The Batlogger S2 is a compact passive recorder manufactured by Elekon. This all-in-one static bat detector and ultrasonic recorder is designed to be left unattended in the field over several nights to survey and monitor bats. The S2 is operated solely via Bluetooth and the BATLOGGER Control App (available on iOS and Android). It is small, weighing only 138g and measuring 132 x 72 x 35mm, but despite its size, the S2 is robust. It is waterproof and replacement microphones are also available, handy if the original microphone becomes damaged or loses sensitivity.
Elekon has designed the S2 to be easy to use and lightweight, and built to withstand fieldwork conditions. We took the opportunity on a warm evening in mid-May to test the S2’s ability.
How we tested
The S2 was set up in a hedgerow in South Devon, close to a small known roosting site.
We connected the S2 to the BATLOGGER Control App on an iPhone via Bluetooth. Once connected, the S2 determines the dusk and dawn times using the GPS location from the phone/tablet, and suggests these as automatic trigger times. We selected this automatic time window, but, you can choose and customise your own and set multiple time windows as needed.
The S2 is full spectrum with a range of 10-150kHz and a sample rate of 312.5 kHz. The default sensitivity is balanced, and we adjusted the sensitivity to ‘high’ using the App. This may lead to several unwanted calls in busier environments; however, it also ensures that it is triggered by most types of bat call, including social calls, which can sometimes be missed.
Once collected from the field after one night of deployment, the recordings were downloaded from the S2 to a computer using the USB-C to USB-C cable (if you do not have a USB-C port, you’ll need an adaptor). Helpfully, the S2 is charged using the same USB-C cable – a single charge provides 100 hours of power!
The recordings are stored on an internal microSD card, and the S2 generates two file types: an audio file (.wav) and a recording information file (.xml). The audio files allow you to listen to your recordings through bat call analysis software and the information files store important metadata such as date, location, recording time, and device settings.
What we found
The BATLOGGER Control App shows you the number of sessions recorded – the high sensitivity triggered 192 audio files over one night. We used the BatExplorer software to manage and view the S2 recordings. The software has key features such as automatic bat call detection, making sorting files very easy, and it also provides suggestions for species identification.
Of the 192 audio files, 40 of these identified the common pipistrelle (Pipistrellus pipistrellus). The default S2 sensitivity is ‘balanced’, this may have led to a smaller number of unwanted files (which recorded sounds other than bats). But we did not want to miss a bat call and the BatExplorer software allows you to quickly filter the unwanted files.
The echolocation frequency for common pipistrelles is approximately 45kHz, and the below images show an example of the spectrogram and call measures from a common pipistrelle recording taken at dusk and the information popout that BatExplorer produces, detailing the automatic analysis that the software carries out.
Below is an audio clip with its accompanying spectrogram of a common pipistrelle taken at dusk. The BatExplorer software allows you to customise the playback and how the spectrogram can be viewed.
Our opinion
The physical design and key features of the S2 makes surveying bats a simple task.
The S2 truly is discrete and lightweight, making it easy to set up in the field, and once deployed the battery life will allow up to 10 (10 hour) consecutive nights of surveying.
The setup through the BATLOGGER Control App is straightforward. The S2 conveniently uses the GPS location on your phone/tablet to determine dusk and dawn which benefits the accuracy of the recording schedules. You can choose your settings at a click of a button, and the instruction manual is clear and accessible for any help needed.
The only limitation we found is that you cannot access the recordings straight from the App. However, transferring the files across to your computer allows you to listen to and analyse the audio files with ease. The BatExplorer software (available on a 30-day free trial) enhances analysis as it allows you to review, manage, and organise your recordings.
The S2 is an impressive bat detector, and it is an ideal choice for professionals and ecological surveyors.
The Elekon Batlogger S2 can be found here. Our full range of passive full spectrum bat detectors can be found here.
If you have any questions about our range or would like some advice on the right product for you then please contact us via email at customer.services@nhbs.com or phone on 01803 865913.
Deer are among the UK’s most elegant and familiar mammals and sightings of them in their natural habitat are always special moments, however these encounters can often be fleeting, and our views obscured.
This ID guide covers all of the native and non-native deer species that are found in the UK, and describes the key features to look out for to aid in their identification.
Deer are hoofed ruminants that comprise the family Cervidae. They are naturally found across Europe, Asia and the Americas and can be divided into two subfamilies, differentiated mostly by their bone structures. Most familiar in the UK are the Cervinae or old world deer subfamily, which includes the red, sika, fallow, Chinese water and Reeves’ muntjac. The Capreolinae (new world) sub family includes the roe deer as well as elk, reindeer and all the species found across the Americas.
Of the six species found in the UK, only the red and roe deer are truly native, although fallow deer were thought to have been first introduced to Britain in the 11th Century from the Mediterranean region, so are long established. Three other species, the sika deer, Chinese water deer and Reeves’ muntjac are all more recently naturalised within the UK.
Identification of deer can be straightforward in some situations, but some species are similar and, when not seen well, identification can be a challenge. Two of the best features to focus on for identification are the rump and the antlers, if they are visible. Except for reindeer (caribou), in which both sexes grow antlers, and the Chinese water deer and musk deer, which lack any antlers, all male (stags) deer usually grow antlers, which they use in battles to access females (hinds) during the rut. Antlers are unique to deer and a great tool to look at to identify different species. However, they are shed every year after the rut, so although a striking feature, the rump pattern of deer is perhaps the most reliable feature to use for identification.
Distribution: Widespread in Scotland and abundant in the Highlands and Islands. Elsewhere populations occur in Cumbria, Lancashire, the Peak District and Pennines, Exmoor and the Quantock Hills, the New Forest, and East Anglia. There are also small populations in Wales and Ireland.
Head and body length: 1.6–2.6 metres for a male and 1.7–2.1 metres for females
Height at shoulder: 1.14–1.22 metres.
