Navigate that bat!

This is an exciting time for bat survey technology: after a number of years of stagnation the equioment available for surveying bats is taking some serious leaps forward. A number of new pieces of equipment have appeared on the market over the past 18 months and several more will be available soon. But sometimes it's not the equipment that matters so much as how you use it.

I have been using Anabats extensively for a number of years, both for passive monitoring (automatic recording of bats in flight) and for transect surveys(walking or driving a survey route, recording bat activity). The Anabat's ability to be connected to a GPS unit to record grid reference data alongside recorded bat passes is especially useful in understanding bat activity as you can plot the location of each bat pass accurately on a map. However, this tends to take a bit of post-survey work (unless you use a personal computer with your Anabat/GPS combination...but madness lies that way if you're not an uber-geek).

The flexibility and potential of Anabats for generating extensive high quality data has led them to move out of the realm of the professional bat ecologist and into the hands of voluntary bat groups around the UK. They're not cheap at around £1400 each, but many enterprising bat groups have obtained funding and are using their Anabats to great effect, generating lots of new biological records of bats.

A Bat-Nav in place on an Anabat SD1. In practice I found that the magnet wasn't sufficiently powerful to hold it in place (photo copyright Wildwood Ecology)

Recently I came across a new gadget, designed to be used in conjunction with an Anabat. In essence Wildwood Ecology's Bat-Nav acts as a GPS plugged into your Anabat and feeds it grid references as you walk or drive around. It comes with a simple but effective computer Widget, which uses Excel to extract your bat records and GPS file and generate a KML file. This file allows you to see your bat records plotted on Google Earth with a miniumum of fuss.

The Bat-Nav is designed to be used with an Anabat SD2 and draws its power supply from the USB socket on the machine. As I only had an older SD1 available for testing Wildwood kindly rigged up a wire to connect to the positive side of the battery pack, which worked ok. Since then Wildwood have launched a model designed to be used with an SD1.

To test the Bat-Nav in practice I used it to do a car-based survey around my home village one night in September. Wildwood suggest the unit can be attached by it's own magnet to the Anabat's own steel casing. I found the magnet too weak for that, but it stuck to the car door very well.

I recorded plenty of bats during a 2 hour drive. When I got home I used AnalookW to identify and label each bat call and created a count labels file in the usual way (if you've never used AnalookW, it is a delightfully easy to use piece of software for identifying bat calls which, with a few clicks allows you to create a simple spreadsheet). I then opened the data in the BatNav KML generator (see above) and after half a dozen clicks I had a KML file. All I had to do was click on the file for it to open in Google Earth (you probably have to have Google Earth already installed) and here is the result.

The transect route is shown as a yellow line, with each bat pass labelled (I chose to label P5 for Soprano Pipistrelle, P4 for Common Pipistrelle, Psp for unidentified Pipistrelle and Msp for Myotis). For anyone with access to GIS software (and the training to use it) this kind of thing is easily prepared, though it takes a little time. If you don't have acces to GIS or want a quick and simple way of looking at your bat data geospacially, this fits the bill. You can also manipulate the data three-dimensionally in Google earth and even look at it in Google Streetview, as you can see below.

Would I buy one? I think I would, though it's not without drawbacks. The area I chose for my test survey is in open farmland and the terrain is clear to see from the air. A woodland transect would be far less clear, with the tree canopy tending to hide paths and some roads and structures. Sadly Google Earth does not (so far as I know) allow you to convert between the satellite view and a decent map view (for that you need Bing.com/maps, which allows you to use Ordnance Survey maps as well as satellite images. Unfortunately it's part of Microsoft's evil empire, but these are the breaks).

Another niggle is that the magnet is disappointingly feeble, making it less usable for walked transects, but some sticky-backed velcro would probably sort that out.

Of course £150 is rather a lot of cash to shell out, especially if you already have a GPS receiver you could use. A friend of mine said it just took him a couple of hours, playing with Excel and Google Earth, to work out how to produce his own KML files. But he's a bit of a geek (sorry Tom). Perhaps Wildwood should consider selling the KML generator widget separately from the magnetic GPS - they may find some customers who are already happily using a normal GPS with their Anabat, but would like the hassle-free conversion to KML.

