The Acoustic Identification of Small Mammals

Yellow-necked mouse by John Harding.

As static bat detectors have become more widely used, there are now many thousands of hours’ worth of nocturnal recordings captured each year from a vast spread of locations. This level of coverage has not only improved our ability to monitor bat populations, but also offers the potential to gather information on other animals that communicate at the same ultrasonic frequencies as bats. The calls of bush-crickets, for example, are commonly picked up as ‘by-catch’ during bat surveys, which has allowed the development of software that automatically recognises any cricket calls in a recording and assigns them to individual species.

In the December issue of British Wildlife, Stuart Newson, Neil Middleton and Huma Pearce explore the previously untapped potential of acoustics for the survey of small terrestrial mammals – rats, mice, voles, dormice and shrews. Small mammals use their calls for a variety of purposes, including courtship, aggressive encounters with rivals and communication between parents and their offspring. To the human ear, the high-pitched squeaks of different species sound much alike, but closer examination reveals them to be highly complex, extending beyond the range of our hearing into the ultrasonic and showing great variation in structure.

Mammal terrariums used for holding individuals overnight in the recording ‘studio’.

But is it possible to distinguish the calls of different species? To answer this question, the authors began the time-consuming task of building a call library by taking recordings of all Britain’s native (and some non-native) small mammals. Call-analysis software was then used to examine the recordings and look for consistent differences between species, with some fascinating results – the calls of shrews, for example, can be readily separated from those of rodents by their warbling/twittering quality, while the house mouse typically calls at a higher frequency than any other species. Remarkably, it appears overall that the vocalisations of most species have their own diagnostic features, and that, with care, it should be possible to identify a high proportion of calls to species level.

Recorded calls of (a) Brown & (b) Black Rats

Small mammals are unobtrusive and hard to observe, which means that even the more familiar species, such as the Brown Rat, are severely under-recorded. The ability to detect and identify small mammals by their calls therefore offers great potential to help fill gaps in our knowledge of the distribution and abundance of British species. Analysis of calls collected by static detectors – whether specifically set to target small mammals or deployed as part of a bat survey – could in future offer a rich source of data and help to complement traditional methods, such as the use of Longworth traps or footprint tunnels.

To read about the key identification features of small-mammal calls, see the December issue of British Wildlife (more information can be found on the British Wildlife website) and to accompany this article, audio clips of the species discussed are available to download here. This work will contribute to the BTO Acoustic Pipeline, which allows the upload of sound recordings and automatically detects and identifies any calls of bats, bush-crickets and small mammals. For more information about the project, see the BTO Acoustic Pipeline webpage and read comments from the authors here.


Bat detectors for small mammal survey:

Passive bat detectors are designed to be left in the field for unattended monitoring and are the ideal choice for ecologists and researchers wishing to monitor local bat populations. For similar reasons, they are also a good choice for recording small mammals as they record all frequencies continuously and retain complex details of the call structure, allowing the sounds to be analysed later using bioacoustics software. Detectors such as the Song Meter Mini, Anabat Swift and Elekon Batlogger A+ all features excellent weatherproofing, long battery life and the ability to programme recording schedules.

Song Meter Mini
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Anabat Swift
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Elekon Batlogger A+
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Recommended reading:

Is That a Bat?
#245066

An essential and unique guide to interpreting and recognising non-bat sounds and noises picked up by your bat detector.

CIEEM Autumn Conference 2020: Time to Change

CIEEM’s “Time to Change: Putting the Environment at the Heart of Social and Economic Wellbeing” conference was accessed remotely, like so many of our gatherings this year. The virtual platform was used with great ease, allowing many people to access the talks which seamlessly focused on the various key speakers. The day also included live Q&As and breakout rooms, with all sessions ending in lively panel discussions. The conference took place over three days and focused on six different sub-topics. The general theme was ‘The Future’; how best to arm ourselves and the importance of collaboration, including people from all sectors and the general public.

At NHBS, we were particularly interested in the ‘New Tools and Technology Advancing Professional Practice’ session that was held on the final afternoon. This session covered Artificial Intelligence (AI), remote sensing and soundscape ecology, and explored the best methods of using the information that these technologies provide us with. 

Tom August (UK Centre of Ecology and Hydrology) took us through how AI can learn when being used for species identification. It can also be a great tool for involving the public in research and an aid to improving our own identification skills. He discussed how we can help encourage technology learning by making positively identified photographs attached to species ecology widely available. He also assured us that AI is continually learning and improving: for example in 2014 AI could identify species to the same level as an average skilled person, whereas by 2017 it could function to just below the level of a species expert. 

Jonny Miller and Joshua Aves (WSP) then took us through a working example of using drones and camera footage alongside GIS to improve survey and analysis efficiency (in this example up 70%). They explained that this can be great for creating baseline information and can help with safety when surveying more dangerous areas such as roadsides. They anticipate that the use of this technology will increase due to new needs to demonstrate biodiversity net gain. 

