30 Days Wild Activities – Bat Walk

The hours around sunset are the best time to see and hear bats. Image by O Haines.

Looking for some inspiration for activities during 30 Days Wild? Why not take a stroll around sunset and see if you can find some bats. If you have a bat detector then you can also listen to the ultrasound calls they produce and have a go at working out which species you’re seeing and hearing. Plus, an evening walk also gives you a chance to see what other nocturnal animals are out and about – owls, foxes, badgers and toads are all more active at night and, if you’re lucky and in the right place, you might also be fortunate enough to hear a Nightjar.

 What you need:
The Echo Meter Touch 2 connects directly to your phone or tablet.

• Bat detector – For beginners, a heterodyne detector is a great choice as they are economical and easy to use. Simply tune it to the frequency that you want to hear and then listen through the speaker or with a pair of headphones. If you want something a little more advanced, the Echo Meter Touch 2 connects directly to your phone and lets you view and record the bat calls, as well as suggesting the most likely species that you’re listening to. (If you don’t have a bat detector, you can still go for a walk at dusk and look for bats flitting beneath the trees and across the surface of the water).
• Torch – Not for seeing the bats but for finding your way safely in the dark!• Warm clothing and sensible footwear – Make sure you have enough warm clothes for when the temperature drops after sunset, and footwear that’s suitable for the chosen terrain. A thermos with a hot drink is also a good idea!
• Guide to bat frequencies – If you’re less familiar with bat detecting then a list of the frequencies at which you are most likely to receive the strongest signal for each species is a good thing to have with you. This simple pdf can be printed out to carry with you, or why not take a look at this guide from the Bedfordshire Bat Group for more detailed information on identifying bats using a heterodyne detector. The FSC Guide to British Bats is also a good choice and provides lots of information on identifying bats in flight.

When to go:

Bats are most active from April to September and the best time of day for seeing and hearing them is around sunset. If you’re walking to a location where you will be using your bat detector or hoping to see bats, then make sure you set off with plenty of time to get there before the sun sets. And don’t forget your torch – even though it will be light when you set out, you’re likely to need it on the way home.

Where to go:
Woodlands, parks and gardens are all good spots to look for bats. Image by O Haines.

Parks and woodland, especially those with aquatic areas such as ponds and lakes, are great places to find bats. If you can find a walk that covers a variety of habitat types then this will increase your chances of seeing/hearing more than one species. Make sure that the route you choose is safe and accessible and that you know where you’re going – places can look very different at night than they do in the day and it’s easy to lose your sense of direction if you’re not on a clearly marked path.

If you don’t want to venture far from home, then you can also look and listen out for bats in your garden. Near hedges or trees is usually a good place to focus your attention.

What to do:
The Magenta Bat 5 is ideal for bat walks

Once sunset is approaching, simply turn your bat detector on, keep as quiet as you can and watch and listen for any bats. The earliest species to emerge tend to be the pipistrelles and noctules. Of these, common and soprano pipistrelles are the most frequently seen. For this reason, it is worth setting your detector to 45 or 55kHz (or switching between the two periodically) to see if you can pick up any sounds. If you can see bats flying but don’t hear any sounds at these frequencies, then try scanning through all frequencies slowly to see which produces the most significant and clear response.

Daubenton’s bat. Image (a).

If you are near water and see bats skimming the surface, then these are likely to be Daubenton’s bats. As with the common pipistrelle, Daubenton’s bats produce the strongest echolocation signal at around 45kHz. (They also tend to emerge later than pipistrelles, so you may have to wait until later in the evening to catch a glimpse of these!).

Once you become used to using your detector, you will become accustomed to the different types of noises produced by different species and, in combination with where and how the bats are flying, will become more confident in deciding which species you are looking at and listening to.

Find out more:

If you want to find out more about bats, the Bat Conservation Trust website is a great resource and offers information on all 18 species of bat found in the UK. They also provide a list of local bat groups and coordinate the National Bat Monitoring Programme. Surveys cater to different levels of experience and knowledge and are fun and rewarding to carry out. Some don’t require any equipment, so you can take part even if you don’t own a bat detector.

Head over to nhbs.com for our complete range of bat detectors and take a look at our blog post for more tips for beginners

The RSPB website is a great place to hear common bird songs and will help you to distinguish between different types of owls. The most common species you are likely to come across are Barn Owls and Tawny Owls. You can also hear an example of a Nightjar call on the website. 

Further reading:

A Guide to British Bats
#129064

This fold-out guide includes 16 species of bats that live and breed in Britain and has two parts: a guide to identifying bats in flight using bat detectors, flight patterns, size, habitat and emergence time after dusk; and a key labelling the different body parts of a bat for identifying them in the hand.

 

The Bat Detective
#79534

This book takes the reader through both the theoretical and practical aspects of the use of the bat detector and covers all aspects of bat identification in the field, including `jizz’, flight style, foraging behaviour, roost finding, echolocation, and basic survey technique. As each topic is explained, references are given to the relevant tracks on the CD.

British Bat Calls
#181961

Covers topics such as the properties of sound; how bats use sound; bat detection methods; recording devices; analysis software; recording techniques and call analysis. For each species found in the British Isles, information is given on distribution; emergence times; flight and foraging behaviour; habitat; and echolocation.

 

Image credits:
(a) n51_w1150 from the Biodiversity Heritage Library via Flickr

Author Interview: Neil Middleton, Is That a Bat?

