths of many seal pups, will the increased occurrence of extreme weather due to climate change have a significant effect on population recruitment for seals on our shores?

We don’t know. In our seal chapter, we call the recovery of grey seals the great mammal conservation story of the twentieth century. Their numbers increased from about 500 during the First World War to well over 100,000, which makes up around 40% of the global population for the species. Storms and tidal surges can wipe out entire colonies of pups in any given season, but thankfully so far that doesn’t seem to have dented their population growth. Shout out to the amazing volunteers who rescue and raise pups for 6 months before they’re strong enough to be released!

The government recently released England’s first Marine and Coastal Wildlife Code, do you think this guidance will significantly help to protect wildlife such as grey and harbour seals from the impacts of visitors? 

Yes. It was long overdue, and it’s vital. Some people will remember seeing the footage of a runner deliberately chasing a colony of seals into the sea in Yorkshire. If that happens to a moulting seal or a pup, they can die. We’re all tempted to take selfies next to wildlife, but it’s rarely a good idea.

This book ends by asking why Britain cannot seem to accept mammalian predators in the way that European countries have. Do you think there is hope for change in attitudes that could see the re-introduction of species such as lynx, wolves and bears within the coming decades?

We end the book in the Abruzzo National Park, 90 minutes drive from Rome, where there are now about 11 active wolf packs and 50 bears. The Cairngorms is ten times bigger, and has roughly the same human population. So much for the argument that we’re a crowded island! So we could and should reintroduce these apex predators, but we have to deal with misinformation from (for example) the current President of the National Farmers’ Union, who claims that lynx would pose a threat to ramblers. No wild lynx has ever attacked a human. Cattle, on the other hand, kill 8-10 people a year in Britain.

Do you have any future plans that you could tell us about?

We’ve just started a podcast, ‘Mammals R Us’ (https://rss.com/podcasts/mammalsrus/). We have very different working habits, so our big question is: can we finish another book without getting divorced?

Black Ops & Beaver Bombing by Fiona Mathews and Tim Kendall was published by Oneworld Publications in April 2023 and is available from nhbs.com.

Author interview with Michael Stephen Clark: The Fragmented World of the Mongoose Lemur

The Fragmented World of the Mongoose Lemur is a book about a critically-endangered species, fractured ecosystems and the global war on nature. It is a compelling story in which author Michael Stephen Clark reveals the fundamental paradox of the mongoose lemur’s natural history.

In this post we chat to the author of this important and timely book about his work with mongoose lemurs, the problems withthe way that conservation is reported in the mainstream media and his hopes for the future given the alarming loss of biodiversity and rate of extinctions we are currently experiencing.

Author Michael Stephen Clark

Your book is described as a modern natural history, but it also conveys a larger message that is of relevance to our relationship with all wild species. Why did you choose the mongoose lemur as your focal species – what is it about this primate that makes it suitable for illustrating more widespread issues?

I first became interested in the mongoose lemur when I worked with an aged and overweight pair at London Zoo in the 1980s and 1990s. They were being kept off-exhibit, which I thought was inappropriate given their endangered status. In due course, we were able to move them into a larger, outdoor enclosure, but only after an operation had been performed on both of them to remove excess adipose tissue. It was all very invasive, but the animals were much fitter, healthier and happier as a result. Shortly afterwards, I discovered that the captive breeding programme for the species lacked co-ordination, so I established the first international studbook for the species in captivity. There wasn’t a great deal of information about them in the literature and relatively few researchers and institutions had sought to remedy that. It quickly became clear to me that the mongoose lemur was fast becoming undervalued and potentially overlooked as an endangered species. I’ve been concerned about them ever since, probably because my sympathies often lie with the ‘underdog’.

I’d long been aware that the mongoose lemur could illustrate very directly the profound disruption caused by human alteration of the natural continuum. Human attitudes to wildlife contain a raft of contradictions that result in contradictory outcomes. This is particularly true of the mongoose lemur. In common with virtually all lemurs, it is a critically endangered species that exists in compromised and/or fragmented habitat in the wild. Perversely, however, it appears (on the surface) to be more numerous and relatively safe as a naturalised alien species on the Comoros Islands of Anjouan and Moheli. Lemurs in captivity are generally viewed as a conservation priority, yet the mongoose lemur ranks lower in importance than some of the more enigmatic lemur species. Already, without digging too deeply, we can see that the mongoose lemur has experienced displacement at every point where it has come into contact with humanity.