What to look for: Both our largest species of deer and land mammal, the magnificent stags can weigh in at around 200kg making them an impressive and noticeably large species. Look for their reddish-brown coat that lacks any spots or delineation of colour. Only their rumps and tails feature a paler buff cream colour. Another characteristic of red deer are their elongated faces and large ears.
Their favoured habitat is woodland, although in Scotland they have adapted to live year-round in more open treeless landscapes. Grasses make up the bulk of their diet throughout the year, but they will also browse on a wide range of shrubs, young trees and bark, brambles, bracken and heathers. Sika deer are the most similar looking and the two species have hybridised in several regions. Sika have white spots in summer and darker brown coats in winter with shorter faces. Hybrid red and sika deer tend to resemble smaller darker red deer than they do sika.
Antlers: The antlers of mature stags are wide and branching with usually 8 sets of points per antler that curve upwards and sometimes in on themselves. Younger males have short unbranched, straighter pointed antlers.
Rump: A soft creamy colour with a very short russet-brown tail.
Distribution: Sika deer are native to Japan, Korea, Taiwan and far eastern Asia, but escaped into Britain from collections in 1860. Since their initial introduction in 1860, they have naturalised and spread to many regions. Population strongholds include Dorset and the New Forest, Lancashire and Cumbria Northern England, the Scottish borders and the Highlands.
Due to their genetic similarities to red deer, sika deer are thought to have hybridised with the native red deer in several regions, particularly in the Scottish Highlands. Sika prefer to keep to woodland cover more than red deer which have adapted to feeding in more open habitats.
Head and body length: 1.2–1.9 metres for a male and 1.1–1.6 metres for female.
Height at shoulder: 1.07–1.22 metres.
What to look for: Sika are very similar in appearance to red deer and the two species do interbreed in many regions. They are noticeably smaller than red deer and in summer they have white spots on their coats, but thick and often dark (sometimes almost black) coats in winter.
Their diet and feeding habits are very similar to red deer, with grasses and heather making up the bulk of their diet, but they will also browse on both deciduous and coniferous trees, gorse, holly bark and acorns. They are however generally less social than red deer and outside of the breeding season, both males and females can be solitary with females forming only small herds with young.
Antlers: Similar to those of red deer, but thinner, lighter coloured and less complex with usually only 4 points per antler.
Rump: A conspicuous white rump patch with a dark edge and a short white tail with a single thin dark dorsal stripe along its length.
Distribution: A woodland specialist that’s rarely found far from some woodland cover, although they are increasingly using hedgerows and scrub as cover within more agricultural and urban landscapes. They are widely distributed throughout the UK but absent from Ireland, with the greatest population densities found in Scotland.
Head and body length: 0.95–1.25 metres
Height at shoulder: 0.6–0.75 metres
What to look for: A medium sized lightweight deer with a long neck and uniform brown coat. Other features that distinguish them from the larger deer include shorter muzzles and a clean white rump patch. In summer their coats turn a rich reddish brown and appear sleeker, while in winter, the coat turns a thicker and dark more peanut brown.
They are mostly solitary but sometimes form small family groups with young, particularly during the winter. They browse a wide variety of trees, shrubs and herbs including bramble, heather, and rosebay willowherb but during the autumn will also feed on the ground on fruits, acorns and occasionally fungi.
Antlers: Short and mostly vertical, they are rarely much taller than the head, with only 2 or three points per antler. With a close view, the antlers can often appear particularly velvety or crusty at the base, depending on the season and growth stage.
Rump: The patch varies between the sexes, but both have a clean white patch and no visible tail. Males have a kidney shaped white patch, whereas females have more of a round shape.
Distribution: The Chinese water deer is a native of eastern China and Korea but has formed a naturalised population in England after escaping from Woburn Park in Bedfordshire towards the end of the 19th Century. They’re found throughout most of East Anglia and a more scattered population in the southeast-England where there is suitable habitat. The strongholds include the Norfolk broads and Cambridgeshire fens. The population trend is increasing, with over 1500 individuals and their distribution is also expanding. Interestingly, it is thought that due to population decline in their native range, the British population may now represent a significant part of their world population, despite not being a native species.
Head and body length: 1 metre
Height at shoulder: 0.7–0.95 metres.
What to look for: A small and uniformly light brown (sometimes greyish) coloured deer with large, rounded ears and a distinctive black nose. They are strongly associated with freshwater marshland habitats where they feed on coarse grasses, reeds, herbs and aquatic vegetation. Chinese water deer are solitary and secretive, preferring to keep close to cover and use both woodland close to wetlands and reedbeds. They will occasionally forage in farmland but prefer to keep close to cover.
Males have impressive and prominent downward pointing tusks instead of canine teeth that can be seen with a close-up view. These tusks are used during the rut, mostly for display purposes between rival males and to impress females. They are quite a distinctive looking deer with a more unusual almost bear-like face, although their secretive nature means that obtaining good views can be difficult.
Antlers: This species lacks any antlers.
Rump: Their rear and short tail is the same pale brown colour as the rest of their coat.
Distribution: The Reeves’ muntjac is also native to China and again its UK population derives from escaped individuals from Woburn Park in Bedfordshire from 1901. They are now abundant and found throughout southern, eastern and central England spreading rapidly into southwest-England, Wales and southern Scotland. Since 2000, a population has become established in Ireland and Northern Ireland.
Head and body length: 0.9–1 metres
Height at shoulder: 0.45–0.52 metres
What to look for: A very small, robust and stocky deer that often appears to have a hunched-over appearance due to its short neck, arched back and tendency to walk with its head facing down to the ground. The coat varies from a deep russet brown in summer to a greyer and paler brown in the winter. The face is short and squat with a characteristic set of black stripes creating a V shape on the top of the head. Male muntjac also have slightly protruding tusks but they are much shorter than those of Chinese water deer and rarely visible without a close view.