Neil Middleton is the owner of BatAbility Courses & Tuition, a training organisation that delivers bat-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. Neil is the lead author of the popular Social Calls of the Bats of Britain and Ireland (2014) and in 2016 he wrote The Effective Ecologist which tackles the challenges facing ecologists as they endeavour to perform to the highest standard within their working environment.

His latest book, Is That a Bat?, published in January, provides a technical, yet accessible, guide to understanding and categorising non-bat sounds. Including a downloadable audio library, this ground-breaking book is designed to help bat workers be more confident in analysing their recordings, and also discusses the wider conservation benefits of studying non-bat sounds.

We recently caught up with Neil to chat about the book and about nocturnal sounds and their analysis.

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Where did the idea for this book come from? And do you feel that this is a subject/area of study which has been largely overlooked?

The idea came from a number of different directions during the years prior to my starting work on this project. As someone doing lots of sound analysis for bats and also seeing the kind of queries that would get sent to me, it was apparent that bat workers spent at least some time, unproductively, trying to work out what species of bat it was, when it turned out not to be a bat at all.

Additionally, whilst working in darkness we often hear other sounds that get ignored or written off as ‘of no interest’. These sounds (eg a Schedule 1 bird species) could actually be very relevant to the project we are working on and the reason why ecologists are being sent to a site in the first place.  Saying ‘I don’t know. It’s not a bat, so it doesn’t matter’ isn’t really the best approach to take. When people see something, they tend to react more positively, as opposed to when they hear an unfamiliar sound. In darkness, however, sound is usually all you get. So, this put ‘in the frame’ the thoughts I had regarding audible sound encountered during darkness.

Finally, I had been asked many times over the years, questions such as, ‘do mice make high frequency sounds?’  Until relatively recently I didn’t have a proper answer to that question and probably, to be honest, didn’t even think that I cared or that it mattered when it came to doing bat work. I could not have been more wrong.  Not only mice, but all of our small terrestrial mammals make ultrasonic sounds that can get picked up by bat detectors, and many produce sounds that are quite similar to some of the echolocation pulses or social calls produced by bats.

Having written this book (and completed the immense amount of research that it has inevitably involved) do you now find yourself looking at and treating your own recorded data differently?

Oh yes, most definitely. I am now very nervous about being certain about anything slightly unusual. When I deliver presentations, I often use the expression, ‘You only know what you know’.  I feel this underpins my whole thought process now, as it also follows therefore that ‘You don’t know what you don’t know, and how much there is still to find out’. I honestly think, in some respects, we are only scratching the surface when it comes to our knowledge of bat-related sound, as well as all of the other species and things that make noise within a bat’s soundscape. I think we are sometimes far too sure of ourselves for our own good.

Following on from that, it also has consequences to our, sometimes misguided, reliance on automated classifiers. I get quite unsettled when I hear some people talking about complex stuff (eg separating Myotis species with high degrees of confidence) in such an authoritative manner. I have always preferred a more cautious approach, and even more so now. If anything, having now done this project, I would say that I have backtracked, in some respects quite far, from stuff that I once thought I knew reasonably well.

How do you feel about auto-ID software? Do you have concerns that it gives users a false sense of confidence in their results? And do you feel that, as technology becomes more advanced, it might be at the expense of expertise in both fieldcraft and analysis?

To answer the last part of this question first, yes on both accounts. I go into quite a lot of detail within the book as to why I think this way. The pages in the book regarding these areas were written and revisited many times during the process. When I look at my first draft of those pages (which I still have) it is interesting for me to see the journey I have been on and how my thinking changed during the process.

My viewpoint on automated classifiers at the start was quite negative in all respects. In some respects, the classifier challenge isn’t related purely to bats. If only it was, it would be so much easier. I was horrified to find classifiers confidently identifying lots of non-bat-related sounds as bats. This was the point for me where this work moved well into the ‘essential reading for bat workers’ category, as opposed to a ‘nice to know’. I remember that day extremely well. I was in a hotel room, near Gatwick, doing analysis of harvest mouse calls. They looked a bit like common pipistrelles, and the three classifiers I used that day all agreed! After publication, I was especially pleased to see that some of the reviews have very much labelled it as ‘essential reading’, for a number of reasons (ie not just the scenario discussed here).

But putting all that aside, for the moment, my final conclusion (for the time being?) is that there are definitely better classifiers than others, and there are different ways in which classifiers do things that will produce different results. I also feel that classifiers used sensibly, by experienced people (ie those who possess all the ‘essential’ knowledge), with audits in place, can be extremely powerful and useful. However, just like a human, a classifier has got so many things loaded against it arriving at the right answer (much of which is discussed in the book). So, it is fair to say that classifiers can come up with completely wrong answers. It is also fair to say that humans, even with experience, can also come up with completely wrong answers.

