The addictive nature of research – Lesser Horseshoe bats in Bowland.

The object of all our effort.

It’s that time of year again when survey effort switches from the anti social dawn and dusk hours to the easier daytime, and we start to head underground to monitor swarming and hibernation sites.

Like Captain Ahab and his white whale, a somewhat smaller mammal has been keeping us searching for four years now since we first encountered a Lesser Horseshoe bat while out surveying caves in Bowland, Lancashire on Halloween (you couldn’t make it up).

The cave in question has a peak in temperature from mid October to mid November and our theory is the the bats use this to extend feeding opportunities a little bit longer as the nights get cold. And then they disappear possibly into inaccessible areas to hibernate.

From the DNA work we’ve done so far we know the Bowland bat seems to take a more basal position to current populations in North Wales and Somerset supporting our theory that we’re dealing with a remnant of the former northern range of the species rather than a recent arrival. Lessers survived in Yorkshire until 1944 in the Helmsley area so it’s not too hard to believe that an overlooked colony in a little surveyed area of ideal habitat survived unnoticed.

But the advances in our knowledge of the species here have come scattered amongst a whole load of survey effort (I don’t want to add up the hours) a bit like the return on a slot machine that makes them so addictive.

So we’re at that point again when an encounter will fill in another little gap of information, one step closer to understanding. Addictive, frustrating, time consuming and verging on an obsession but so so worth it, let’s face it if there wasn’t a challenge, if the answers came easily, it wouldn’t be half as much fun would it?…

Anabat Roost Logger

Anabat Roost Logger


I had a good look at the Anabat Roost Logger over the weekend of the National Bat Conference and Chris Corben was good enough to install the drivers on my laptop as well as hand over a folder of recording to get a taste of what it’s capable of recording.

On first look I’m interested. Whilst it isn’t a full blown recording detector capable of species identification, the Roost Logger will enable measurement of activity and identification to genus level. Whilst the microphone is most sensitive at 42khz the results included Lesser Horseshoe calls though the bats have to be within a couple of metres to record from what I’m told. For research into swarming and roost sites this should prove very useful for finding out when bats are active and getting an idea of what you’re likely to encounter. So Roost Logger deployed first to see where to focus survey effort and more expensive kit makes perfect sense.

The whole kit is enclosed within a small pelicase which should make stashing the detector fairly easy in most sites.

I’ve got an Anabat Roost Logger on the way for review and will be getting it straight out monitoring a cave so expect a review by the end of October……

A new Anabat on the way? – Updated

It looks like Titley Scientific are about to release a new version of the Anabat built specifically for long term monitoring in caves, tunnels and roosts.

Anabat Roost Logger

The features all seem sensible enough:

  • Long running times on internal batteries
  • Temperature logging
  • Waterproof case
  • Sealed mic

The rugged peli case style housing looks up to the job and the (let’s hope) waterproof mic will be a great step forward for Anabat. But it raises the question; will the sealed mic be available to retrofit existing detectors?

A long time bugbear of the Anabat when used underground is the, what seems to be, inevitable burn out of the mic once condensation builds. My record is 5 mics in a season monitoring Myotis swarming sites, not just an expense but also frustrating because of lost data and downtime.

As an existing user I don’t want to replace the Anabats I already own, I want a mic that allows me to use them without that headache. It’s one reason I’ve been contemplating switching to the SM2Bat+ from Wildlife Acoustics.

Let’s hope there’s some good news for existing users too.


With a price of £307.20 the Anabat Roost Logger could be a game changer although that depends if it’s capable of species identification or just Monitoring activity levels and temporal patterns at any roost.

Whilst the Titley webpage states it’s compatible with existing software it’s a bit vague on what information is captured. Activity and species ID for under £500? Maybe that’s a bit ‘moon on a stick’ at the moment.

If it is just an activity logger it’s still a useful bit of kit of course, especially for initial swarming site research, but you’ll need to place more expensive kit in the field to identify what bat species are using your site.

*** Update as of 4.9.2012 Reply from Titley states that the datalogger “still presents data in sequence file and ZCA formats, the same as all previous Anabat units. The major difference is the ability to deploy it for long periods and program it to record selectively as the season changes”.


Preparing for swarming season

One month to go before swarming season is on us again. I’m looking forward to using the UltraMic250k this year to record swarming myotis species at some of my study sites.

Here’s some light readng for anyone interested in the use of underground sites by bats for swarming.

The Ecology and Conservation of Cave Roosting Bats in the Yorkshire Dales

Autumn swarming behaviour of Natterer’s bats in the UK

Cave selection and use by swarming bat species (you’ll need Athens for that one)

Swarming of bats at underground sites in Britain—implications for conservation

The role of swarming sites for maintaining gene flow in the brown long-eared bat (Plecotus auritus)

The effect of gates on cave entry by swarming bats

Swarming of Myotis mystacinus and other bat species at high elevation in the Tatra Mountains, southern Poland

High gene diversity at swarming sites suggest hot spots for gene flow in the endangered Bechstein’s bat

Host–parasite determinants of parasite population structure: lessons from bats and mites on the importance of time Swarming and mite dispersal

Late summer and autumn swarming of bats at Sikspārņu caves in Gauja National Park

Identification and characterization of swarming sites used by bats in Nova Scotia





Want to research bats underground?