Wildwood Ecology - www.wildwoodecology.com

My website - www.plecotus.co.uk

Send me your thoughts/comments - email David Dodds

A major threat to biological recording

If there is one thing which underpins all wildlife conservation work it is biological records. Data on what species live where allows us to understand wildlife better and to plan how best to conserve it. Without biological records we are simply groping in the dark.

A major weakness of professional ecology in the UK (and to some extent amateur natural history) are field skills: the ability to accurately identify species and habitats in the field and record their presence. Universities are churning out ecology graduates who in many cases have spent only a week or two in the field during 3 or 4 years of study. The result is a glut of graduates, but a shortage of graduates who are able to do fieldwork without extensive further training.

Many people turn to postgraduate study in order to address this and by far the best course has for a number of years been the University Certificate, Postgraduate Diploma and MSc courses in Biological Recording run by Dr Sarah Whilde's team from the University of Birmingham, based at the Gateway Centre in Shrewsbury.

Unlike most other courses, these are ideal for those who already work full time and offer enormous choice of species groups to work with. Individual modules are run intensively over 3-5 days at Field Studies Council centres around the country by expert specialists. I was fortunate to study the MSc course and gained enormous benefit as well as great deal of pleasure.

Now these successful courses are under threat. The University of Birmingham took the astonishing decision to close the centre. This is not for financial reasons, in fact they admit that the courses make a strong financial contribution to the university. They wish to close them simply because they do not fit with current research goals at the university. Quite apart from the barking mad concept of a publicly-funded body throwing away a good source of income, the closure of these courses would be enormously damaging to the quality of ecological surveying and biological recording in this country.

After massive pressure the university have conceded that they will attempt to move the courses to another university, but they have made no promises.

Please take a moment to sign the on-line petition against this move and help persuade the university that these courses are too important to conservation and to wildlife education for them to be threatened in this way.

Biological recording petition

There's Nowt So Queer As Folk...

...whom you meet on bat surveys.

Back in May 2008 I wrote about some strange occurrences during bat surveys (What is it about bat surveys? May 2008). It sometimes seems inevitable that if you meet someone during a survey, there will be something less than normal about them or their activities. I thought it was time to update you with a few of the odd characters I have met and strange situations I have found myself in since then.

Sometimes you meet regular-seeming people, who turn out to have a secret. I was recently setting up a survey in a rural area when a farmer stopped to ask if we needed any help. You know you're in a properly rural area when strangers offer help without being asked - antisocial city dwellers please note. I explained to him that we were doing a vehicle survey for bats, showed him the equipment we use and we chatted for a while about bats and wildlife. Like most farmers he was highly aware of the wildlife around his farm. He described the bats he sees around his farmyard and invited me to drive through after the survey and take a look. Having a bit of time to spare later I drove through his farmyard and bats weren't all I saw. Perhaps he had intended to draw the curtains on the room that contained his cannabis-growing operation but was distracted by some livestock emergency...

Meeting the police during bat surveys is a fairly regular occurrence during surveys. If we are doing something liable to look suspicious I used to call the local station and let them know, to avoid wasting their time with an unnecessary visit. These days the local cop-shop is probably unmanned at night and I object to spending half an hour talking slowly to a disinterested call centre person who usually fails to advise the local patrol of our presence anyway. So explaining to bored coppers what we are doing is a regular thing.

Whilst carrying out a dawn survey close to an international airport I had a less run-of-the-mill encounter with some less run-of-the-mill police Officers. During the survey I heard shots fired in the near distance. "Bird scaring at the airport", I thought and carried on undaunted. A little while later, as I was leaving I saw a police car approaching at some speed. Apart from the everyday odd behaviour native to all bat workers I was probably looking especially suspicious. The site I was surveying was a building within a massive security fence. It was just a couple of hundred metres from the main runway of the airport, so just the sort of place your average terrorist might find alluring. And here I was, desperately trying to disguise the fact that I was placing the key to this high security compound under a brick beside the gate (my client's idea and not one I was in a hurry to take the credit for with the boys in blue).

The police car did a rather impressive screechy-wheel stop across the road, matched a moment later by another one. All very interesting...until machine-gun toting airport police leaped out, fanned round me and told me to keep my hands where they could see them. You never really know what you're going to do when placed in a dramatic situation, but my brain was whirling with three slightly worrying facts: these guys clearly mean business, in a moment they are going to ask me to explain my highly suspicious behaviour and my answer is going to involve furry flying animals...