Therefore, neither approach is perfect, but the thing I now feel strongest about isn’t the classifiers themselves but, firstly, the lack of training people get in understanding how these systems work ‘behind the scenes’. And secondly, the lack of technical knowledge and experience of bat-related acoustics demonstrated by some of those who use these systems. I think it is too easy for organisations to give this important and often complicated work to junior members of the team, furnishing them with classifiers etc. It is then as easy for an inexperienced person to use these systems, write reports and influence decisions that are being made, without they themselves (or their bosses) appreciating that perhaps they or the classifier is getting it wrong (back to ‘You only know what you know’). Ultimately, during any project, the human decides (or at least they should). They decide what classifier to use. They decide the methods to use. They decide to blindly accept what the system is telling them, or not. They decide to do a proper manual audit of the results, or not. They decide what goes into a report and whether or not to be cautious with their interpretation. In the book I say something along the following lines:

‘Our bat detectors and associated software should be regarded as educated idiots. Very intelligent, but on occasions totally lacking any common sense. There is one part of the process, however, where ‘common sense’ needs to be applied. This is the part where a human decides what to do next. You need to keep pressing that ‘Common Sense’ button before jumping in with wrong conclusions and inappropriate decisions.’

Too many people blame a classifier for making mistakes, when in fact we should perhaps be collectively looking in the mirror. It is a tool, and like any tool there are right ways and wrong ways, right times and wrong times, to use it. ‘It’s a bad workman who blames his tools’. I think if you use a good classifier appropriately, and the methods/results are audited by an experienced person, the combination of the two, each allowing for the other’s weaknesses, can work well.

Do you think that increased awareness of the other noises recorded during bat surveys has wider implications for conservation? For example, can you provide us with a situation where bat survey recordings might be useful for other species/purposes?

Definitely. This is one of the main threads within this work and the examples are numerous. We live in a country which, relatively speaking, isn’t that diverse when it comes to night-time species (bats, other mammals, birds, insects…). But even in the British Isles we have bush crickets, moths, birds, shrews, voles etc that can all be identified either audibly or from the analysis of bat detector recordings. Now take this approach into more diverse parts of the world. We haven’t really begun to scratch many of the surfaces, as far as I can tell. Even just looking at the UK, I don’t believe for one second that ‘Is That A Bat?’ is anywhere close to the total picture of what we may encounter acoustically during darkness. There is so much more to find out and this knowledge will almost certainly lead to better decision making and associated benefits for conservation.

Bat survey technology is constantly progressing, and there is a lot of recording equipment and analysis software on the market. It’s not surprising that it can be confusing for even the most experienced ecologist. What advice would you give to an aspiring bat worker who wants to gain experience and skill?

Listen and learn from lots of different experienced people. Take all of their thoughts and blend these with your own developing technical knowledge and experience. Understanding how bat echolocation works and how this links to behaviour is an essential foundation that should be in place before someone begins to attempt to identify bat calls to a species or group level.  For example, the answer is often as much to do with where a bat is (relative to surroundings), as it is to do with what a bat is.

Be wary of anyone who tells you they can identify every bat call, or that the system they use is always right. Don’t be afraid to just call it what you know it is (eg Myotis), as opposed to trying to always get it diagnostically to species level (eg it’s a whiskered bat). In any case, for some jobs you won’t need to know the precise species on every occasion. Why risk your credibility when there is no reason to do so. When you start appreciating the reasons why you can’t identify every bat, you are beginning to become an experienced and respected bat worker. People who don’t really understand this subject are afraid not to identify everything. People who really understand this subject know that everything can’t be identified (not at this stage anyway!).

What was the most interesting, bizarre or unexpected non-bat sound you came across during the research and writing of this book?

I think my favourite is the Long-Eared Owl juvenile call, when slowed down 10 times. This is something many bat workers do with bat calls in order to make them audible, and with an unusual recording it might be how you would first listen to it before realising that it’s not a bat. It still makes me smile, for no scientific reason whatsoever.  It just reminds me of ‘Casey Jones & The Cannonball Express’ (the whistle from his steam engine). I know some of your younger readers will need to Google ‘Casey Jones’.

Finally – a question we ask all our authors – what is next for you? Do you have plans for further books?

Yes, two others. But I am scared to say too much at the moment for a number of reasons, including that once you say out loud what you are doing, the pressure is then piled on to get it done. I am just recovering from this one! So, I need some time to carefully consider which of the two ideas comes next and how to marry up the huge amount of time it takes to produce a book with other commitments.

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Also by Neil Middleton:

Social Calls of the Bats of Britain and Ireland
#212405
Brings together the current state of knowledge of social calls relating to the bat species occurring within Britain and Ireland, with some additional examples from species represented elsewhere in Europe. Includes access to a downloadable library of calls to be used in conjunction with the book.

 

The Effective Ecologist
#226648
The Effective Ecologist shows you how to be more effective in your role, providing you with the skills and effective behaviours within the workplace that will enable your development as an ecologist. It explains what it means to be effective in the workplace and describes positive behaviours and how they can be adopted.

Handbook of the Mammals of the World, an interview with the series creators

The final volume in the Handbook of the Mammals of the World series will be published in October 2019.

The first volume was published over a decade ago and Volume 9: Bats completes this hugely important reference series to the mammals of the world.

 

We asked publishers Josep del Hoyo and Albert Martinez to share their thoughts about the conception, production and fruition of this and the earlier Handbook of the Birds of the World series.