Oliver Metcalf (Manchester Metropolitan University) demonstrated the use of audio recording devices to survey for various species and the benefits thereof. These benefits included removal of the surveyor effect on the target species’ behaviour as well as being able to analyse the same recording multiple times, in different ways and by different people – this helps to reduce error and increase the number of target species. When used in areas with reduced sight it can also be more productive than traditional visual surveys. His talk covered the drawbacks of the method, for example, there is no rule book around this technology, and if there is a loss of data then it is a big loss. At the moment, the technology is biased towards birds, and although large amounts of data are produced (which in itself has its benefits and challenges) there is not yet a wide database for all species. However, automated functions such as species identification and identifying false positives are continually improving. Oliver went on to explain that the use of acoustic indices does not  require a high level of skill and has a huge variety of applications such as habitat type prediction (which maps well onto wilderness perception), variation in sound bar correlating to species richness, and detection of temporal trends.

As the use of all of these technologies result in large databases, Gregory Slack and Matthew Whittle (Jacobs UK Ltd) took us through a working example of how much data to collect at a site survey for bats and how to analyse it. They explained that there is a need to collect data with deeper analysis reporting more than means and medians (and believe this will be reflected in new guidelines) but that with use of acoustic recorders and statistical software such as R, minimal added survey effort does not add much when it comes to analysis, as this can be automated. Analysis like this can also be used throughout the study rather than only at the end. 

The overarching takeaway from this session was that we should embrace the use of new technologies and that we all have a part to play in helping to develop them. There were discussions as to whether these new technologies would replace us (ecologists) but all speakers were reassuring that they would only make our lives easier. There was emphasis that their use should be carried out by (or at least alongside) ecologically trained professionals to provide meaningful data. 

All of the talks from this inspiring session left me excited for the beneficial impacts of new technology.

Buglife Q&A with Paul Hetherington

Buglife is the only organisation in Europe devoted to the conservation of all invertebrates. Invertebrates are currently facing an extinction crisis.
Today, thousands of invertebrate species are declining and many are heading towards extinction. Worldwide 150,000 species could be gone by 2050 if we do nothing. We spoke to Paul Hetherington at Buglife about the work they are doing to stop the extinction of invertebrates.

Can you tell us a little bit about the history of Buglife and what you consider to be your main goals?

The conservation movement grew during the 1990s, but there was no organisation specialising in invertebrates. This was brought sharply into focus by the creation of the UK Biodiversity Action Plan in 1994, when no organisation existed to fly the flag for invertebrates – to make sure their conservation needs were being looked after. A Feasibility Committee was established to look at the details of setting up an invertebrate conservation body, and ‘A Statement of Need for a New Organisation’ was produced. Twenty of the leading conservation organisations (including the RSPB and Wildlife Trusts) acknowledged that the conservation movement lacked a major spokesman for invertebrate conservation, and welcomed the establishment of one. The result was the foundation of Buglife in 2000, the only organisation in Europe devoted to the conservation of all invertebrates.

Buglife’s aim is to halt the extinction of invertebrate species and to achieve sustainable populations of invertebrates.

We are working hard to achieve this through:

– Promoting the environmental importance of invertebrates and raising awareness about the challenges to their survival.

– Assisting in the development of legislation and policy that will ensure the conservation of invertebrates.

– Developing and disseminating knowledge about how to conserve invertebrates.

– Encouraging and supporting invertebrate conservation initiatives by other organisations in the UK, Europe and worldwide.

– Undertaking practical conservation projects that will contribute to achieving our aim.

Woodland bulb planting event

In an ideal world where funding for conservation was limitless, what would be your top priorities for ensuring the survival of invertebrates and rectifying the damage that has been done to their populations and habitats?

Putting connectivity back into the landscape. Invertebrates are suffering from a plethora of issues: habitat loss, pesticides and herbicides, climate change, isolation of habitat. Connecting up the remaining good habitat is the single most important change for invertebrates as they can escape natural or human made disaster where they live and can migrate to avoid extreme climate change. This is the principle behind Buglife’s B-Lines project that has plotted a route for connectivity between the best remaining invertebrate habitats across the UK.

B-Lines mapping


On your website you feature the famous quote by David Attenborough that concludes with the terrifying line: “…if the invertebrates were to disappear, the world’s ecosystems would collapse.” Do you think that in general we still place too much emphasis on saving what is often referred to as the ‘charismatic megafauna’ and do not value the smaller animals and plants that are the backbone and life support of our world?

A look at how money is invested in saving species reveals that larger mammals are by far the biggest beneficiaries at over £60 per species whilst invertebrates the worst funded at under 6 pence per species. A sad reflection on how humans fail to understand that if we don’t look after the small creatures the big ones will disappear too, bottom-up conservation has far more likelihood of long term sustainability. Yes, tigers and similar have cute cuddly eyes but without invertebrates the food chains that they depend on would collapse and with them the megafauna would go too. Too often we take the invertebrates for granted as something that is just there, small and ‘insignificant’ forgetting that in reality they are small but irreplaceable foundations for the whole web of life that supports the megafauna and people too.

2020 has been an extremely challenging year for most individuals and organisations. How has the pandemic affected Buglife and the work that you are doing?