It turned out that, whilst I may look suspicious, I don't look at all threatening (which was actually a bit disappointing). Apparently I had been right about the shots, but someone else had heard and reported them, giving Starsky and his mates an opportunity to go play. The really odd sequel was when, having finished with me, one of them asked me to wait as "the Chief Super wants a word with you". After a few minutes a much sleeker police car arrived and out climbed someone whose uniform had a lot more shiny bits on. This is where things took a surreal turn. It was 5am, I was utterly knackered, having been up since 1am and I had just been held at gunpoint. "They all think this is funny" he said, indicating the now grinning coppers "but I've just been appointed to take over the wildlife crime unit. Do you have time for a chat about wildlife crime priorities?" "Errr...ok". That was a very unusual morning.

On another occasion a police patrol stopped, to enquire if everything was ok, as our car, with an amber flashing beacon on the roof and reflective "surveying" sign on the back was stopped at a slewed angle in the middle of the A7 trunk road late at night. I really didn't have the nerve to tell them the truth: that we were looking for Noctule bats, which are quite rare in the Scottish Borders and I had piled on the brakes and leaped out of the car because we heard one. Not quite a Highway Code manoeuvre!

A couple of years ago I was asked to carry out bat surveys of a large number of primary schools in which it was planned to do extensive work so the local council needed to confirm that no bats were present (owing to their legal status as European Protected Species). The first stage of such surveys is usually a site visit, to check the buildings internally and externally for signs of bats and bat roosts. The schools were supposed to be advised when I was coming but, usually weren't. So, when I walked towards the entrance of one particular school I took a deep breath and steeled myself for the usual protracted explanation about bats, bat surveys, why one was necessary etc before being allowed past the Fort Knox security system that all schools seem to have.

To my surprise I was greeted with "Ooh bats, come in, come in!". "Wow", I thought. "This is unusual." I was ushered inside and pointed out to a passing teacher with "This gentleman has come about the bat." "Oh lovely!" was the response. By this point I was thinking something was a little odd. Not only were they unusually excited about a simple survey visit but they were talking about "the bat." Singular.

I was ushered up to a noticeboard covered in drawings of bats, paintings of bats, essays about bats etc. Alongside was a photograph of a Long-eared Bat and pages from the Bat Conservation Trust (BCT) and other bat-related websites. "I've died and landed in bat conservation heaven." I thought. The photograph was of a bat which had been found above the main entrance of the school the previous week. At first I was delighted. To see a school taking such a positive interest in bat conservation is unusual and fantastic. Bats suffer a great deal of prejudice and the best way to stamp out prejudice is to start with children. Then I thought about the bat.

The bat had been found in an exposed place on the outside wall of the school, within a few inches of an entrance used several times a day by a couple of hundred children. It apparently stayed there for two days before it "decided to leave". Whether this animal had been sick, injured or exhausted isn't clear but it certainly wouldn't have chosen to stay there for two days, being stared at by lots of people if it had an alternative option. I doubt very much that it "decided to leave". Perhaps it was eaten by a Magpie or other predator or perhaps it fell from the wall, to be picked up by a passing cat. Whatever happened could have been prevented, if someone had stopped to think "is this wild animal behaving naturally" and sought advice from BCT or the SSPCA. I suspect the kids who had researched the bat, drawn paintings of it and created a display about it would be rather upset if they learned that, whilst they were doing this, it was starving to death or being eaten.

A photo of the school bat, taken by a parent and enthusiastically bluetoothed to me from her phone.


Annoyingly we did a load of night-time surveys in the hope of finding a roost on the premises and never found any evidence. Wherever it came from, it wasn't the school.


If you find a bat and need help, advice or information contact the BCT Bat Helpline: http://www.bats.org.uk/pages/help.html

If you find a strange human or inquisitive copper during a bat survey...you're on your own.