Perhaps, more alarmingly, the mongoose lemur has unwittingly become a prima-facie example of something disquieting; namely, a growing acceptance that nature will be allowed to persist only in places of our choosing. It’s a situation that has led to questionable decisions around relocation, translocation, restoration, rewilding, and re-introduction. To my mind, these things invite compromise, not least where species such as ring-necked parakeets in England and mongoose lemurs on Anjouan are inter-changeably considered wild, free-living, native and/or naturalised. These compromises ominously signpost natural systems by human design. Presently, the momentum is behind stand-alone programmes, projects and initiatives that are, of necessity, limited in scale. This may well lead to the ultimate breakup of biodiversity and an end-point where our natural world has become little more than a ‘zoo in the wild’.

Do you think that the way conservation and the plight of endangered species are reported by the mainstream media is problematic? I’m thinking, for example, in terms of how the public, conservationists and governing bodies might go on to perceive the state of the natural world as a result?

I actually think it’s a massive problem for conservation. Once upon a time, the adage was ‘there’s no such thing as bad publicity.’ In recent years, the mainstream media has shifted away from the substantial to the superficial reporting of wildlife conservation matters. Social media and the wider online milieu all feed into that, of course, but far too many stories are either half-told, poorly-told, or just plain misleading. It’s actually worse than not telling the story at all. This is especially disruptive for governing bodies and NGOs that can so easily find themselves painted into a corner by media-generated hubris. I’m not sure that a proliferation of conservation news portals, websites, blogs, podcasts and influencers is useful either. It is more likely that conservation stories will become even more distorted, diluted and diffuse as result.

I think the effect of all this on the public, among conservationists, and within governing bodies is potentially quite dangerous. It could make identifying priorities and taking effective action a minefield of conflicting imperatives. The recurring controversy over the Ramsar site at Coul Links in Scotland is a good example of media hubris threatening not only to drown out voices of reason, but also to trample the letter of the law into the ground. It took the combined firepower of a self-generated media campaign by a coalition of Wildlife Trusts and NGOs to beat back an existential threat to unique (and legally protected) dune habitat. I suspect that such coalitions will have to establish permanent media entities if they are to fight the war on nature across several (media) fronts.

Given the alarming rate of extinctions and global diversity decline, what would you like to see happen, both on a local and an international scale, to begin dealing with this? And would you describe yourself as broadly hopeful or pessimistic about this crisis?

I’m afraid that I am neither optimistic nor pessimistic about the future. I know it’s a cliché, but I think the future is already here. The important decisions now (as ever) will lie with young people, many of whom are not only well-educated and eminently qualified, but savvy as well. I recently rejoined Linkedin after a long absence and the sheer number of extremely active, professional wildlife conservationists around the world is really quite dazzling. In the short-term, issues around job security, personal security, career development, and establishing substantial permanent facilities in the field need to be addressed.

Frankly, I think that’s primarily the top-down responsibility of pan-national institutions such UNEP and the World Bank. The scale of accelerated extinction events forewarns us of a looming biodiversity crisis that could very easily become an existential threat in just a couple of generations. It requires a global response and the money really has to start flowing from global institutions if we are to empower and support our highly motivated international conservation professionals. To my mind, food security, health, climate, biodiversity and species conservation are equal priorities. I don’t understand how this became a hierarchy of aspirational goals because the response they all require is equally urgent.

In the medium term, it is not news to say that we have to invest in future generations, but ‘hope and inspiration’ aren’t enough. I think that young children generally receive a good grounding in natural history in their pre-school and primary school years. With a little support, that can happen in a developing country as easily as it can in the UK. But, young people need to have pathways they can follow in order to learn more. From there, they can gain a rounded understanding of natural history, which would inevitably include an elementary form of conservation biology. I’m a bit surprised that some of the more prominent NGOs aren’t lobbying for this with a draft curriculum. Nature conservation education for school-age children has to graduate from photocopied fact-sheets and elevate itself as the most valuable ‘eco-system service’ available.

As a zoological professional you have studied and worked in several esteemed organisations including the University of Bristol, London Zoo and Oxford-Brookes University. What do you consider to be the most significant highlights of your career so far?