The Covid pandemic has had a massive impact upon all of us and Buglife have had to be extremely careful with project organisation and financial controls, to ensure that vital conservation work has been delivered safely and that our staff resource has been retained in gainful employment. Ways of working have changed with the closure of offices and a shift to home working for all made possible through recent investment in new IT systems. Most engagement activities have shifted from face to face to online platforms as have meetings to influence policy and media. Some of these enforced changes are likely to have a long term beneficial outcome in reducing our organisational carbon footprint and finding new ways of delivering training and engagement that can reach larger audiences. A few of the impacts have meant works being delayed a year such as surveys for specific invertebrates that are only around for short periods. It should also be recognised that new ways of working can place extra burden on staffing resources as meetings flow on without breaks so we have also looked to bring in external supports for staff when needed. The biggest negative impact has been the closure of most project funders to new applications over the pandemic, making it impossible to establish all the new projects hoped for in 2021.


What would you consider to be your greatest success as a charity?

This is a really tough question as over the last 20 years Buglife has achieved  saving many sites for invertebrates from developments, banning extremely harmful chemicals, persuading governments to adopt pollinator strategies, but for sheer scale, B-Lines mapping completed across the entire UK has got to be the number one achievement, as there is now a route map for future interventions to ensure the long term survival of the small things that run the planet.

Finally, for anyone inspired to get involved in invertebrate conservation, how would you recommend that they do this?

Practical experience of conservation work is as important as qualifications, a sound knowledge of a few groups of invertebrates is a great extra to have but equally important is experience of public engagement, volunteer leadership and above all else an ability to multitask.


You can find out more about Buglife and the work they do from their website and by following them on Facebook and on Twitter

NHBS In the Field – Mammal Footprint Tunnel

Footprint tunnels are a useful, cost-effective, non-invasive tool for presence/absence surveying of small mammals. Food left in the centre of the tunnel encourages passing animals to walk over the ink pads, leaving their footprints on the tracking paper. With the use of a guide, the mammal in question can then be identified from the footprints left behind.

There are a number of benefits of using footprint tunnels. As they are non-invasive, the tunnel can be set up and left without fear of harming animals and are a good way to assess a site prior to in-depth species studies. They are also quick to check compared to other methods. For example, although camera traps are also useful for presence/absence studies, it can be time consuming to sift through captured images and videos.

As is useful for any piece of equipment, footprint tunnels (and their replacement materials) are very light (55g), and so are easy to take out into the field. However, as they are quite long (119.5cm) they can be cumbersome to transport. Despite this, transportation is made easier due to their ability to be flat packed – their plastic construction allows for them to be folded easily.

The NHBS Mammal Footprint Tunnel comes flat packed with helpful assembly instructions. When assembled, the tunnel is wide enough to fit a full sheet of A4, saving you the trouble of cutting paper to size to use in the tunnel, and is large enough to allow access to animals such as hedgehogs but not larger mammals, such as foxes or badgers.

In addition to the kit you will need eight paperclips per trap, masking tape, some vegetable oil to mix with the included charcoal to make the ink, and some bait (chopped unsalted peanuts or dog/cat food is recommended).

Our work building is situated alongside the river Dart, only separated from the riverbank by a small wall and we wanted to find out what mammal species we have in the vicinity of our building. So we field tested a single NHBS Mammal Footprint Tunnel and here we share what we found and our thoughts on the tunnel.


How We Tested

The above image shows the kit contents: to the left is the tracking plate and on the right is the flattened prism that forms the tunnel. In the top right corner are the pins that secure the tunnel to the ground, charcoal, paper and masking tape (please note, paper, masking tape and vegetable oil are not included in the kit).

To set up the tracking plate, a sheet of A4 paper is placed at each end and secured with tape (ordinarily the paper would be secured with paper clips as is suggested in the instructions). Then we put several strips of masking tape across the centre of the tracking plate to create a large area of tape. The ink (a mixture of charcoal and oil) was painted on the two grey strips across the centre and bait was placed in the central area between the two ink pads.

Pictured is the tracking plate with the paper and masking tape attached.

We first set up the trap next to a bird feeding station – we already knew that the feeder is visited by voles and squirrels, and so would be an ideal place for us to put the footprint tunnel to the test! Although the feeder is raised, we opted to put the tunnel on the floor so that it was accessible to small mammals. As the tunnel was not placed on soft ground, bricks were used to secure the tunnel in place rather than the metal pins included in the kit. For bait we used bird seed as this is what the animals are used to eating at this particular location. The trap was left here for one (wet) night.

The first location that the tunnel was set was next to a bird feeder known to be visited by squirrels and voles.
The first tunnel set up, secured by bricks.

The second set up was just outside of our office alongside the wall that bordered the river. We hoped that this area would be patrolled by a number of small mammals, particularly hedgehogs as they have been seen here before. We baited the tunnel with cat food and the trap was left for three nights over the weekend – being outside office hours, we hoped disturbance would be minimal during this time.

The second placement of the tunnel


What We Found

The inner tracking plate was slightly fiddly to insert into the assembled prism tunnel, and we found that it was much easier to assemble the (pre-bent) prism round the tracking plate rather than sliding the tracking plate in. We used masking tape to secure the paper rather than paper clips as is suggested; this was beneficial when trying to get the tracking plate inside the tunnel as it was more secure than using paper clips.