My website: plecotus.co.uk

A Weekend With Engelbat

I once worked on a bat project with someone whose sense of humour was completely absent. Anyone who knows me will tell you that my sense of humour is ever-present and decidedly peculiar, so things would always be a little difficult! This person was adamant that individual bats should never be given names as it anthropomorphises them, though in my view giving something a name simply labels it and is harmless (it is poor interpretation of behaviour that anthropomorphises a wild animal). The result of this difference of opinion is that, in honour of the humourless one, any bat which passes through my hands is immediately given a ludicrous name. This is how Engelbat (Engelbat Humperdink? Geddit? No? See what I mean?) came to be named.

He was a juvenile Brown Long-eared Bat (Plecotus auritus), found one July morning on the ground floor of a large country house. The house has a known BLE maternity roost in the attic, four stories above, but Engelbat had wandered quite some distance from there and looked rather sorry for himself, covered in cobwebs and tucked under a radiator.

I had no way of knowing why he had left the roost. This site has no history of bats straying into the building. It's possible his mother had died, causing him to become dehydrated and leave the roost in search of water. However, as he was old enough to fly it is perhaps more likely that he got separated from his mother and simply ended up in the wrong place. I often explain to roost owners that young bats are just as likely to do something silly as young humans.

A close-up of Engelbat's wing, showing the clear patches (unossified bone) in his joints which indicate a juvenile.

I don't normally get involved in bat rehabilitation work. It's a difficult, skilled and phenomenally time-consuming job, so I normally pass casualty bats on to those dedicated individuals who excel in it (hats off to Tracey, Carol and Nigel!). However, Engelbat was a bit different in that he was several weeks old and capable of flight. he just needed some TLC and a plan to get him back into the company of his mother.

Having given him a drink of water (always the number one priority with a casualty bat - they can go a few days without food, but dehydration is a swift killer) I checked Engelbat over for signs of injury and found none. I then took him home and installed him in the bat-cage. This is simply a small plastic cage of the type used to transport hamsters etc. Inside is a shallow water-bowl, a glass jar of warm water with a towel wrapped round it (to simulate his mother) and a canvas pouch hanging on one site, to allow him to retreat out of site into a simulated crevice. He quickly grabbed onto the warm sock and settled down and I left him to get used to his new surroundings. Later he left the sock and took a drink from the bowl, before moving up into the canvas pouch: all positive signs.

Engelbat with the warm sock which acted as a mother/colony substitute.

A while later Isla and I got him out of the cage to feed and assess him. He had done a couple of droppings in the cage, indicating that his digestive system was functioning. When offered a mealworm he grabbed it with enthusiasm, but had some difficulty chewing it, a bit like a small child given a hard toffee. Mealworms are the standard food source for casualty bats, but for younger animals their tough outer skins are a bit too chewy. We tried him on "white" mealworms, i.e. those which have recently shed their skins and have not properly hardened. He found these easier, but still struggled, so from then on we fed him mostly mealworm innards. This is a delightful meal to prepare. First slice the head off a mealworm, then squeeze out its insides as though its a tube of toothpaste. The resulting blobs of vile gunk were voraciously devoured. He prove to be a slightly aggressive little bat, using his forearms to "stamp" at anyone who came too close. Male Brown Long-eareds have a reputation for being grumpy when handled and he fitted that stereotype quite well!

A brief video of Engelbat slowly munching his way through a white mealworm.

So far he ticked a lot of the boxes for being capable of rapid release: no injuries, functioning digestive system, eating and drinking well, so the final test was could he fly? He quickly demonstrated he could by flying happily round and round the living room. Brown Long-eareds are slow-flying bats, so the restricted space didn't seem to faze him at all and eventually he astonished us by managing to land and somehow grip a smooth painted wall, which I'd never seen a bat do before. Several more flights were managed with aplomb.

As he was clearly a competent flier for his age that led us towards how to restore him to his colony. Placing stray infants back into roosts is a questionable approach, as it is impossible to know whether the animals mother is still within the colony, or whether the juveniles wandering may be due to her death, for example killed by a predator. If this were the case then returning the juvenile to the roost may not be the best way forward.

After a conversation with Tracey Joliffe (a very experienced bat carer) for a second opinion, we took Engelbat back to the roost at sunset and placed him on a wooden bench which the adults fly over on their way to their feeding grounds. Our expectation was that his mother would encounter him and encourage him to fly with her. As it happened he chose to fly on his own and flew very competently along the flight line used by the colony, into the nearby woodland.