Anyone who has ‘hands-on’ experience of working with wild animals in the field and/or captivity will tell you it’s a life full of great highs and lows. It doesn’t do to dwell on the lows so I’ll concentrate on things that I considered achievements. As I explain in my book, the time I spent on Anjouan in the Comoros Islands was a very special career highlight. It was a great privilege to be trusted with the capture and care of Pteropus livingstonii, one of the rarest bat species in the world and, of course, to encounter free-living mongoose lemurs first-hand. I’m especially gratified that several papers, features and articles that I authored or co-authored were published in the course of my work at the Zoological Society of London. These included my account of mongoose lemurs on Anjouan, the jointly written history of black-footed penguins at London Zoo, and a report on breeding Leadbeater’s Possum at London Zoo. Getting up close and personal with urban foxes and badgers in the course of fieldwork for Professor Stephen Harris at Bristol University was memorable, and I very much enjoyed my brief role as a visiting lecturer at Oxford-Brookes University. It was quite an honour to be there at the beginning of the now prestigious Primate Conservation MSc course.

The Fragmented World of the Mongoose Lemur is, in large part, a species-specific natural history – a format that is perhaps less popular than it has been in previous years and decades. The book was also published independently. How did you find the process of planning, writing and publishing the book and what were the main challenges you faced?

It’s correct that the species-specific natural history books have fallen out of favour with mainstream publishers, but I’m not convinced that readers feel the same way. In (apparently) normal circumstances, the life history of a species will appear to be relatively constant. In natural history classics such as David Lack’s ‘Life of the Robin’ and Sarah Churchfield’s ‘Natural History of Shrews’, the subjects live in a self-contained world that is full of challenges, yet seems immutable. The world today, in the age of the Anthropocene, rarely allows for ‘normal circumstances’. Wild animals will live, prosper, suffer, die or become extinct largely at our discretion, which means that their life histories now have to take account of the rapid, ongoing changes wrought by hyper-accelerated, unregulated human activity. That’s why I think it’s valid to revisit species-specific natural history writing and place it in a much wider context.

There was a time when my book would have been titled ‘The Mongoose Lemur in its World’, but that world no longer exists. It more accurately lives in a fragmented world of our making. This is happening to species the world over and those that are able to adjust may live, while those that can’t will surely disappear. We need to understand what makes the difference between the two potential outcomes in order to construct a meaningful response. I think this can emerge from species-specific natural histories that draw from a deeper well of scientific, philosophical and practical resources. I think it’s too often wrongly (and condescendingly) assumed that readers either can’t or won’t respond to stories that cast the net widely and speculate, as I have done, about ‘Propects and Perspectives’.

I’m fairly comfortable now with the process of independent publishing and I’ve never seen it as a poor relation to using an established publishing house. I would describe it as a slow, gentle learning curve rather than a steep and arduous one. The early stages of planning and writing are the most fun, but luckily I quite like editing, proofing and polishing too. I’m quite experienced in that regard but I find that editing your own work means that you really can’t rush it. Familiarity breeds oversight. I usually keep sharing with others to a minimum, but for this book I got a lot of help on specific chapters. I needed it too, and their input was invaluable as the acknowledgements section of the book will attest.

If I had to identify a single challenge that was really testing, I would say that maintaining a consistent, balanced style of writing throughout gave me the most sleepless nights. I wanted to hold the reader’s interest with an engaging narrative but still maintain a firm grip of the factual material. I also wanted the book to be a bit provocative. I always think I’ve read a good book if it leaves me with as many questions as it does answers.

Finally, what is in store for you next? Do you have plans for further publications?

At the moment, I’m doing the preparatory work for events in support of the book. I’ll be using my original colour slide transparencies from Anjouan to illustrate my presentations and I recently bought a very old colour slide projector for that purpose. It’s a bit quirky, I know, but I think it will make things a bit more interesting.

In terms of writing and publishing, I have a couple of things of my own in development, but I’d be interested in collaborating with others to produce further modern natural histories. I’d like to keep the focus on primates, mainly because they’re exposed to lots of different pressures in a variety of situations where they come into close contact with us humans. Their stories challenge us to think about the relationships we have with nature generally and how we are going to rescue biodiversity from our worst excesses. Species such as pygmy slow loris, Cat Ba langurs and Kirk’s red colobus spring to mind, although there are countless others.

Print-on-demand and increasingly accessible typesetting software mean that there are few obstacles to producing books like this. If there is a problem then it is persuading authors to enter a publishing relationship that is unconventional, yet fairer and more equable than the conventional model. Publishing independently also means that your book need never go out of print, something that frustrates many published writers who find themselves out of contract.

The Fragmented World of the Mongoose Lemur by Michael Stephen Clark is available now from NHBS.