In order for the bait to stay in place in the centre of the tracking plate the bait needed to be inserted after the tunnel was assembled. And so, because of the length of the tunnel, placing the bait into the tunnel was a little awkward. We found using a trowel to insert the bait made access easier, especially when trying not to disturb the ink.

In the first set up we were pleased to see that a vole had visited our tunnel and that the recording paper had stayed relatively dry despite the very wet weather. Sadly for our second attempt our bait of cat food was eaten by a cat!

Vole footprint tracks from first sighting. The photo is taken to scale of an A4 paper (the page filled the photo).

 

Cat footprints from second set up.

 

Cat tracks within tunnel.

 


Our Opinion

The Mammal Footprint Tunnel is an easy-to-use, lightweight monitoring device and a great tool for many small mammal presence/absence studies. Due to its simplicity and low cost, it is ideal for students or for those involved in public engagement.

Despite its light weight, its size makes it a bit of an awkward shape to carry, both when assembled and when flat packed. However, its ability to be flat packed allows for multiple tunnels to be transported without any additional difficulties. Placing ink on the outer edges of the paper may result in more footprints- in our experience something seemed to enjoy munching on the paper before getting to the actual bait. Getting the ink to the right consistency takes some trial and error, but we would recommend using less oil to achieve a thicker ink so that any footprints left behind are as dark as possible so that they are easier to identify.

The pins were sufficient in securing the tunnel and saved it from being blown away by the wind, but a medium-sized mammal (a cat in our case!) could move the trap when secured in soft soil, so this is something to bear in mind when situating your trap.

Overall this is a very easy-to-use, affordable tool and we would highly recommend it as an effective presence/absence surveying method for small mammals.


The Mammal Footprint Tunnel is available through the NHBS website.

To view our full range of mammal surveying equipment, visit nhbs.com. 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.

 

Amphibian and Reptile Conservation Trust Friends’ Day 2020

British Wildlife’s Assistant Editor Catherine Mitson joins the supporters of the Amphibian and Reptile Conservation Trust (ARC) for their annual Friends’ Day. With exclusive site visits and Q&A sessions on the agenda, this year’s Friends’ Day was set to be a great event. Here, Catherine shares with us some of the highlights.

Thankfully, with the existence of Zoom, the ARC Friends’ Day 2020 could go ahead, albeit not its usual format. The Amphibian and Reptile Conservation Trust planned a jam-packed Saturday afternoon to give their supporters the opportunity to see what ARC has been up to and to learn more about Britain’s native reptile and amphibian species.

Woolmer Forest is one of the most extensive and diverse lowland heathlands in Hampshire and home to 12 out of our 13 native reptile and amphibian species, including the rare Smooth Snake and Sand Lizard. Excitingly Blackmoor Heath, a 20ha site in Woolmer Forest, has become ARC’s newest nature reserve after a year-long fundraising appeal. Once introduced to the ARC team (most of whom were sporting fun animal-themed virtual backgrounds) the first video began, and we were taken on a virtual tour of the new reserve.

A priority at Blackmoor Heath is to reintroduce the Natterjack Toad, extending its range in Hampshire. Reducing tree cover and creating ponds are a few examples of the work being undertaken here to support a reintroduced population of Natterjacks. Not only is this vital management for Natterjacks and many other heathland species, this has also led to the exposure of bronze age barrows, or burial mounds – Blackmoor Heath is not only important for wildlife, but historically too.

Blackmoor – by the Amphibian and Reptile Conservation Trust

Next, Field Officers Ralph and Bryony took us to Crooksbury Common in Surrey, an important breeding site for Natterjack Toads. Bordered by a pine plantation, one of the major tasks here is to prevent the encroachment of pine trees, which if left unmanaged, would soon smother valuable heathland habitat. In the hope to restore good numbers of Natterjack Toads, the ARC team are also busy creating and maintaining large shallow ponds, critical for Natterjack breeding and egg-laying, as well as providing shelter for Natterjack adults during the cold winter months. We were also shown key Natterjack identification features, such as the distinctive yellow stripe that runs down the middle of their back.

Natterjack – by Chris Dresh

Moving away from heathlands, we suddenly found ourselves on the dunes of Aberdovey, Wales to discover all about the Connecting the Dragons project. ARC staff and volunteers have been working hard to create exposed sand patches on the dunes here (socially distanced of course) to provide the reintroduced population of Sand Lizards with basking spots and egg-laying sites, as well as making next year’s surveying much easier!

Perhaps not common knowledge to many, there are actually two races of Sand Lizard: the Northern dune race and the Southern heathland race. The morphological differences between the two races were described, highlighting the distinctive identification features. For instance, the males of the Northern dune race tend to be much lighter when they first emerge from hibernation compared to those of the Southern heathland race.  

Image by the Amphibian and Reptile Conservation Trust

The final site visit video took us to Dorset. Designated as a Special Area for Conservation and a SSSI, Great Ovens, an ARC nature reserve in Wareham Forest since 1996, is a truly special site. Similarly to Crooksbury Common, a surrounding pine plantation and the threat of scrub invasion means that a sensitive management programme is necessary to maintain the important mix of wet and dry heathland. This is not only beneficial for the amphibians and reptiles on the site, including Adders, Smooth Snakes and Sand Lizards, but also for other species such as Dartford Warbler, Silver-studded Blue, and Scarce Chaser. This was a common theme – habitat management for reptiles and amphibians will have a positive knock-on effect for other species, particularly in declining heathland habitats.