1. What inspired you to embark on the Handbook of the Mammals of the World series?
JOSEP: Well, in this case, our inspiration was very clearly the series’ predecessor: the Handbook of the Birds of the World (HBW). When we started on the Handbook of the Mammals of the World (HMW), we had already published 12 volumes of HBW and the results were encouraging, both in terms of enthusiastic reviews and commercial success. So, we thought it would be worthwhile to try to produce a sort of “sister series” covering all the mammals of the world. We saw it as natural that there should be a Handbook to properly treat all the animals forming part of the same Class to which we, as humans, belong. We were aware that while the number of professionals dedicated to mammals were high, that the number of amateur people interested in the group would be much lower than the equivalent public in birdwatching, so the series would be commercially riskier. But we were convinced of the project’s importance for science and conservation, so we decided to look for some support to make it happen.
We were extremely fortunate to find this support in the form of two Chief Editors for the series that were essential for its success. On one hand, celebrated primatologist Russ Mittermeier joined the project, bringing his own knowledge to the series, as well as achieving important funding, most notably from Conservation International, to get the project off its feet. Russ also enlisted the involvement of IUCN, International Union for Conservation of Nature, further emphasising the importance of conservation in the series, and drawing from the expertise of many of the IUCN Species Survival Commission (SSC) Specialist Groups.
On the other hand, Don Wilson, at the time Chairman of the Department of Vertebrate Zoology and Curator of the Division of Mammals at the National Museum of Natural History of the Smithsonian Institution, generously volunteered his time and effort to help the project, and this continued throughout the series in many different facets. For example, Don’s help was especially useful for finding and contacting the specialists to author the chapters, as well as for providing a strong taxonomic base with his book Wilson & Reeder (2005), Mammal Species of the World. A Taxonomic and Geographic Reference (3rd ed).
We are very grateful to both Russ and Don, and to the other Chief Editors and external supporters who made the project possible.

2. Volume 1 was Carnivores, a very charismatic order of mammals; when this was published in 2009, did you already know how many volumes the series would contain, and in what order they would be published?

ALBERT: We proposed Carnivores as an exploratory volume to study the viability of the project as we felt that it could be one of the volumes with the greatest interest for the readers.
When the first volume was published and once it was proven that the series was viable, we agreed shortly after with the Chief Editors, Don Wilson and Russ Mittermeier, on the total number of volumes in the series—eight—and their order. In the first preparatory meetings it was quickly decided not to follow a strictly phylogenetic sequence, and so, for instance, walruses, seals, and sea lions were treated along with the rest of sea mammals and not in the Carnivores volume.
The most important departure from the original plan was the need to split rodents into two volumes: Volume 6 and Volumes 7, in order to maintain the level of detail that had characterised the previous volumes. This decision was made after direct consultation with HMW subscribers (of 1840 respondents, 92% favoured two volumes). So, the series was extended from eight to nine volumes.

3. Could you provide a rough idea about how much hard work goes into publishing a single volume in the series?
ALBERT: The work is immense and summary numbers for the series are impressive (c.8000 pages, 443 colour plates, 5300 photos, 6400 range maps, 10,000s of references), as is the number of the people involved: 312 authors of texts, 10 artists, and more than a thousand photographers from all over the World.
The editing process for a single volume lasts between one-and-half and two years, it begins with the commission of the different families to the authors of texts and the plates to the artists. The in-house editing phase has lasted about a year in the last volumes. The first three volumes appeared with a cadence of two years, but from HMW4 on we have managed to publish a volume per year without fail.

4. Is there a certain family or order of mammals you are particularly fascinated by?
ALBERT: It is difficult to choose, but maybe Carnivores, Hoofed Mammals, or Primates. Also Marsupials as they are really exotic and give us a very clear idea of the big conservation threats that face island species or species with reduced ranges. Looking at the distribution maps you become very aware of the high number of species with tiny distributions and those that only survive thanks to strict conservation measures.

5. What challenges did you face along the road to completion of this series?
ALBERT: During the 11 years of editing the HMW series (2009–2019) and with so many people involved, we have faced all kinds of difficulties with authors, artists, and editors (illnesses, accidents… and even Brexit at the end!). Especially complicated has been the instability in the taxonomy with habitual last-minute changes in the final stages of the editing process (e.g. new species described, rearrangements in the sequence of the species due to improvements in the knowledge of phylogenies, etc), which have forced us to completely redo already laid-out families many times. Despite such challenges, I want to highlight the impressive enthusiasm and dedication which all the participants have shown for this project.
It is very rewarding to see the commitment and effort that many experts have put into the project, having themselves seen in the HMW series an important achievement in their field of work. The selfless collaboration that we have received from a multitude of specialists not directly involved in the project has helped us in many ways, like providing material to allow the artists to draw rare species.

6. What do you hope will be the legacy of the Handbook of the Birds of the World and the Handbook of the Mammals of the World series?
JOSEP: Since we finished the HBW series some years ago (2013), we now have a better perspective on what this legacy may be. We have some indications that show that HBW, which covered all the birds of the world for the first time ever, represents a “before and after” in knowledge and interest in birds. It is true that before HBW there was a good deal of interest in birds in parts of the world like Europe, North America, Australia or South Africa, but in many other parts of the world, including in Tropical Regions with the richest biodiversity, there was a clear lack of even the most basic information. So we think the existence of the series has helped a bit to balance this situation, and has been an influence so that now many more people are interested not only in birds of their own country, region or local patch, but also at the global level, which we are convinced is good, eventually, for conservation.
With the HMW series, which we are just finishing now, we think similar effects will appear. While with birds the interest across the families was more or less regular, mammals have an added complication that some groups receive much more attention than others. So we think that the volumes dedicated to groups like rodents and, especially, the last one dedicated to bats, will be important for bringing together the knowledge that was much more disperse and less accessible, in a single, comprehensive treatment. This will also show where there are still gaps in the knowledge to encourage further study.