In The Field: Batbox Baton Bat Detector

The Batbox Baton is an economical and user-friendly bat detector ideal for newcomers to bat detecting and bat detecting enthusiasts alike. The Baton is perhaps one of the most simple and easy-to-use bat detectors on the market, so simple that it can be operated with a single button. With simplicity often comes sacrifice, but not in the case of the Baton. This device uses technology called frequency division which enables the user to monitor all ultrasonic frequencies between 20kHz and 120kHz at once by dividing the frequency by a factor of 10. If a bat calls at 50kHz, for example, a 5kHz form will be played through the speakers. This means no tuning is required and the user is not at risk of missing any bats by being tuned to the wrong frequency.

We took out a Batbox Baton to a rural lake in Hampshire at dusk on a dry August evening. The detector comes preloaded with a battery, and with a flick of the single On/Off button we were listening to bat calls in a matter of seconds. The detector is extremely lightweight, ergonomic and compact, making it easy to carry into the field. The calls of (what we believe were) Soprano Pipistrelles were divided down to an audible frequency and we could hear multiple individuals calling and hunting above us. It is worth noting that species identification can be more difficult without a frequency display screen, especially if the user has less experience in hearing calls in frequency division or if they are unable to compare with other bat calls. We found the Baton a very useful tool for listening to bats for pleasure and the lack of a screen or tuning dials means you can focus your eyes above and watch the bats as they fly and hunt. 

Should the user wish to get a bit more out of their bat detecting experience, however, the Baton does provide options. The Baton has a ‘Line Out’ socket, and when connected to a laptop with a soundcard via a stereo lead, and used in conjunction with the free BatScan analysis software compatible with Windows only, real-time sonograms can be viewed in the field allowing detailed analysis and species identification. 

The Baton’s Line Out socket can also be used with a digital audio recorder, such as a H1n Handy Recorder, and calls can be recorded for future analysis using the same BatScan software. It should be noted that if the user wishes to listen to calls through headphones, this cannot be done through the detector itself but only via the audio recorder. The use of a recorder and further analysis with BatScan software allows the user to gain a detailed understanding of call structure and species identification, and further their enjoyment of bat detecting. 

Whether you have been enjoying bat detecting for years, or you are just looking to start out, the Batbox Baton will have something for you. It is an economic and versatile option that we would not hesitate to recommend.

The Batbox Baton Bat Detector can be found here. Our full range of bat detectors can be found here.

If you have any questions about our range or would like some advice on the right product for you then please contact us via email at customer.services@nhbs.com or phone on 01803 865913.

Owl Pellet Dissection

Owl pellets contain all of the indigestible parts of the prey. Image by Gail Hampshire via Flickr.
What is an owl pellet?

Owls feed on a variety of prey; most commonly small mammals but also birds, frogs and other small animals. These prey items are consumed in their entirety and, while the flesh is digested by enzymes, the owl is unable to digest the harder parts of the body, including the teeth, bones, fur or feathers. These indigestible parts are regurgitated as a pellet. Unless they are very fresh, pellets are dry, light and odourless.

In this article we will look at where to find owl pellets and how to tell which species of owl they came from. We will also provide some tips on how to dissect a pellet, how to group the bones into types, and how to identify some of the main species of small mammal that you will find in pellets in the UK.

Where to find owl pellets

Owl pellets can frequently be found wherever owls nest or roost. Good places to search are at the base of tall trees within woodland areas, or in barns or outbuildings where owls are known to roost. Please be aware that you must not disturb breeding or roosting owls in order to collect pellets. Barn Owls in particular are protected in the UK by law under the Wildlife & Countryside Act 1981 and their breeding sites must not be disturbed under any circumstances.

If you don’t have any luck finding your own pellets or don’t have access to places where you might find them, there are several places online where you can order some. Reputable sources in the UK include the Barn Owl Trust and the Suffolk Owl Sanctuary.

What species of owl is my pellet from?

There are five resident species of owl in the UK: Barn Owl, Tawny Owl, Little Owl, Short-Eared Owl and Long-Eared Owl. All of these species produce pellets that are relatively easy to tell apart, particularly if you also know the habitat where they were found. Below is a brief guide to their main characteristics.

• Barn Owl: pellets usually measure 3-7cm in length and are rounded at both ends. They are fairly dark in colour and have a smooth surface.
• Tawny Owl: pellets measure 2-5cm in length and are narrow and bumpy, often having tapered ends. Greyish in colour and sometimes furry looking.
• Little Owl: pellets are fairly small measuring only 1.5-2cm in length. Long and narrow with a soft crumbly texture.
• Short-Eared Owl: pellets are fairly large, measuring 3-6cm in length. Narrow with one rounded end and one tapered end. They are grey and smooth and very lightweight.
• Long-Eared Owl: pellets measure around 2-4cm and are narrow and bumpy. Usually grey in colour.