Dartford Warbler – by Guy Freeman
Great Ovens – by the Amphibian and Reptile Conservation Trust

Finally, Public Engagement Officer Owain took us out to find the rare Smooth Snake. Owain was successful in his search, and was able to show us a male Smooth Snake curled up safely underneath refugia (note that a license is required to monitor or handle this species). Owain went on to describe ARC’s ambitious four-year long Snake in the Heather project. Working in partnership with landowners, site managers and wildlife conservation charities, Snakes in the Heather endeavours to conserve the Smooth Snake across its range in southern England, as well as the lowland heathland habitat on which it, and many other species, depends.

Smooth Snake – by Chris Dresh

Throughout the Friends’ Day there were many opportunities for questions during the Q&A panel sessions; we learnt even more about ongoing ARC projects, the management of ARC’s nature reserves and the ecology of UK reptile and amphibian species. Many of the attendees were keen to know what they could do to help Britain’s reptiles and amphibian species and the ARC team enthusiastically provided us with information on how to get involved.

The ARC team – by Catherine Mitson

If you’re interested in becoming an ARC volunteer, or would like to become an ARC Friend to support their fantastic conservation work, you can find out more on their website.

Wild Nature Press: Publisher of the Month for November

Wild Nature Press are a UK-based natural history publisher specialising in books about marine life.

This winter will see the arrival of several exciting new additions to their range; beginning with Field Guide to Sharks, Rays and Chimaeras of Europe and the Mediterranean which will be published in November.  With Marianne Taylor’s recently published tribute to the often misunderstood gull and the eagerly awaited Sharks of the World due in 2021, NHBS are delighted to announce Wild Nature Press as our Publisher of the Month for November.

Save up to 25% on Wild Nature Press titles

Throughout November we will have special offers on all WNP titles, giving you the perfect opportunity to explore their books: below we have selected some highlights, or you can browse their whole range here.

Field Guide to Sharks, Rays and Chimaeras of Europe and the Mediterranean
By: David A Ebert and Marc Dando
Paperback | Due Nov 2020 | £21.99 £27.99
Illustrated key guides enable the reader to identify down to species and comparison plates of similar species and plates of teeth also aid identification.

The Gull Next Door: A Portrait of a Misunderstood Bird
By: Marianne Taylor
Hardback | October 2020 | £17.99 £21.99
Reveals deeper truths to these remarkable birds. They are thinkers and innovators, devoted partners and parents. They lead long lives and often indulge their powerful drive to explore and travel.

 

Seaweeds of Britain and Ireland
By: Frances StP D Bunker, Juliet A Brodie, Christine A Maggs and Anne R Bunker
Paperback | June 2017 | £15.50 £19.50
British and Irish shallow seas contain an astonishing 6% of the world’s seaweed species, more than 600 different seaweeds: this books enables divers, snorkelers and rock-poolers to identify them.

The Essential Guide to Rockpooling
By: Julie Hatcher and Steve Trewhella
Paperback  | May 2019 | £12.75 £16.99
Whether you are an individual or family visiting the seaside, or a naturalist wishing to expand your knowledge, this guide shows you how to discover the astonishing diversity of coastal wildlife with nothing more than a net and a bucket.

Sea Squirts and Sponges of Britain and Ireland
By: Sarah Bowen, Claire Goodwin, David Kipling and Bernard E Picton
Paperback | July 2018 | £13.50 £17.99
Includes sea squirts found in Britain and Ireland’s shallow waters and most recognised sponges. Whether you are a student, a diver, a rock-pooler or simply an enthusiast, this is an essential companion.

Sharks of the World: A Fully Illustrated Guide
By: David A Ebert, Sarah Fowler and Marc Dando
Hardback | Due Feb 2021 | £34.99 £41.99
Packed with unique colour illustrations, line drawings and photographs that are well-presented and easy to use, Sharks of the World is the only single guide to cover over 500 of the world’s shark species

Browse all our Wild Nature Press books at NHBS

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

British Wildlife has expanded!

Editor, Guy Freeman

Since its launch in 1989, British Wildlife has established its position as the leading natural history magazine in the UK. NHBS first took on responsibility for publishing British Wildlife in 2016, and in August this year we were excited to announce that the magazine will be expanding, with the addition of two extra issues per volume. Here, British Wildlife’s Editor talks more about this change and highlights a small selection of the many fascinating articles published in recent issues.

This autumn has been a busy one for British Wildlife as, after 31 years as a bimonthly, we have begun our move to publishing eight times per year.

The main driver for this change has been the sheer volume and quality of articles we have received in recent years, and the sense of frustration at watching these sit on our hard drives for many months before they make it to print! The move to eight issues will speed up the publication process and, we hope, leave us better placed to track the most important developments in nature conservation. In a time of such rapid change, both in the fortunes of our wildlife and the world of environmental policy, the need for informed commentary and expert analysis is greater than ever. In British Wildlife, we will provide a forum for discussion of these topics while continuing, as always, to showcase the delights of natural history in Britain and Ireland.