7. How do you feel about the imminent fruition of over ten years of publishing the Handbook of the Mammals of the World series – do you have any new projects in the pipeline that you can tell us about?
JOSEP: Well, we have several big projects that we are studying carefully, but we are also aware that the number of people interested in other groups of biodiversity is many times smaller than those interested in birds and even in mammals. But a number of good possibilities do exist, particularly if there is an awareness that such coverage gives a push to the knowledge and conservation of the group.

Meanwhile, we are still very busy with birds and mammals. For birds we published the HBW and BirdLife International Illustrated Checklist of the Birds of the World in two volumes and we are already working on the equivalent illustrated checklist for the mammals. Also, given the important patrimony we hold of the illustrations of all the birds of the world, we have started the Lynx and BirdLife International Field Guides Collection, which is producing good results, and we hope we can pursue a similar line with mammals. In this way, the two Handbook series can help us create field guides to countries for which they are none, thus, raising awareness and knowledge, which in turn can lead to greater local conservation.

HWM, Volume 9: Bats and the complete Volumes 1 to 9 are available at a special pre-publication price until the end of September

Handbook of the Mammals of the World, Volume 9: Bats
Oct 2019 *124.99 £144.99
The final volume in this monumental series profiles the world’s bat fauna.

*Pre-publication price applies to orders until 30th September 2019

 

Handbook of the Mammals of the World, Volumes 1 to 9
Oct 2019 *999.00 £1250.00
The whole set for under £1,000: this offer is available for a limited time only..

*Pre-publication price applies to orders until 30th September 2019

 

Browse all volumes in the Handbook of the Mammals of the World series

Browse all volumes in the Handbook of the Birds of the World series

 

NHBS Field Sessions: Waterway Surveys for Daubenton’s Bats

NHBS’ staff members are wild about wildlife! To showcase this, we are encouraging our team to write blogs about their experiences with nature.

During the Summer months, Jon Flynn, a member of NHBS’ Wildlife Equipment Team attended a number of Waterway Surveys for Daubenton’s bats (Myotis daubentonii). Read more about his survey experiences below:

Stretch of the River Teign captured by Westcountry Rivers Trust via Flickr (CC BY 2.0).
Stretch of the River Teign captured by Westcountry Rivers Trust via Flickr (CC BY 2.0).

“On Monday 6th July I took part in a Waterway Survey for Daubenton’s bat along a stretch of the River Teign in Devon. The survey is completed twice per year in conjunction with the Bat Conservation Trust and is part of an ongoing data collection programme for bat species around the UK. The lead for this particular survey was John Mitchell who has been surveying this particular length of the Teign, near Teigngrace, for a good number of years. It was my third survey there.

The survey was due to start 40 minutes after sunset, so we met at 9.00pm and made our way along the edge of a maize field to arrive at our first stopping point. This was to be a transect survey which meant walking a length of the river bank and stopping at ten predetermined points to record bat activity at each one. We stood at the river’s edge and immediately noticed that the river level was a lot lower than it was during our last visit a year or so ago. We recorded air temperature and cloud cover and, as we prepared, various species of bats could already be seen zooming around the trees and openings as they commenced another night of nocturnal foraging. The air was very warm, still and humid, and flying insects were everywhere including a host of moths and some less welcome biting species.

As the light faded it was time to start. With bat detectors switched on and earphones in place, we directed a torch beam on the river’s surface and awaited the arrival of the first Daubenton’s.

Looking for bats at twilight by Nic McPhee via Flickr (CC BY 2.0).
Looking for bats at twilight by Nic McPhee via Flickr (CC BY 2.0).

The Daubenton’s bat is a species which typically occupies riparian woodland.  They often roost in trees along the river bank and hunt by skimming low over the surface of the water for insects. They can take prey from the water’s surface using their feet or tail membrane.

As bats skimmed through the torch beam we were able to count them. We counted the number of passes that we observed and for this a clicker counter is always useful! The bats that we heard but did not see were also recorded as additional information. I set my Magenta 5 at 50hz and listened whilst John relied on his trusty and more accomplished Bat Box Duet.

After four minutes on the stopwatch we finished counting, compared counts and wrote down results. At stop number 1 there were certainly bats present, but they were swooping around quite high above the water surface and not showing the typical behaviour of Daubenton’s – John was dubious that they were our target species so we recorded them only as potential sightings.

Using GPS devices and torches we left for Survey Point 2 further down the river bank and repeated the same process as before. At this location there was no denying that these WERE Daubenton’s bats, as the torch beam caught their pale almost white ventral fur, confirming their identity. Our detectors were full of noise too, including the typical intense zap as a bat homed in on prey.

A close-up of a Daubenton's bat. Image captured by Gilles San Martin via Flickr (CC BY 2.0).
A close-up of a Daubenton’s bat. Image captured by Gilles San Martin via Flickr (CC BY 2.0).

On we progressed with eight more stopping points to go. Occasionally our river bank scrambles took us through thickets of invasive Himalayan balsam (Impatiens glanduliferaand Japanese knotweed (Fallopia japonica) a sobering reminder of how our countryside is changing. The night remained still and warm and it almost felt like we were in a different country.