Muntjac favour dense undergrowth within both deciduous and coniferous woodland but will also thrive within urban environments with suitable cover. They browse woodland leaves and flowers during the spring and summer including some scarce woodland ground flora species. During the autumn and winter their diet switches to nuts, fungi and grasses.
Antlers: A single very short point that curves back.
Rump: The rear patch and tail are the same reddish-brown colour as the back. The tail is short but when alarmed it will often raise the tail revealing the white underside.
Fallow Deer (Dama dama)
Fallow deer by Heather Smithers via FlickrFemale fallow deer by Steve Slater via Flickr
Distribution: Introduced to Britain for hunting in the 11th Century and to Ireland in the 13th Century from the Eastern Mediterranean, the species is now found throughout England, with more scattered populations in Wales and Scotland.
Head and body length: 1.45–1.55 metres for a male and 1.30–1.45 metres for a female.
Height at shoulder: 0.7–0.95 metres
What to look for: Fallow deer are quite variable in their appearance due to their wide range of pelage (hair). Typically, most individuals have some conspicuous white spots on pale brown, fawn or gingery coats in the summer and then dark brown coats with only faint or no spots in the winter. There is a great range of variation within this species though with some individuals and populations remaining very dark or very pale throughout the year, some of which can be melanistic. Fallow are medium sized deer that are very social, often forming large herds that remain together throughout the year. Due to their numbers, they also leave conspicuous signs of their presence such as runs and tracks in frequented areas.
Their preferred habitat is open deciduous woodland but will also use farmland and woodland edge habits if there is cover close by. Fallow deer are grazers with grass forming most of their diet, although they will also eat nuts and browse on heather, holly and some deciduous trees to a lesser extent.
Antlers: Very large, broad and palmate shaped with numerous spikes.
Rump: A clean white rump with a darkoutside edge. The tail is long and appears mostly black because of a long black stripe that runs down the course of its length, but the underside is clean white.
The Elekon Batlogger M2 is a sophisticated bat detector, designed for use in active transect surveys and bat walks. The detector is ergonomically designed and compact in its build. Unlike the Batlogger M, the replaceable microphone is set back within the casing, reducing the chance of breakages if accidentally dropped.
It is an easy-to-use detector, able to record ultrasonic calls over a wide range of 10-192Hz, retaining details of the harmonic structure and amplitude of the original bat call.
This detector also includes features for real-time heterodyne monitoring scheduled recording and several preset recording modes for typical survey types, including ‘Explore’, ‘Transect’ and ‘Passive’. There is also an option to create your own presets, with all settings accessible directly on the Batlogger M2.
The recordings can be easily and quickly managed and analysed using the free BatExplorer Software for Windows. This software also includes computer-aided species identification.
How we tested
In August 2021, we tested the Batlogger M2 on Dartmoor in South Devon at dusk. We chose an area with both open moorland and woodland to monitor the dusk emergence of several bat species. Using the ‘Explore’ recording mode, the device was set to real-time heterodyne monitoring, with the trigger settings selected to 45Hz.
The recordings were stored on a 16GB MicroSD card, output via WAV and XML. The files can be easily transferred to your computer with the included cables (a USB-C to USB-C cable and a USB-C to USB-A adapter) however, we simply used an SD card reader to access and transfer our recordings.
Elekon’s ‘BatExplorer Lite’ software was used to visualise and analyse our recordings.
What we found
At only 222g, this device is lightweight, therefore it was not a hindrance when hiking to the site. It was easy to hold and operate in low light, which is important as it will often be used in conjunction with other equipment while undertaking surveys. However, the buttons do not light up or glow in the dark, therefore it is important to familiarise yourself with the setup beforehand.
Our survey used the ‘Explore’ recording mode however, we looked briefly at the other preset modes and felt they would be very useful if carrying out these types of surveys. In particular, the ‘Transect’ mode allows you to pre-program the detector with your own GPS survey route, which will then display directions to keep you on path.
Setting up our recording session was quick and easy. When triggered, the detector automatically recorded the calls in full-spectrum, therefore no further operation was required. Each recording logs the GPS location, temperature, humidity and brightness at the time of recording, so there is no need to bring separate equipment for these parameters. The device also has an integrated voice microphone to enable you to take time-stamped voice notes while surveying, which allows for more accurate note-taking than writing in the dark.
The screen display was bright and easy to view in the dark. The main screen shows the current recording time and frequency, as well as amplitude and harmonic structure of the previous bat call, the time since the last sequence and the species suggestion for that recording. The other recorded information can be accessed by pressing the left and right buttons to switch screen displays, allowing for an uncluttered screen and fewer distractions.
We tested the detector’s audio output with both earphones and through the built-in speakers (includes an adjustable volume). Both had clear audio with little background noise.
We recorded multiple calls including over 60 calls during one 30 minute survey. We were impressed with the quality of the recordings and the lack of ambient noise assisted in the identification of calls. It is worth noting that the M2 uses a SiSonic microphone, whereas the older Batlogger M uses an FG Knowles microphone, so experienced Batlogger M users may notice a slight difference in their recordings.
Automatic species identification was not always to species level, with some recordings having no suggested species. Those that were suggested, however, appeared mostly accurate when we analysed the recordings via the BatExplorer software.
Our opinion
The Batlogger M2 by Elekon is a very easy-to-use and accessible detector. The preset recording modes are useful for almost all circumstances and allow quick survey set up without the need to trawl through complicated settings – particularly helpful for newer ecologists. The only limitation we found was the lack of visual aids for the buttons in the dark, however, this can be easily overcome by familiarisation and repeated use.
It is clear from the design of the M2 that Elekon has acted on feedback from the Batlogger M and have created an intuitive detector with a robust build, perfect for any survey needs.