Our additional space also provides the opportunity to bring further variety to some of our regular features, including through occasional contributions from guest columnists and expanding the coverage of our ever-popular wildlife reports section (see the October issue for our debut plant galls report, and look out for further additions over the next year).

The first November issue of British Wildlife

As part of the expansion, last week saw our first ever November issue go to the printers. Subscribers can look forward to articles on a varied mix of subjects, including:

  • the story of discovery of autumn swarming by bats
  • the potential to create an alluvial floodplain woodland – a habitat lost from Britain – in the Usk Valley, in Wales
  • the conservation of one of Britain’s largest and rarest spiders, the Fen Raft Spider
  • the diverse wildlife and habitats of Muir of Dinnet National Nature Reserve, in Aberdeenshire
  • The limitations of photographs for identifying insects and the need for specialist recording

A number of other fascinating topics have appeared in recent months.

Highlights in October included an overview of the conservation and biology of the Critically Endangered European Eel – the most heavily trafficked wild animal in the world – along with a summary of the difficulties brought upon the conservation sector by the COVID-19 pandemic, and a detailed behavioural study of the common, yet often overlooked, Speckled Bush-cricket.

British Wildlife, August 2020

Our August issue explored the topic of island biogeography through the lens of the Scilly Isles and their unusual wildlife, the spectacular effect of beavers on wetland habitats, and the remarkable world of hybridisation between orchid species.

And in June, we covered the folklore and natural history of the Jackdaw, the amazing diversity of the Ardeer Peninsula, which is currently threatened by development, and the identification and biology of Britain’s ten species of froghopper, or ‘cuckoo-spit insect’.

The above includes just a small selection from recent issues – for a full list of articles and other features, visit the British Wildlife website.

Individual back issues of the magazine are available to buy through the NHBS website, while annual subscriptions start from just £35 – sign up online here.

If you know someone who might enjoy British Wildlife, gift subscriptions – complete with a free British Wildlife mug – are available through the NHBS website.

The NHBS Guide to Moth Trapping

What is moth trapping?

Moth trapping typically involves the use of an artificial light source such as a Mercury Vapour or Actinic bulb to attract moths during the night. In a traditional moth trap the bulb is suspended over a box into which the moths fly, and from where they can be examined and identified before being safely released. However, it is also possible to use the bulb in combination with a white sheet (either laid flat on the ground or suspended vertically using poles and lines) in order to view the moths that are attracted to it. Obviously this technique relies on the light being attended so that moths can be observed as they arrive, as opposed to with a box-style moth trap which can be left unattended overnight and the catch checked in the morning.

Several different types of moth trap are widely available. Take a look at our previous blog post for more information about the most common types of trap; including the Robinson trap, Skinner trap and Heath trap. Options include those which are powered by the mains, as well as battery powered models.

Alternative methods of attracting moths for survey and identification include sugaring, whereby a sweet solution (such as a mixture of treacle, sugar and ale) is painted onto a wooden post in order to attract moths. Similarly, wine-roping involves saturating a natural-fibre rope in a mixture of red wine and sugar for a couple of days and then hanging it from a bush or tree. Both of these methods are most effective during the autumn, winter and early spring when natural sources of nectar are at their lowest. Another very easy method of searching for moths simply involves using a torch to search tree trunks for resting individuals. This low-tech option is particularly fruitful between November and March when there are fewer flying moths and when a light-based moth trap is less effective.

Buff Tip. Image by L Wilkes.
When is the best time for moth trapping?

In general, in the UK, a moth trap can be used from early March to November with varying degrees of success. In woodland habitats they will be effective over more of the season, whereas in open habitats, they are more useful between mid-April and mid-September. Peak months for moth trapping tend to be July and August.

Traps should be set up during the final hour or so of daylight and left to run overnight or for several hours if you wish to stay and monitor the catch. Otherwise, you can simply return at first light to see what your trap has caught. Robinson traps are the only style of trap that will retain all of the catch but other designs such as Skinner and Heath traps still have good retention rates.

Some of the stunning species commonly arriving at moth traps in the UK. Images by O Haines.
Where should I put my moth trap?

For many people, particularly beginners, the easiest place to begin moth trapping is in the garden. Those with a wide range of flowering plants, especially species with scented flowers such as Jasmine, Honeysuckle, Buddleia and Fuschia, will be particularly attractive to moths. If you own a battery-powered trap (or a generator) then woodlands (broad-leaved or coniferous), wetlands and coastal areas are all good options; each are home to a different range of species.

Traps using a Mercury Vapour bulb, which are much brighter than Actinic ones, are particularly suitable for open habitats and in woodland rides, whilst Actinic traps work well under the canopy or in the understory.

Make sure that you get permission from the landowner of the place where you are trapping. If you wish to trap in a nature reserve, always contact the reserve manager for permission – usually they will be more than happy to give this, particularly if you provide them with the records of species caught afterwards.

What else do I need to know?

• Placing several egg boxes in the base of your trap provides captured moths with a textured surface and a variety of gaps and crevices to roost inside. It also makes emptying the trap easier in the morning, as egg boxes can be removed individually for checking.

• Placing a white sheet underneath often attracts moths that do not enter the trap itself.