After eight more stops my watch said 11:20pm. It was good to see that bats were in profusion that night, as John stated ‘It was one of the best ever totals, with one stopping point recording over 50 passes!‘.

Two weeks later and we repeated the process. But this second night felt noticeably cooler and there were fewer insects on the wing. Nevertheless bats were still out and about in reasonable numbers and an average score was calculated between the two Waterway surveys.  Overall there were encouraging signs that the Daubenton’s bat continues to do well along this particular stretch of the Teign.”

To find out more information about the various bat detectors available, go to our website. To find out more about how you can help bats in your local area, have a look at our handy guide.

If you like the idea of taking part in Waterway Surveys (or other kinds of bat surveys) then contact the Bat Conservation Trust or have a look at their website here. It’s great fun and you can put your bat detector to important use!

International Bat Weekend 2018

International Bat Weekend (formerly European Bat Night) has been celebrated since 1997 in 30 countries around the world. This two-day event is a fantastic chance for conservation groups and NGOs to raise the profile of bats and to educate the public about these fascinating, yet often misunderstood, nocturnal creatures. Events include presentations, exhibitions and bat walks which, in 2018, will be held over the weekend of the 25th-26th August.

An evening walk with a bat detector provides a great glimpse into the mysterious world of bats.

In the UK, events are organised by the Bat Conservation Trust and you can search for things happening near to you on the events section of their website. International events can be viewed on the Eurobats website.

The Bat Conservation Trust has also put together a helpful handout with lots of ideas for organising your own bat-related event. Perhaps you could even raise some money for the Trust to help them to continue the valuable work that they carry out to help bats in the UK. If you decide to hold an event, don’t forget to let them know so they can feature it on their website!

You might also like to check out our handy guide to find out more about how you can help your local bats.

Top 10 Bat Boxes for New Builds and Developments

Schwegler 1WI Bat BoxLooking for a bat box but don’t know which one to buy? This article is the third in a three part series designed to help you to make the right choice. Here you will find our top 10 boxes for incorporating into the masonry of a new build or development. The previous two posts feature the best boxes for trees and woodland and for walls and fences.

For each box listed you will also find helpful information such as its dimensions and weight and the box type (e.g. whether it is for summer use, for hibernation or for access into an existing roost space).

The Glossary below provides a guide to the key terms used in the descriptions.

• Woodcrete/WoodStone: A blend of wood, concrete and clay which is very durable. It is also breathable and helps to maintain a stable temperature inside the box.
• Summer: Summer boxes are suitable for the warmer months but are less likely to be used over the winter.
• Hibernation: Designed to be larger and better insulated, hibernation boxes will provide a safe and warm space for bats over the winter.
• Maternity: Suitable for the formation of colonies and raising of young.
• Access: Provides an entrance to an existing roof space such as a wall cavity or loft.
• Crevice: Provides one or more narrow roost spaces. Species which prefer this type of box include common, soprano and Nathusius pipistrelle, Brandt’s and whiskered bats.
• Cavity: Provides a more spacious roost space. Bats such as brown long-eared, Daubenton’s and Natterer’s bats prefer cavity boxes.
• Large cavity: These boxes allow space for flight within the roost which is preferred by brown long-eared bats in particular.


Schwegler 1FR Bat Tube1. Schwegler 1FR Bat Tube

• Made from: Woodcrete
• Dimensions: 47.5 x 20 x 12.5cm; 9.8kg
• Box type: Cavity, summer

 

Habibat Bat Box2. Habibat Bat Box

• Made from: Concrete and brick
• Dimensions: 44 x 21.5 x 10.2cm; 9kg
• Box type: Crevice, summer

 

3. Bat Block

• Made from: Concrete and FSC wooden panel
• Dimensions: 21.5 x 44 x 16cm; 15kg
• Box type: Crevice, summer, maternity (south or west facing), hibernation (north facing)

 

 

Schwegler 1FE Bat Access Panel4. Schwegler 1FE Bat Access Panel

• Made from: Woodcrete
• Dimensions: 30 x 30 x 8cm; 5.1kg
• Box type: Large cavity, access

 

Bat Access Tile Set5. Bat Access Tile Set

• Made from: Clay
• Dimensions: 25.5 x 16cm; 3.5kg
• Box type: Cavity/crevice, access

 

Bat Brick6. Bat Brick

• Made from: Brick
• Dimensions: 6 x 21.5 x 10cm; 1.9kg
• Box type: Cavity, access

Build-in WoodStone Bat Box7. Build-in WoodStone Bat Box

• Made from: WoodStone
• Dimensions: 50 x 21 x 16cm; 9.5kg
• Box type: Crevice, summer

 

Schwegler 1WI Bat Box8. Schwegler 1WI Bat Box

• Made from: Woodcrete
• Dimensions: 54.5 x 34.5 x 9.5cm; 15kg
• Box type: Crevice, hibernation and maternity

 

Ibstock Enclosed Bat Box C9. Ibstock Enclosed Bat Box C: Small

• Made from: Concrete and brick
• Dimensions: 21.5 x 21.5 x 10.5cm; 6.7kg
• Box type: Crevice, summer

 

Habibat Bat Access Slate10. Habibat Bat Access Slate

• Made from: Slate
• Dimensions: 41.8 x 37.5 x 8cm; 1.3kg
• Box type: Large cavity, access

Browse our full range of build-in bat boxes.