Of course it's impossible to tell the outcome of a casualty bat returned to the wild (unless you are Maggie Brown, who has done some amazing work tracking her casualties post-release, to evaluate their success). Hopefully he fed successfully and returned to the roost with the rest of the colony and hopefully he teamed up with his mother, if she was still alive. We'll never know for certain. Now I have to think up another ridiculous bat name, ready for the next bat who comes to stay...

If you're interested in caring for sick, injured or orphaned bats the best starting point is to speak to an existing bat carer, who can mentor you and help you get going. It's easy to get things wrong and sound advice and support is essential if you want to get it right. Contact your local bat group to find out who does bat care in your area. You can find your local group via the BCT website (and if you're not already a member...join!) . Another great source of information is the "Bat Rescue Manual", published by the West Yorkshire Bat Hospital, who also publish a regular newsletter: "Bat Care News". Your local bat carer will be able to put you in touch.

BCT Website: BCT Bat Groups page

My website David Dodds Ecology

Anabats and Songmeters

I have written before about my good opinion of the Anabat SD1 (now replaced by the SD2, with some minor upgrades), a machine which offered huge advances in passive monitoring of bats (i.e. leaving a machine on site to continuously record bat calls), in use with a GPS receiver for walked and car transects (where a route is followed, recording bat calls and their locations) and for use as a training aid when connected to a PDA personal computer, to display live sonograms of bat calls. Prior to the arrival of the Anabat the only way of doing these surveys was with a Frequency Division bat detector, recording WAV (or poorer MP3) audio files: a massively time-consuming and data intensive process, so the Anabat was a big step forward.

Like all good things, the Anabat had some downsides: reliability has never been as good as it might be, technical support is patchy and confusing and the price (around £1400) is prohibitive for many users. So the arrival of the rival Songmeter SM2 on the UK market last year generated a lot of interest. At around £800 it is clearly cheaper and many bat workers and ecologists were excited to try out the latest generation of bat detector. Personally, I was quite cynical and, having had the chance to use several Songmeters this year, my reservations may have been justified. Let me clear though: I am not saying that the SM2 is not a good piece of equipment: it has a lot going for it. What I am saying is that, just like the Anabat, it has strengths and weaknesses and to claim as some have, that it is a technical advance on the Anabat is simply nonsense!

The two importers of the Songmeter, Alana Ecology and Envisage Wildcare have marketed the Songmeter powerfully in the U.K. and it's arrival on the market suggested that it was a new and exciting development. In fact the Songmeter had been on the market in the U.S., alongside the Anabat for quite some time. Anabat had been successfully sold in the U.K. by both companies for several years and both provided excellent technical support. In early 2010 Titley Electronics (who make the Anabat) suddenly withdrew the product from them and set up a European sales office in the U.K. Deprived of a key part of their product ranges, both companies looked around for a replacement product and settled on the Songmeter. So it's arrival here was a result of commercial necessity, rather than technical development and the flurry of interest in it is primarily a result of marketing hype. So I was interested to get my hands on some Songmeters this year and find out how they match up to the hype.

An Anabat SD1. The later SD2 version has a USB socket on the right-hand side, rather than a serial port. The velcro on the left was stuck on to allow a GPS receiver to be attached for transect work.

A key advantage of the Anabat is the fact that it converts bat call audio to a digital format, so that each bat pass generates a tiny file of around 2-5KB. Thus a 2GB memory card can last weeks or even months, without needing to be replaced. The SM2 records WAV high quality audio, compressed to form WAC files. Theoretically, this allows the creation of better quality sonograms for analysis. Unfortunately, the compression results in very large files, compared to Anabat. My experience of using SM2 has been of long hours spent downloading, copying and converting many tens of Gigabytes of data. The Songscope software supplied by Wildlife Acoustics (the makers of Songmeter) is expensive and unpopular, so that most people use Analook (the Anabat software) to analyse Songmeter data. Wildlife Acoustics supply a free program (WAC2WAV) which converts WAC files to ZCA format, so they can be analysed using Analook. However, running WAC2WAV on large amounts of data (and most passive monitoring produces large amounts of data) is slow and tiresome.