The Elekon Batlogger M2 can be found here. Our full range of active bat detectors can be found here.
If you have any questions about our range or would like some advice on the right product for you then please contact us via email at customer.services@nhbs.com or phone on 01803 865913.
Rabbits and hares are species in the family Leporidae, which contains over 60 species. They are mammals within the order Lagomorpha, together with the pikas. They are small to moderate-sized species, characterised by long hind legs, long ears and rapid movements. They are almost exclusively herbivorous, feeding mainly on grasses and herbs, although they do also eat leaves, fruits and seeds. Leporids are coprophagous, meaning they pass food through their digestive system twice. To do this, they first expel the food as soft green faeces, termed cecotropes, which they then reingest, eventually expelling it again as dark faecal pellets. This increases their ability to break down and digest plant material, extracting further nutrients.
They inhabit a wide range of habitats, from mountains and wetlands to forests and grasslands. Leporids play an essential role in many of these ecosystems, as seed dispersers, ecosystem engineers (a species that significantly modifies their environment) and as a primary prey item for a number of predator species, such as foxes, wildcats and some mustelids, including stoats and weasels. Their young are particularly vulnerable to these predators, as well as badgers, domestic cats and several birds of prey. Because of this vulnerability, many leporids have large litters, often nesting in burrows underground to protect their young from predation.
One threat to populations, particularly in European rabbits, is myxomatosis, a disease caused by the poxvirus Myxoma virus. Its two natural hosts, the tapeti and brush rabbits of South, Central and North America, experience only mild disease. However, myxomatosis is a severe and usually fatal disease in European rabbits. When the disease originally spread to the UK in the early 1950s, the mortality rate was 99%. In the 1970s this declined to between 47 and 69% but populations were severely affected. The disease, which causes localised swelling, skin lesions, blindness and respiratory distress, has also been deliberately introduced into the wild on multiple occasions. Used to try to eradicate or control rabbit pest populations, myxomatosis was intentionally introduced in Australia, New Zealand, South America and parts of Europe, including Britain.
Other threats to leporid populations include rabbit haemorrhagic disease (RHDV1 and RHDV2), hunting, habitat loss and agricultural intensification. Rabbit populations declined by 64% in the UK between 1996 and 2018 and numbers of brown, mountain and Irish hares are also thought to have declined in some areas. As ecosystem engineers, the loss or reduction of these species can have major consequences, particularly for rabbit-dependent habitats. In their absence, the consequent changes in vegetation structure due to a lack of grazing can have further impacts on other wildlife, such as invertebrates.
Rabbit (Oryctolagus cuniculus)
Distribution: Widespread across the UK, although they are absent from Rum, Isles of Scilly and some smaller islands. What to look for: Rabbits are the smallest leporids in the UK, with the characteristic long ears and long hind legs. They have a sandy, grey-brown colouration and a white tail. They have dark, amber coloured eyes. Other than their size, the most noticeable difference between rabbits and other leporids in the UK is the lack of a black tip on the ears. Did you know? The rabbit, also known as a coney, is not native to the UK. The exact date of their introduction is one of ongoing research. It was previously thought that rabbits were first introduced by the Normans in the 11th or 12th century as both a food and fur resource. But the recent re-examination and radiocarbon dating of a bone found at a Roman palace show that at least one rabbit was present much earlier, in the first century AD. Researchers have stated that there is no evidence of many rabbits in the area and another analysis suggests the rabbit was kept in confinement, therefore it has been suggested that it was most likely kept as an exotic pet.
Distribution: Widespread across the UK, although they are less common and more restricted in Northern Ireland and absent from parts of north-west Scotland. What to look for: This species is larger than the rabbit, with long, black-tipped ears and very long hind legs. Their colouration is redder than the rabbit and the mountain hare, and they have a black-topped tail that is white underneath. The brown hare has amber eyes and their fur can appear grizzled. Did you know? This species is also non-native and were introduced in the Iron Age. Radiocarbon dating of bones found in Hampshire and Hertfordshire, along with historical accounts, suggest that brown hare were not eaten until hundreds of years later during the Roman period, and were instead associated with deities.
Distribution: Mainly in the highlands of Scotland, although they are also found in other areas of Scotland, on some Scottish islands and in the Peak District. What to look for: This species has a grey-brown coat during the summer and a white coat in the winter, although the tips of their ears remain black in both forms and their tail remains white. They have brown eyes and long ears, although these are shorter than the brown hare’s.
Brown form: Andrew via FlickrWhite form: John Johnston via Flickr
Irish hare (Lepus timidus hibernicus)
Distribution: Widespread across Ireland What to look for: They are very visually similar to the mountain hare, except they do not develop a white coat during winter months and are noticeably smaller. During the summer, their coat is reddish-brown which dulls to grey-brown in winter, although their tail remains pure white. Did you know? The Irish hare is a subspecies of the mountain hare and is the only lagomorph species native to Ireland. Fossil carbon dating suggests that these hares have been present in Ireland for at least 30,000 years.
Distribution: Unknown What to look for: Domestic rabbits can have a huge variety of appearances, with at least 305 breeds of domestic rabbits around the world, although different numbers are accepted by different organisations. They can vary in size, colouration, body shape, coat type and ear length. Did you know? Many pet rabbits are abandoned each year, particularly in the period after Easter.
This festive season, why not consider giving a gift that will also support your local wildlife. Wildlife populations in the UK are facing serious threats and many species are in decline, however there are ways in which we can protect and help at-risk species by creating havens for wildlife in our own gardens. At NHBS we sell a range of products, from bird feeders to hedgehog houses, that can both bring joy to the recipient and benefit wildlife at the same time. We also sell a number of books that can help you create a wildlife friendly garden. We’ve put together a selection of some of our favourite items for you to browse below.