The full range of nest boxes can be found in our online shop, as well as a useful nest box price list which can be downloaded as a pdf.

Top 10 Bat Boxes for Walls and Fences

Improved Cavity Bat BoxLooking for a bat box but don’t know which one to buy? This article is the second in a three part series designed to help you to make the right choice.

Here you will find our top 10 boxes for installing on an external wall or fence. The first and third posts cover the best options for installing on a tree in a garden, park or woodland and for building into a new build or development respectively.

For each box you will also find helpful information such as its dimensions and weight and the box type (e.g. whether it is for summer use, for hibernation or for access into an existing roost space).

The Glossary below provides a guide to the key terms used in the descriptions.

• Woodcrete/WoodStone: A blend of wood, concrete and clay which is very durable. It is also breathable and helps to maintain a stable temperature inside the box.
• Summer: Summer boxes are suitable for the warmer months but are less likely to be used over the winter.
• Hibernation: Designed to be larger and better insulated, hibernation boxes will provide a safe and warm space for bats over the winter.
• Maternity: Suitable for the formation of colonies and raising of young.
• Access: Provides an entrance to an existing roof space such as a wall cavity or loft.
• Crevice: Provides one or more narrow roost spaces. Species which prefer this type of box include common, soprano and Nathusius pipistrelle, Brandt’s and whiskered bats.
• Cavity: Provides a more spacious roost space. Bats such as brown long-eared, Daubenton’s and Natterer’s bats prefer cavity boxes.
• Large cavity: These boxes allow space for flight within the roost which is preferred by brown long-eared bats in particular.


Schwegler 1FF Bat Box1. Schwegler 1FF Bat Box

• Made from: Woodcrete and wood
• Dimensions: 43 x 27 x 14cm; 9.5kg
• Box type: Cavity; summer, maternity

 

2. Vivara Pro WoodStone Bat Box

• Made from: WoodStone
• Dimensions: 25 x 19 x 16.5cm; 4.5kg
• Box type: Cavity; summer

 

Schwegler 2FE Bat Shelter3. Schwegler 2FE Wall-Mounted Bat Shelter

• Made from: Woodcrete
• Dimensions: 30 x 25 x 5cm; 2.5kg
• Box type: Cavity, hibernation

 

Chavenage Bat Box4. Chavenage Bat Box

• Made from: FSC Wood
• Dimensions: 38 x 18 x 10cm; 1.2kg
• Box type: Cavity, summer

 

Schwegler 1WQ Bat Roost5. Schwegler 1WQ Summer & Winter Bat Roost

• Made from: Woodcrete
• Dimensions: 58 x 38 x 12cm; 22kg
• Box type: Crevice, hibernation and maternity

 

Improved Cavity Bat Box6. Improved Cavity Bat Box

• Made from: FSC Plywood
• Dimensions: 38 x 24 x 15cm; 1.5kg
• Box type: Cavity, summer

 

7. Large Multi Chamber WoodStone Bat Box

• Made from: WoodStone and wood
• Dimensions: 27.5 x 15 x 16cm; 4kg
• Box type: Crevice, summer, maternity, hibernation (mild winters)

 

Beaumaris WoodStone Bat Box8. Beaumaris WoodStone Bat Box: Midi

• Made from: WoodStone
• Dimensions: 39 x 29 x 6cm; 4.4kg
• Box type: Crevice, summer

 

Improved Roost Maternity Bat Box9. Improved Roost Maternity Bat Box

• Made from: FSC Plywood
• Dimensions: 49 x 26 x 13cm; 6.6kg
• Box type: Crevice, maternity

 

Low Profile WoodStone Bat Box10. Low Profile WoodStone Bat Box

• Made from: WoodStone
• Dimensions: 44 x 29 x 9cm; 4.7kg
• Box type: Crevice, summer

 

Browse our full range of bat boxes for external walls.

Top 10 Bat Boxes for Trees and Woodland

Schwegler 2F Bat Box front panel with one of its residents.

Looking for a bat box but don’t know which one to buy? This article is the first in a three part series designed to help you to make the right choice.

The following two blog posts will cover our bestselling boxes for walls and fences and for building into a new build or development.

Here you will find our top 10 boxes for installing on a tree, in a garden, park or woodland. For each box you will also find helpful information such as its dimensions and weight and the box type (e.g. whether it is for summer use, for hibernation or for access into an existing roost space).

The Glossary below provides a guide to the key terms used in the descriptions.

• Woodcrete/WoodStone: A blend of wood, concrete and clay which is very durable. It is also breathable and helps to maintain a stable temperature inside the box.
• Summer: Summer boxes are suitable for the warmer months but are less likely to be used over the winter.
• Hibernation: Designed to be larger and better insulated, hibernation boxes will provide a safe and warm space for bats over the winter.
• Maternity: Suitable for the formation of colonies and raising of young.
• Access: Provides an entrance to an existing roof space such as a wall cavity or loft.
• Crevice: Provides one or more narrow roost spaces. Species which prefer this type of box include common, soprano and Nathusius pipistrelle, Brandt’s and whiskered bats.
• Cavity: Provides a more spacious roost space. Bats such as brown long-eared, Daubenton’s and Natterer’s bats prefer cavity boxes.
• Large cavity: These boxes allow space for flight within the roost which is preferred by brown long-eared bats in particular.