The most common pellets you will find in the UK are from Barn Owls.

Barn Owl pellet with mounted needle and fine pointed forceps.
How to dissect an owl pellet

There isn’t much equipment you need to dissect an owl pellet, but a few items will make the job a bit easier:

• Mounted needle: this is useful for teasing out fur from around the bones, and moving around delicate specimens. A cocktail stick or needle pushed into a cork will also do the trick.
• Forceps/tweezers: helpful for picking up bones and particularly for removing fur from inside skulls. Forceps with a fine point are best.
• Magnifying glass/hand lens: a small magnifier will allow you to get a closer look at the bones that you find. Jaw bones in particular are very useful for identifying the species and a magnifier will help you get a better look at the arrangement and structure of the teeth.
• White paper/card and glue: it can be helpful to arrange your bones by type onto a sheet of white paper which you can then write on when you have decided what they are and who they belong to. If you would like to make a permanent ID aid you can also glue them onto a piece of card and add permanent labels.

How to identify the contents of an owl pellet

The first thing you will need to do is to tease apart the pellet and separate the bones from the fur and feathers that are holding it all together. To begin with it is easiest to gently break the pellet into several smaller sections then work on each of these in turn. Use your fingers as well as the forceps to carefully tease apart each section, removing any bones and placing them to one side for identification. If your pellet is very hard and dry, try soaking it in water first to soften it.

Once you have all of the bones from your owl pellet, try to group them into types on your sheet of paper. The most common bones you will find are the following:

  • Skulls: for mammals, this consists of the top part of the skull and upper jaw, along with the lower jaw, although this is likely to become detached once you have cleaned all of the fur and other material from inside. For bird species this will include the upper and lower parts of the beak.
  • Back legs: includes the thigh bone (femur) and the lower leg bones (fibula and tibia)
  • Front legs (arms or wings): includes both upper (humerus) and lower (radius and ulna) bones
  • Hip bones
  • Shoulder blades (scapula)
  • Back bones (vertebrae)
  • Ribs

The image below illustrates typical examples of each type of bone. You can also download a useful bone identification sheet from the Suffolk Owl Sanctuary website.

 

The most useful part of the skeleton for identification is the skull and jaws or beak. Bird skulls will obviously be very distinct from those of mammals due to the presence of the beak, so these can immediately be separated out. For the remaining mammal skulls, however, we will need to take a closer look at their lower jaw bones and teeth.

In the UK the most common small mammals you will find in owl pellets are voles, mice and shrews. It is very easy to distinguish which of the lower jaws belong to shrews as they have a continuous line of teeth from the front to the back of the jaw. This is because shrews are insectivores and chew their food, much the same as we do. Voles and mice, however, both gnaw their food, and have a big gap between the long front tooth and the back teeth.

To tell the difference between voles and shrews, we need to take a closer look at their back teeth. Voles have teeth with distinctive grooves down the sides.  In those of a field vole, the grooves run all the way down the side of the tooth. There is also no obvious root. Bank voles have grooves which only run part-way down the side of the tooth and they have two obvious roots, similar to those of a human tooth. The back tooth from a mouse jaw is much smaller when compared to a vole and its structure is much more similar to that of a human tooth. It also has two roots. This sheet from the Barn Owl Trust has a great illustration of the various small mammal lower jaws with size guidelines to help with identification.

Hopefully this article has been a useful introduction to owl pellet dissection and the identification of some of the most common prey species contained within them. If you want more help with identifying all of the bones in your pellet down to species level, the guides listed below are invaluable. Once you have categorised all of the bones you can attach them to a piece of card with permanent labels or arrange them to create a complete skeleton of each species.

Finally, don’t forget to wash your hands well when you have finished your dissection. Any pellet remains can be safely composted.

Further reading

Guide to British Owls and Owl Pellets

This fold-out chart includes colour paintings of the five species of owl permanently resident in the British Isles, shown both perched and at rest. Also included are illustrations and written descriptions of the different pellets that may be found, and a systematic identification key to their contents, including complete skulls, jaws, teeth and other recognisable bones and animal parts.

 

The Analysis of Owl Pellets

This booklet will not only enable you to identify what you find in the pellets of British owls, but also shows how the data may be usefully presented and how to estimate the actual weight of food the birds have eaten.