Hedgehog numbers have dramatically declined in recent years. Creating a hole in a garden wall or fence will allow your local hedgehogs to pass through from garden to garden safely.
Many bird species are struggling to find enough suitable natural nesting sites in the modern environment, but a bird box will provide a warm, sheltered substitute, with protection from most types of predators, helping to improve the chances of breeding success.
The Frogilo Frog and Toad House provides a safe retreat for frogs and toads in any garden and is handmade in frost-resistant ceramic with a decorative glazed roof.
The National Trust Apex Insect House is an ideal addition to any wildlife friendly garden. With a variety of shelter types, it offers a perfect habitat for important invertebrates such as lacewings, ladybirds, and even some butterflies.
Bee Bricks are made in Cornwall in England using the waste material from the Cornish China clay industry. They provide much needed nesting space for solitary bee species such as red mason bees and leafcutter bees, both of which are non-aggressive.
A large and beautifully coloured and glazed bird bath with a ‘ripple’ step design that is both visually attractive and functional by providing extra footing/grip for wild birds.
The Defender Feeder’s metal construction is tough, long lasting and offers excellent protection from squirrel damage. The feeder is available with two, four or six feeding ports, each with a perching ring that allows birds to feed in a natural, forward facing position.
Hedgehog numbers are rapidly declining across the UK and providing a refuge in your garden with the Wildlife World Hedgehog House will help to protect hedgehogs from predators and disturbance.
This is a guide for anyone wanting to garden in a more sustainable, natural way. Working with nature benefits not just the garden, but also the gardener, wildlife and the wider environment.
This shows you how you can provide a refuge for bumblebees to feed, breed and thrive. No matter how large or small your space is, Dave Goulson shows you how you can make a pollinator-friendly haven.
This offers a fresh and unique perspective on ponds, encouraging readers of any budget to reach for the spade and do something positive to benefit their shared neighbourhood nature.
If you want to attract more bees, birds, frogs and hedgehogs into your garden, look no further than this. Kate Bradbury offers tips on feeding your local wildlife and explains how you can create the perfect habitats for species you’d like to welcome into your garden.
Discover more great gift ideas on our website. Plus, check out our two blogs on how to attract wildlife to your garden.
The Bat Conservation Trust’s annual National Bat Conference, held online via Zoom from 29th–31st October, covered many aspects of bat conservation through a wide variety of activities and talks, including monitoring, surveying and development. We are extremely pleased to have sponsored this event and we were lucky enough to have been able to attend many of these sessions, including talks by Professor Tigga Kingston from Texas Tech University on the human dimensions of bat conservation, and Thomas Foxley, University of the West of England, who spoke about the role of landscape features in spatial activity patterns of greater horseshoe bats. We also attended a few of the amazing workshops that took place, such as Shirley Thompson’s gardening for bats.
Bat Conservation Trust update
Bat Conservation Trust also shared an update on their current and future work. Bats make up more than a quarter of all mammal species in the UK, but sadly, these species face many threats. Habitat loss and fragmentation, decreasing food resources, chemical use, disturbance to roosts and threats from cats have all led to a dramatic decline in bat populations over the last century. Diseases, wind farms, flypaper, artificial lighting and the presence and construction of roads also negatively impact.
Lesser horseshoe bat (Rhinolophus hipposideros) bats roosting by Jessicajil via Flickr
Currently, Bat Conservation Trust supports a number of local bat groups, working with volunteers, scientists, industry and government on a range of projects. They focus on discovering more about bats, taking action to protect them, inspiring people to care about bats and strengthening their work by improving relevant skills and knowledge. Their programmes include a National Bat Monitoring Programme, education and engagement, the National Bat Helpline, Landscapes for Bats, and science and research.
During this update, Bat Conservation Trust spoke of the many ways they will be increasing their efforts to help bat populations, for example by increasing the spread of their monitoring programs and organising a petition regarding key amendments to the Environment Bill, including legally binding targets for wildlife recovery. Through new acoustic and monitoring approaches, they also aim to improve their evidence base and Bat Conservation Trust are also working towards improving their engagement with policymakers, the public and the media. Their Bat in Churches project has also been expanded to include training on bat care basics, surveying a church, the best architectural practices for bats and cleaning workshops.
One key scheme they are developing is the Bat Roost Tree Tag Scheme where recognisable tags are placed on trees that contain bat roosts. The aim of this is to make sure all trees that have been surveyed and found to contain bat roosts are easily identifiable. When woodland managers and workers see a tag on a tree, they will know to seek advice before proceeding with work. This will also give a significantly increased level of protection for ancient trees, which are vitally important for a large number of species.
Future events and how to get involved
The National Bat Conference was a very interesting and educational event, and it was wonderful to see such a wide range of knowledge and skillsets being shared through the many talks, activities and workshops throughout the weekend. If you missed out this time or would like to attend further events, the Bat Conservation Trust has a number of future events planned, including Spring into Action, Midlands Bat Conference and the East of England Bat Conference. More information about these and other events can be found on the Bat Conservation Trust website.
There are a number of ways you can help to support Bat Conservation Trust, such as by becoming a member or donating. You can also contact your local bat group, fundraise for bats or volunteer for their various projects. However you choose to get involved, you can make a real difference to the future of bats in the UK.
Mustelids are species in the family Mustelidae of the order Carnivora. They are medium to small mammals comprising around 56-60 species worldwide, eight of which are found in the UK, including feral ferrets. While the conservation status of most is considered Least Concern in Great Britain, several of these species are considered Critically Endangered or Near-Threatened in individual UK countries. This is mainly due to historical and current persecution and habitat loss. Pollution, however, has also impacted mustelid species, such as the otter, which was particularly affected by pesticides, such as organochlorines. Thankfully, many of the most harmful pesticides have been banned in most European countries since 1979, allowing populations to begin to recover. Other conservation efforts, such as legislative protection, habitat restoration and relocations, are also helping to restore mustelid populations.