Using Anabats for passive monitoring has always created the problem of waterproofing, leading to many imaginative ways of keeping Anabats dry and free from condensation when used in the field. Unfortunately, long-term use in our wet Scottish climate has always been a problem, with inevitable condensation build-up leading to failure if the machines aren't occasionally taken somwhere warm, to dry out for a few days. The SM2 case is waterproof in itself and needs no further protection. It also addresses the Anabat problems by including "Humisorb" pouches inside the units and having a valve to equalise air pressure inside with that outside. That sounds ideal and would be...if it worked. At present several of the SM2s I am using have proved unequal to the challenge of a cold, wet upland site, with quantities of condensation present inside the machines. In fairness, none has yet stopped working and the manufacturers have proved keen to find a solution. Only time will tell if they are successful.

There is a clear cost benefit in buying an SM2, rather than an Anabat, but there are also hidden costs. A 2GB CF card for an Anabat costs around £15, but a set of four 32GB SD cards for an SM2 could set you back several hundred pounds (how many you need will depend on how often you download data). SM2s have internal capacity for a set of outdated D size batteries. The machines reportedly do not respond well to the lower voltage produced by rechargeable batteries. Happily the machine, like the Anabat, will work with an external Sealed Lead Acid Battery. Unlike the Anabat, you will have to pay around £100 for an external voltage regualator. Oh, and if you want the software designed to be used with the Songmeter, that will be another £500.

Probably my biggest beef with Songmeter is its lack of flexibility. It is a passive monitoring machine. Full stop. Anabat has a range of potential uses, as I described above. The SM2 does have some interesting potential though. For example, it comes with an in-built temperature recording unit. It also has the ability to work with two separate microphones concurrently. Potentially, this allows some interesting studies to be carried out, using extension microphone cables. For example, recording the direction of bat movement along a linear feature such as a hedgerow or comparative studies of bat activity at ground level and at height.

A Songmeter SM2 in position, attached to a post. This unit is being operated with two microphones simultaneously.

Another intersting feature of the Songmeter is it's omnidirectional microphones, which pick up bats in all directions. This is potentially a useful feature in a passive monitoring machine. When a detector is used in the hand we tend to point it at bats we hear, getting the clearest possible calls. When a detector is used passively the directionality of the microphone works against us, so an omnidirectional microphone seems a good idea. However, it has drawbacks too. A microphone which picks up bat calls in all directions also picks up background noise from all directions too, reducing the gap between noise and bat calls. This could easily reduce the clarity of a recording and increase the number of non-bat ultrasound recordings.

My biggest beef with the Anabat has always been it's limited ability to keep accurate time. Over a period of weeks they are fine, but over protracted periods of use the internal clocks tend to lose or gain time. So far the SM2s I have been using have been reliable in that respect. They also have a useful ability to be set to start and stop recording at specified periods before sunset/after dawn, rather than specified start/finish times, as with the Anabat. This saves having to reprogram them through the year, to reflect changing dawn and sunset times.

One colleague I spoke to this year was hopeful that using SM2s intead of Anabats might reduce the number of equipment failures. Sadly that hasn't been my experience. It's easy to think that, when you buy a machine with a high price tag you are getting high quality electronics, but electronic development doesn't really work that way. The major cost in producing any electronic equipment is the initial development cost. If you are developing a new iPod, confidently expecting to sell millions of units, you can afford to invest millions of pounds in perfecting the design. If you are developing a bat detector, with an expected sale of a few thousand units then the development budget is inevitably much smaller. In this respect both machines are in the same boat and they appear to have an equal propensity to fail.

So what would I spend my cash on? Well, the SM2 is an interesting piece of equipment, with some useful features. It had the potential to knock the Anabat for six on waterproofing and reliability, but so far it has proved no better on either score. It lacks the Anabat's flexibility and it's memory-hungry format is time-consuming to manage. So, unless I was involved in a project which could benefit from the specific extra capabilities of the Songmeter I would spend my hard-earned cash on an Anabat.

Wildlife Acoustics (maker of the Songmeter) www.wildlifeacoustics.com

Titley Electronics (maker of the Anabat)

www.titley-scientific.com

Wildcare & Alana (the UK Songmeter importers) http://www.wildcareshop.com
http://www.alanaecology.com


My website: www.plecotus.co.uk