• Having a selection of tubs or pots at the ready can be useful for temporarily holding individual moths for further examination. Pots with a magnifying lid, or a separate hand lens are useful for picking out the finer details, particularly on smaller specimens. When handling moths, be as careful as possible not to touch their delicate wings, as the oils on your hands can be damaging to them.

• When trapping in a garden, it is important not to run your trap on consecutive nights, as this increases the chance of the same individuals being trapped on a repeated basis. (In large gardens, this problem can be avoided if it is possible to release the moths at least 50m away from the trapping sight).

• Make sure that moths are released in an overgrown location to minimise the risk of them being predated by birds. If you wish to release them in the evening, cover the trap and place it in a cool, shaded location during the day.

• The weather can be extremely important when choosing which nights to trap. Warm, still nights with plenty of cloud cover are likely to produce the best catches. Strong winds, heavy rain and clear nights, particularly when there is a full moon, will be less productive. Nights with a steady drizzle, however, should not be avoided and can be surprisingly good for trapping.

• Records of your catches can be kept and submitted to your local county recorder, or uploaded on the National Moth Recording Scheme website. This information will help to inform conservation efforts for moths and their habitats at both local and national levels.

A good field guide is invaluable in identifying your catch. Image by O Haines.
Recommended identification guides

Field Guide to the Moths of Great Britain and Ireland
#243658

The third edition of this notable field guide has been fully revised, updated and restructured. Moths are illustrated in their natural resting postures, and there are also paintings of different forms, underwings and other details to help with identification.

 

Concise Guide to the Moths of Great Britain and Ireland
#246490

This concise guide is a companion to the main Field Guide to the Moths of Great Britain and Ireland by the same expert authors, but is in a condensed form with artwork opposite the species descriptions and lay-flat binding for ease of use in the field.

 

Field Guide to the Micro-Moths of Great Britain and Ireland
#243663

This ground-breaking book is the most comprehensive field guide to micro-moths ever published and for the first time makes this fascinating and important group of insects accessible to the general naturalist.

NHBS In the Field – Dino-Lite WF4915ZT Wireless Microscope Kit

Within the last 15 years the availability and quality of USB digital stereo microscopes has vastly improved, and these fantastic devices are now regularly used by naturalists and hobbyists looking to view the hidden details of the natural world.

Dino-Lite are a well-known manufacturer of USB microscopes. Their range comprises basic models for those new to the field of microscopy, alongside cutting-edge models that produce stunningly detailed high-quality images and have additional features such as wireless video streaming.

We recently tested the Dino-Lite WF4915ZT Wireless Microscope Kit. This kit is from Dino-Lite’s professional range and it includes an AF4915ZT microscope and a WF-20 wireless adapter. The AF4915ZT is a dynamic microscope and has a number of features which are not available on more basic models. These include: Extended Depth of Field (EDOF), which helps achieve greater overall focus on surfaces with varying heights; Enhanced Dynamic Range (EDR), which helps when viewing objects with large variations in brightness; Flexible LED Control, which allows you to turn on/off pairs of LED lights to achieve the best possible illumination; and Automatic Magnification Reading, which allows the DinoCapture software to automatically register and display the current magnification.

Our aim was to see how easy and intuitive the device was to setup and use, and to explore the benefits offered by its advanced features and wireless functionality.

How We Tested

First we installed the included DinoCapture 2.0 software onto our computer. All DinoLite USB microscopes come supplied with this program loaded onto a CD-ROM, however it is also available online as a digital download. We tested the microscope using DinoCapture 2.0 on a desktop computer, however, you can also use this microscope wirelessly on either a smartphone or a tablet via the free DinoCapture app.

The WF-20 module was charged overnight and then connected to the AF4915ZT. The WF-20 was easy to attach, as the wired end piece of the AF4915ZT has two release buttons which, when pressed simultaneously, allowed us to gently remove this module and then connect the WF-20. When powered on, the WF-20 appears as a wireless network on any nearby Wi-Fi devices. Once connected to this network we were able to view a live feed from the microscope on DinoCapture.

We used the microscope to view a number of plant and insect samples.

Moth eye – viewed with Extended Dynamic Range
What We Found

The 1.3MP resolution is certainly a big improvement over some of the more basic models. Using the microscope at some of the higher magnifications is hugely rewarding, as you are granted some fantastic views of the minute details that are otherwise easily missed. The advanced features (as listed in the introduction to this review) may not be entirely noticeable to those new to digital microscopy, however, compared to older and more economical models they make operating this microscope far simpler. Previously, one would struggle at times to deal with structures having varying levels of brightness (particularly common with iridescent insects for example), and have little control outside of the overall LED brightness to try and address this. However, with the great LED controls and EDR the overall image can be brought closer together and previously obscured features become visible in much greater detail.

The EDOF is also a really helpful tool, especially at lower magnifications and on specimens with a variable structural height (which in our case was an acorn cup and a seed pod). Despite the differing heights, the microscope was able to keep most of the specimen in focus. Both the EDR and EDOF take around five seconds to process, meaning you can view the results and adapt your settings quickly to achieve the best image possible.