Mustelids, other than badgers, are characterised by their long, thin body shape, which allows them to enter burrows and tunnels used by their prey. These mainly include rabbits and small mammals, but also some birds, bird eggs, invertebrates and fish. Several species resemble one another, particularly the stoat and the weasel, but several key identification features can help you to correctly identify the species. Colouration, body size and distribution within the UK can be helpful, as well as other features such as tail size, shape and colour, snout shape and even their running gait. Binoculars or a scope can help you to identify these features from a distance.
Polecat (Mustela putorius)
Distribution: Found throughout Wales, parts of Scotland and central and southern England. Body length: 32–45cm Tail length: 12–19cm What to look for: This species has dark brown guard hairs, the top or outer layer of the coat, and buff-coloured underfur, giving them a two-tone appearance. They have a dark face with a white stripe across it, similar to a ferret. They can produce hybrid offspring with ferrets that can be difficult to identify, but the hybrids usually have a lighter appearance and more white on their faces.
Distribution: Mainly found in Scotland and Ireland, although fragmented populations are found in northern England and North Wales. Body length: 46–54cm Tail length: 18–27cm What to look for: The pine marten has a chestnut-brown colouration with a pale yellow patch on its chin and throat that resembles a bib and a long, bushy tail. The ‘bib’ is uniquely shaped on each pine marten, meaning individuals can be identified by the pattern.
Distribution: Widespread throughout the UK, although absent on the Isles of Scilly, most of the Channel Islands and some Scottish islands. Body length: 17–32.5cm Tail length: 6.5–12cm What to look for: This species is orangy-brown with a cream-coloured underside and throat. They have a very similar appearance to the weasel but there are some key differences: the stoat is larger, with a longer, black-tipped tail and a distinctive bounding gait compared to the run of the weasel.
Distribution: Widespread in England, Wales and Scotland but is absent from Ireland and most islands. Body length: 11.4–26cm Tail length: 1.2–8.7cm What to look for: The weasel is the smallest species of Carnivora in the UK, with a russet-brown coat that can appear more orange in certain lights, and a cream underside and throat. Their tails have no black tip and are much shorter compared to the stoat’s tail, and they run with a straight back, rather than the arched, bounding gait of the stoat.
Distribution: Widespread across the UK, thought to be absent from the far north of Scotland and some Scottish Islands. Body length: 31–45cm Tail length: 13–23cm What to look for: The mink has dark brown fur with a white chin and throat and a narrow snout. They can resemble otters but they can be distinguished by their smaller size and face, as well as their darker fur. Did you know? The American mink is an invasive species, introduced into the wild in the 1950s and 1960s as a result of fur farm escapees and deliberate releases. Accurate population estimates are difficult but many areas are attempting to control numbers as American mink are a serious threat to the endangered water vole (Arvicola amphibius).
Distribution: Rare but widespread throughout the country, although absent from areas in central and southern England, the Isles of Scilly, the Isle of Man and the Channel Islands. Body length: 60–80cm Tail length: 32–56cm What to look for: This species has brown fur with a grey tint, a paler chest and throat and a broad snout, which can be used to distinguish it from the mink. Did you know? In the UK, otter populations were in severe decline in the second half of the 20th century, due to hunting, pollution from pesticides and habitat loss. Conservation efforts have allowed populations to start to recover, with otters returning to every county in England.
Distribution: Widespread throughout England, Wales, Scotland and Northern Ireland. Absent from far north Scotland, Scottish Islands, the Isles of Scilly, the Isle of Man and the Channel Islands. Body length: 75–100cm Tail length: 15cm What to look for: This is a distinctive species, with a grey back, black underside and paws, a fluffy, short tail and an unmistakable black-and-white striped face.
Distribution: Feral populations throughout Britain, but thought to survive best on offshore islands, such as Shetland, Mull, Harris, Islay, Rathlin Island and North and South Uist. There is also a population in North Monaghan. Length: 48–56cm (including tail) What to look for: This species has multiple colour variations, including white, brown, black or mixed fur. Their nose is usually pink, although they can have darker blotches, and they have a thin white band across the face with darker eyes, giving it a bandit-like appearance. They can be hard to distinguish from the polecat, from which it is descended. Where there is an established population of both species, hybridisation can occur. Patches of white on the fur, particularly the paws, can indicate either a ferret or a hybrid.
Bats are elusive creatures; they are nocturnal, and so you are less likely to spot them compared to other UK wildlife, despite bats making up almost a quarter of our native mammal species within the UK. Some species have experienced severe declines, although current trends indicate that a few of these are now recovering. There is still much to learn about bats, however, and ongoing monitoring plays an important role in improving our knowledge of bat population trends.
Where to find them?
Bats are more likely to be found roosting in natural crevices, as opposed to building nests like birds or other small mammals. They can roost in trees, roofs, or outdoor cavities in buildings such as houses, as well as other natural or manmade structures, such as caves and bridges. As they hibernate during the winter, bats are the most active between April and November, and the best time of day to watch them is at dusk. They’re found in many habitats, particularly woodlands, farmland and urban areas (such as gardens).
Identifying Bats:
There are 17 species of bats that have breeding populations in the UK. They are commonly identified by their calls, as the rhythm, frequency range and repetition rate varies between species. A bat detector can be used to easily identify individual bat species in the field; you can browse our range here. In this article, however, we will be looking specifically at the physical characteristics that aid in the identification of 11 of our more common bat species.
Their size, colouration, nose shape, and the size and shape of their ears are helpful features to look at when identifying them by sight. More complicated identification features include the presence and size of the post calcarial lobe, a lobe of skin on the tail membrane, and the length of the forearm.