1. 2F Schwegler Bat Box

• Made from: Woodcrete
• Dimensions: 33 x 16 x 16cm; 4kg
• Box type: Cavity, summer

 

2. 2FN Schwegler Bat Box

• Made from: Woodcrete
• Dimensions: 36 x 16 x 16cm; 4.3kg
• Box type: Cavity, summer

 

3. Improved Crevice Bat Box (Double Crevice)

• Made from: FSC Plywood
• Dimensions: 33 x 16 x 10cm; 1.4kg
• Box type: Crevice, summer

 

4. Eco Kent Bat Box

• Made from: Recycled plastic, FSC wood
• Dimensions: 52 x 23 x 16cm; 4.5kg
• Box type: Crevice, summer

 

5. Chavenage Bat Box

• Made from: FSC Wood
• Dimensions: 38 x 18 x 10cm; 1.2kg
• Box type: Cavity, summer

 

6. 1FS Schwegler Large Colony Bat Box

• Made from: Woodcrete
• Dimensions: 44 x 38 x 38cm; 10kg
• Box type: Large cavity, hibernation and maternity

 

7. Double Chamber Bat Box

• Made from: FSC Wood
• Dimensions: 28 x 16 x 16cm; 1.6kg
• Box type: Crevice, summer

 

8. Vivara Pro WoodStone Bat Box

• Made from: WoodStone
• Dimensions: 25 x 19 x 16.5cm; 4.5kg
• Box type: Cavity, summer

 

9. Improved Cavity Bat Box

• Made from: FSC Plywood
• Dimensions: 38 x 24 x 15cm; 1.5kg
• Box type: Cavity, summer

 

10. Schwegler 1FW Bat Hibernation Box

• Made from: Woodcrete
• Dimensions: 50 x 38 x 38cm; 28kg
• Box type: Cavity, hibernation and maternity

 

Browse our full range of bat boxes for trees and woodland.


The full range of NHBS bat boxes can be found in our online shop, as well as a useful nest box price list which can be downloaded as a pdf.

 

Kaleidoscope 4.3.0 Bioacoustic Software Now Available

The newest version of Kaleidoscope, version 4.3.0, is now available to download from the Wildlife Acoustics website.

See below for details about the new features included in this release, as well as a handy table to see which version of Kaleidoscope is right for you, and some useful tutorial videos.

New features include:

New Bat Auto-ID Classifiers
New bat classifiers for North America, Neotropics, Europe and South Africa as well as updated common names for some species. The default setting for classifiers is now “Balanced” which is a useful compromise between the more sensitive and more accurate options.

New time-saving workflow features
New features in the results viewer window include:
• When opening a saved results spreadsheet, a file browser allows you to easily locate the folder containing the corresponding input files
• Bulk ID multiple selected rows
• Bulk copy files in selected rows to a specified folder

Full support for GUANO metadata (Kaleidoscope Pro only)
Kaleidoscope now reads and write GUANO information alongside Wildlife Acoustics metadata (WAMD).  This will been shown in the file at the end of the metadata notes window.

Bug fixes
Several bugs have also been fixed in the new release, details of which can be found in the Kaleidoscope documentation.

Which version of Kaleidoscope is right for me?

Kaleidscope Tutorial Videos


Kaleidoscope UK, Kaleidoscope Neotropics and Kaleidoscope Pro are all available to purchase from NHBS.

 

New Bat Detectors for Spring 2017

It’s that time of year again. Spring has sprung earlier than ever, and the survey season will very soon be under way. In this post we look at some of the fantastic new bat detectors due for release this spring.

Anabat Swift

The Anabat Swift from Titley Scientific is based on the excellent design of the Anabat Express and records in full spectrum as well as zero crossing. Users can choose between sample rates of 320 or 500kHz and a built-in GPS receiver automatically sets the clock, calculates sunrise and sunset times and records the location of the device.

 

Echo Meter Touch 2

The Echo Meter Touch 2 is perfect for bat enthusiasts and students and will let you record, listen to and identify bat calls in real-time on your iPad, iPhone or iPod Touch. All you need is your iOS device, your Echo Meter Touch 2 and the Echo Meter Touch App which is a free download from the iTunes store.

Echo Meter Touch 2 Pro

Designed for consultants and professional bat workers, the Echo Meter Touch 2 Pro has all the great features of the Echo Meter Touch 2 but with additional user options such as an adjustable sample rate (256kHz and 384kHz), adjustable gain and advanced trigger settings.

Batcorder Mini

The compact Batcorder Mini has a very simple user interface with just a single button to start and stop recording. Calls are recorded in full spectrum onto the built-in memory (64GB) and the internal lithium-ion battery is chargeable by USB. A built-in GPS receiver sets the time, date and location.

Ultramic384 Ultrasound Microphone

This high performance ultrasound microphone will connect to a USB port for real time listening and can also be used as a stand-alone recorder when used with a USB battery. An internal microSD card slot allows data to be recorded.

Batcorder GSM

The Batcorder GSM is designed for use at a wind turbine site and includes a microphone disk which is inserted directly into the turbine nacelle. The unit runs off mains power from the turbine and a GSM function lets you receive status messages, reassuring you that everything is recording correctly. A Raspberry Pi setup also lets you backup your files to a memory drive and download data directly or over an internet connection.

 

 

Our full range of bat detectors can be found at www.nhbs.com