Manoeuvring the microscope freehand was relatively easy as it only has a few buttons on its main body, so there wasn’t any accidental mis-clicking. The focus ring is also light enough that it can be manipulated using only the middle and index fingers. Trying to keep the microscope steady and operate the DinoCapture software at the same time was rather difficult, especially at higher magnifications, and so when taking any images I opted to use the device with a stand (specifically the Dino-Lite RK06A). This allowed me to configure the microscope into the perfect position and then operate the computer without fear of losing that positioning.

When used in its wireless configuration we did find that occasionally there were moments of lag on the live feed. While these were only minor interruptions, it was certainly something that had to be considered when making any adjustments to the magnification and focus.

Leaf: (a) Normal mode, (b) with Extended Dynamic Range
Seed pod: (a) Normal mode, (b) with Extended Depth of Field
Acorn: (a) Normal mode, (b) with Extended Dynamic Range, (c) with Extended Depth Of Field
Feather
Our Opinion

Although we only used the WF4915ZT on a few select samples, it offered us a great opportunity to learn how to operate this advanced USB microscope. Thankfully the literature provided with the microscope was clear and easy to follow, and within 15 minutes of opening the box I was able to install the software and connect to the device in both its wireless and wired configurations. The image quality and the benefits offered by its advanced settings were also hugely impressive, particularly the EDOF, which really stands out as a key feature for this microscope.

While the wireless functionality of this microscope was a very interesting feature of the WF4915ZT, in practice it is not necessarily universally valuable. In the study of Natural History for example, most microscopy happens at a desk on pre-prepared specimens and as such you do not need the greater manoeuvrability that a wireless microscope offers. In other trades, however, these digital microscopes are used to inspect large objects (e.g. automobile manufacture) and in these situations a lack of trailing wires would be of huge benefit for the operator. In a situation where the operator does not have access to a computer/laptop, the Wi-Fi module allows you to connect to the microscope using a tablet or a smartphone, which is especially useful if you are planning to use it in the field.

In summary, we would highly recommend the WF4915ZT for any hobbyist or professional looking for a high quality and portable USB microscope. The AF4915ZT would be an excellent (and more economical) alternative for those who are unlikely to use the device away from a desk.


The Dino-Lite WF4915ZT is available through the NHBS website.

To view our full range of USB microscopes, visit www.nhbs.com. If you have any questions about microscopy 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.

How to Clean a Nest Box

Over time nest boxes can become home to parasites such as lice, fleas and mites, so giving them a thorough clean at the end of each breeding season is good practice to ensure the health and safety of the birds nesting there. Removing old nest material also means that the following year’s birds can build their own nest as far as possible from the box entrance hole, thus reducing the risk of predation.

When to clean your nest boxes

The best time to clean out your nest boxes is in the autumn, after any young birds have fledged. Any time between September and January is fine, but bear in mind that birds who have raised a late brood may still be occupying boxes throughout September. By cleaning boxes during October or early November, you will also be able to leave them undisturbed for birds to roost in during the winter. Unhatched eggs may only be legally removed between 1st September and 31st January (or 1st August and 31st January in Scotland) and any eggs must be destroyed.

What you need

• Rubber gloves
• Stiff brush or nest cleaning tool
• Boiling water
• Wood shavings/clean hay (optional)

What to do

1. If possible, remove the box from the tree/wall so that you can safely work at ground level.
2. Wearing rubber gloves, remove old nesting material from the box, along with any unhatched eggs. Eggs must be disposed of – it is illegal to keep them. If possible, try to remove the nest in one piece, as it is fascinating to study the structure and to see the variety of materials that have been used in its construction. This is a great thing to do with children!
3. Use a nest cleaning tool or stiff bristled brush to clean out any remaining debris from the box corners.
4. Use boiling water to kill any lice, fleas or parasites. Don’t use soap, insecticides or flea powders as the residues of these can be harmful to birds. Leave the box open, preferably in a sunny spot, so that it can dry out.
5. Placing some clean hay or wood shavings in the base of the box may encourage mammals to hibernate or birds to roost in the box over winter. This is not essential, however, and any nesting birds arriving in the spring will bring in their own nest-building material.

Cleaning Bird Feeders

While you’re in the garden cleaning your nest boxes, why not take the opportunity to clean out your feeders and bird table too, ready for use over the winter. To thoroughly clean a bird feeder, first empty out all of the old food. Mix up a solution of animal-safe disinfectant in a bucket and soak the feeders for 10-15 minutes. Use a bottle brush to scrub them then rinse thoroughly in cold water. Leave feeders to dry before refilling.

Health and Safety

By following a few simple guidelines you can make sure that both the birds’ and your own health are not compromised. Always wear rubber gloves when cleaning out your nest boxes and feeders and make sure to wash your hands and forearms well with hot soapy water when you have finished. Take care not to breathe in any of the dust when emptying out the remains of old nests. Both nest boxes and feeders should be cleaned outside rather than bringing them into the house. If possible, nest boxes should be removed for cleaning, as dealing with boiling water while perched at the top of a ladder is not advisable. All brushes and equipment used for cleaning boxes, feeders and bird tables should be cleaned after use and should only be used for this purpose.


Visit nhbs.com to see our complete range of nest boxes, feeders and bird tables.