Pipistrelles
The most common species, and the ones you’re most likely to see, are pipistrelles. There are three species, the common pipistrelle (Pipistrellus pipistrellus), the soprano pipistrelle (P. pygmaeus), and the Nathusius’ (P. nathusii), with the first two being the most common and widespread of all UK bat species.
Common pipistrelle by J P via FlickrSoprano pipistrelle by I. Watson Loyd
ID notes: All three species look very similar, with dark brown fur, a paler underside, and a darker mask-like pattern around the face. Nathusius’s pipistrelles are rarer, and slightly more easy to tell apart due to their lighter underside, larger body size, and furrier tail.
Size: 3.5-4.5cm in length (Nathusius’: 4.6-5.5cm)
Wingspan: 20-23cm (Nathusius’: 22-25cm)
Great and Lesser Horseshoe Bats
Latin names:Rhinolophus ferrumequinum and R. hipposideros
Lesser horseshoe bat by Alexandre Roux via FlickrGreat horseshoe bat by Nils Bouillard via Unsplash
ID notes: Both these species have a fleshy nose shaped like a horseshoe. The lesser horseshoe is much smaller, with greyish-brown fur on its back and a white underside, while the greater horseshoe is larger and has more of a reddish-brown colouration on its back and a cream underside.
Size: Lesser: 3.5-45cm in length, Greater: 5.7-7cm in length
ID notes: The whiskered bat is quite difficult to distinguish as they are visually similar to Brandt’s bats. They have brown or dark grey fur with gold tips, and a lighter grey underside. They have a concave posterior edge to their tragus, the piece of skin of the inner ear in front of the ear canal, whereas Brandt’s bats have a convex posterior edge.
ID notes: This bat has brown fur, a paler underside that appears silvery-grey, and a pink face. This species is most likely seen around water as they forage for small flies above and on the water’s surface.
Size: 4.5-5.5cm
Wingspan: 24-27cm
Brown and Grey Long-eared Bats
Latin name: Plecotus auratus and P. austriacus
Brown long-eared bat by Javier Ábalos via FlickrGrey long-eared bat by Alexandre Roux via Flickr
ID notes: These bats, as their names suggest, have very long, large ears which can be almost the same length as their bodies. These species look very similar, with greyish-brown fur, although the grey long-eared bat has a darker face.
Size: Brown: 3.7-5.2 cm, Grey: 4.1-5.8cm
Wingspan: Brown: 20-30cm, Grey: 25-30cm
Natterer’s Bat
Latin name: Myotis nattereri
Natterer’s bat by I. Watson Loyd
ID notes: The Natterer’s bat has a bare, pink face and light brown and grey fur on its back, with a paler underside. Its ears are quite long, and it has bristles along its tail membrane.
Size: 4-5cm
Wingspan: 24.5-30cm
Bechstein’s Bat
Latin name: Myotis Bechsteinii
Bechstein’s bat by I. Watson Loyd
ID notes: The Bechstein’s bat has long ears which, unlike the barbastelle’s, do not meet at the forehead. Their fur is reddish-brown with a paler, grey underside, and a pink face.
Size: 4.3-5.3cm
Wingspan: 25-30cm
All bat species are European protected species, therefore they and their breeding and resting sites are fully protected by the law. It is important to note that a licence is required for capturing and handling bats, as well as for any activity that may disturb a bat roost, including photography.
Acoustic detection is a popular and widespread method of environmental assessment, and its use is increasing, driven by the development of increasingly accessible and sophisticated detection devices. The Handbook of Acoustic Bat Detection provides an in-depth understanding of the principles of acoustic detection, study planning, data handling, properties of bat calls, analysis of results, and the manual identification of species. It also includes information on quality assurance, the benefits and drawbacks of automatic species recognition, and the background physics of sound.
We are fortunate to have had the opportunity to ask the authors some questions.
The applications of data derived from acoustic bat detection are diverse and wide-ranging. What motivated you to write The Handbook of Acoustic Bat Detection and what impact do you hope the book has in this field?
In our daily work, we have seen a lot of improper use of acoustic data. Mainly driven by misconceptions regarding the interpretation of acoustic data and quite often due to missing basic knowledge on bioacoustics and signal analysis. With the easy availability of acoustic detectors and the relative simple usage, these problems became more common, especially in consulting activities. Many new “bat experts” appeared in the field basing their work on automatic detection and identification systems. We hope to help such users to gain a basic understanding of bioacoustics and give more experienced users new information to further improve their work. Thus overall we hope to improve the quality of projects based on acoustic data and increase the evidence level.
This book discusses some of the different methods for processing acoustic data, such as zero-crossing. What are the benefits of this method versus full-spectrum analysis?
The main benefit of zero-crossing is the much smaller amount of data produced and the possibility of listening to the recorded sounds directly. Full-spectrum detectors produce much larger amounts of data and do not allow direct listening to the bat calls. Yet, the benefits of zero-crossing are decreasing with cheaper data storage and higher processing power. Thus today one can nearly instantaneously listen to full-spectrum sound resampled to zero-crossing or heterodyne representation in real-time. In our opinion, the real-time data gives more insights into the calls on a much easier-to-understand level, yet we accept that experts can do powerful analysis with zero-crossing data as well.
You have all had many years of experience in this field; how has bat detection and acoustic analysis developed and changed since you first started?
We started working on bat acoustics in the field when only heterodyne or zero-crossing detectors were available. So in our early days, we walked through the field listening for bats. We were already interested in better and more reliable species ID back then. Then the time-expansion system was available as well as the Anabat system. We used time-expansion a lot, but both didn’t work well for our scientific research interests. So we developed with the batcorder a real-time detector that completely changed bat work in Germany within a few years. Back in the beginning, sound analysis of bat calls was something only a few were able to do. Now with fully automated systems, the whole process changed. Surveys can run for multiple months nearly everywhere – not only ground-based but also on wind turbines or off-shore. We collect billions of bat calls a year with these systems and thus are able to learn more about their calls and ecology. Yet this is not always the best, since a lack of bat knowledge often prevents optimal solutions for bat-related landscape changes.
Bat acoustic recording visualised through the Anabat Insight Software
In chapter 11, ‘Quality assurance of reports’, you provide criteria to improve the quality of specialist reports used in impact assessments, such as which information should be included and the procedures that should be followed. How do you think the previous lack of clear guidelines has impacted bat surveying and, consequently, conservation?
In Germany, quite often surveys were conducted and it was later not possible to understand the low or high results since important information was missing. Also for legal complaints in planning processes, it was quite often impossible to understand how the data was actually sampled. If surveys and methods are well documented, it is much easier to evaluate the planning process and even more to work out optimal sampling schemes for following surveys in the new planning processes.
Now that this book is complete, do you have any future projects you would like to tell us about?
There are many projects – especially since we now face a major green-green dilemma with climate conservation often acting against biodiversity conservation. This especially is visible in the renewable energy sector. So currently some of us are investigating chances to further identify the possibilities of improving bat conservation for planning wind parks and other sources of renewables.
Another project is the ongoing improvement of species identification based on bat calls. We are working on new solutions to give better results.
Here we review the Anabat Scout from Titley Scientific. The Scout is an easy to use active bat detector that offers excellent quality live audio and recording, plus many handy surveying features and durability that sets it apart from other detectors. It uses heterodyne, auto-heterodyne and frequency division audio that can be recorded in either full spectrum or zero crossing files.
Designed with professional surveyors as well as the more serious bat enthusiast in mind, the Scout is an ideal detector to take on bat emergence and transect surveys. This is thanks to great features such as a bat counter and GPS tracking transect mode.
How we tested
In early July 2021, we tested the Scout outside an old barn in South Devon to monitor the dusk emergence of several bat species. The building was known to host many common pipistrelles, brown long-eared, lesser horseshoes and some myotis species. We wanted to see how easy the detector was to use in the setting of a busy emergence and get a feel for its recording quality and its special features. The audio was set to auto-heterodyne to see how good this feature would be with multiple bats close by. Under the trigger settings is the option to adjust the sensitivity, which we set to high as there was unlikely to be too much undesired noise in this setting.
What we found
Firstly, it is worth noting just how lightweight (at 160 grams without batteries) and easy to hold the Scout is with its handy wrist lanyard and comfortable fit within your hand. These features are particularly important when undertaking long surveys and holding other equipment such as a clipboard for instance.
The OLED display screen is small, but bright, so key information such as peak frequency and time is easy to note in the dark. With just key information visible, the screen does not become too “busy” unlike some detectors, which in some circumstances is a real advantage as it avoids too much distraction. The buttons all glow in the dark, which we found very useful once it had become completely dark, as it kept navigation simple, without having to use a torch.
One of the Scout’s most handy features are the in/out bat counter buttons which enable you to easily tally the number of bats recorded coming out and back into a roost, without the need to look away to make notes and perhaps miss bats. The counter also time and date stamps and geotags each count (CSV file output), so saves you having to manually note this data.
The Scout has a transect mode which notes a GPS coordinate every second so maps out your route as you walk it. It also logs another GPS coordinate for every bat recording made which produces detailed transect maps.
We found that the adjustable volume control was very good and loud enough when needing to compensate for background noises such as a passing lorry.
Also noteworthy was the Scout’s ability to record voice notes. Once it has become fully dark or if you are surveying and need to keep your eyes fixed on bat watching, then the ease of just speaking into the device to add survey notes or further information is very helpful.
The Scout was very productive at picking up all the bats we encountered during the evening (although sometimes a brown long-eared emerged without calling and was missed). The auto-heterodyne tuning to the peak frequency was superb and saved much time. On a few occasions, we switched to manual heterodyne which enables you to adjust the frequency by moving the up and down arrows. This setting would be useful when first teaching beginners. The Scout’s range is also excellent, which was demonstrated when a high flying noctule was picked up probably over 30 – 40 meters away.
Two recordings taken on the Anabat Scout and visualised through the Anabat Insight Software.
The recordings were always clear through the built-in speaker, although there is also the option to attach a 3.5mm headphone jack. All recordings come with GPX track files attached. This gives accurate GPS data, that when viewed on the free software: Anabat Insight, a .KML (Keyhole Markup Language) file can be generated using Google Earth which will show your route with location tags for each bat recording.
All recordings were stored on an SD Card (recommended min: 32GB and max 512GB) and then output via WAV (Full spectrum) and Anabat sequence files (Zero Crossing).
Battery life lasted roughly 10 hours on 2 x AA (NiMh, Alkaline or Lithium) batteries with the remaining memory space and battery life displayed on screen, so we could keep a check during the evening.
Our Opinion
The Anabat Scout is certainly one of the easier to use, professional bat detectors available. It is highly accurate with its triggers and by being so lightweight and practical it makes for an ideal choice for both ecological surveyors and keen naturalists alike. The Scout has been designed with the needs of surveyors in mind and even those new to bat detecting, will find it simple to use and highly rewarding.
The main limitation found was that the Scout does not display full spectrograms like the Anabat Walkabout, therefore beginners particularly, may not find this detector so helpful for learning the differences in calls and identification in the field.
Overall, we feel the Scout offers very good value as an active detector that will fulfill the needs of most ecological surveyors. Its advantage of being incredibly easy to use and get to know, makes it fantastic for beginners, subcontractors and educational purposes also.
The Anabat Scout can be found here. Our full range of active bat detectors can be found here.
If you have any questions about our range or would like some advice on the right product for you then please contact us via email at customer.services@nhbs.com or phone on 01803 865913.