Want to research bats underground? Here’s some sources of information on where to look in your area; a perfect spring and summer activity to get prepped for swarming and hibernation seasons.

A word of caution: You need to be licenced to survey hibernation sites. You need to be competent and aware of dangers working underground. Cavers and Mine Explorers are sensitive to bat ‘issues’ so don’t go wading onto forums with requests for information of bats in caves and mines, a bit of diplomacy is called for.

A combination of the sites below should reveal sites you never realised were in your area. Why not approach the local caving group for a spot of joint working?

Yorkshire Dales Cave Maps:

UK Caving:

AditNow – Mine exploration:

Mine Explorer:

28DaysLater Urban Exploration:

Approach your local Sites and Ancient Monuments records team for any records of Ice Houses, Lime Kilns, etc.


Hope R4 headlamp

Hope R4 headlamp – £225 (at time of press)


Pro’s: Very versatile with multiple light levels. Great flood light in larger caverns Good battery life at lower light settings

Cons: Needs second battery for extended trips underground. Overpowered for day to day surveying.

Hope R4 headtorch

Hope R4 headtorch

As part of the East Lancashire Bat Group project “Bats Underground” we’ve been undertaking swarming and hibernation surveys of Rossendale flagstone quarry tunnels where I found the light of my Petzl Spelios a bit underpowered in the larger caverns. This is where the Hope R4 headtorch came in.

The 4 x Cree XPG head unit

The 4 x Cree XPG head unit

The Hope R4 is designed primarily as a bike light but comes as standard with a headtorch adaptor to allow it’s use as a “multisport” light. With 4 Cree XPG LED’s sequenced through the top mounted button to offer 6 levels of light including a  maximum of 1000 lumens this is a serious bit of kit. In truth it’s probably too much even at it’s lowest level for day to day bat surveying, but for large systems it’s superb. The 2600mah li-ion battery offers burn times ranging from 1.15hours on high to 8.00 hours on low, I’ve alsways found the medium light setting to give plenty of light to navigate quarry tunnels while still offering circa 4 hours of light. A larger 5200mah battery option is available.


  • Light Source: 4 x Cree XPG, R5 Bin
  • Light Output: 1000 measured lumens, 1446 generated lumens
  • Beam: Diffused uniform beam (+/- 12.5°)
  • Distance: 105m
  • Battery: 7.4v Li-Ion, 2600mAh
  • Charge time: 3 Hours
  • Weight: 235g (std), 338g (epic), 367g (endurance)
  • Power levels: 6 (two sequences of three), including flash
  • Burn time: 1:15 hrs – 8:00 hrs

Petzl Spelios Helmet/Headlamp

Petzl Spelios Helmet/Headlamp


Pro’s: Great lighting in confined spaces, uses common AA battery, good burn time on LED

Cons: Feels underpowered in larger caverns and tunnels.

Petzl Spelios

Petzl Spelios

The Petzl Spelios is the industry standard for caving helmet/headlight combo’s and for good reason. If you’re considering venturing underground to carry out hibernation surveys or carry out cave research then this is the helmet you need to consider as a starting point.

Spelios showing Duo 14

Spelios showing Duo 14

The lighting element of the Spelios is delivered via an integral Duo 14 LED headtorch which features a switched halogen / LED light. In confined spaces such as small caves and roofspaces the 14 LED array should deliver as much light as is needed but the flood style spread will suffer in larger systems. The Halogen can be focused to an extent but it’s rare that I find a use for it  and it obviously has an impact on battery life compared to the LEDS.

Spelios battery pack

Spelios battery pack

The rear mounted battery pack balances the helmet nicely in use and houses 4 AA batteries. A rechargeable unit is available as an extra purchase but I find it’s just as easy to carry spare rechargeable batteries with you.

The helmet is available in two sizes covering head circumferences of 48-56 cm and 53-61 cm.


  • Beam pattern : wide or focused
  • Max. light quantity : 67 lumens
  • Max. lighting distance : 100 m
  • Max. battery life : 183 h
  • Constant lighting : yes
  • Operates on four AA / LR6 batteries or ACCU DUO (not included)
  • Battery compatibility: alcalines, lithium, rechargeables ni-mh, rechargeables ni-cd
  • Watertightness : IP X8 (waterproof down to -5 meters)
  • Spare halogen bulb included
  • Certification(s) : CE EN 12492, UIAA
  • Weight : 505 g


Alpkit Gamma Headtorch

 Alpkit Gamma Headtorch – £15 (at time of press)


Pro’s: Cheap, great varied light options.

Cons: Sells out quick.

Alpkit Gamma

Alpkit Gamma

I’m a big fan of Petzl headtorches and have been for years but the Alpkit Gamma is a fantastic bit of kit, suitable for every bat worker and you can get three for the price of one Petzl. A bargain.

Gamma close up

Gamma close up

The main XPC Cree LED throws enough light for navigating to survey sites, and has two switchable levels should you need to extend battery life. Once on site and for areas where you want minimum light spillage/disturbance a long hold down of the top button switches to cycle through the three smaller 5mm leds which offer white, green or red light. All three settings should offer enough light for tuning detectors, etc.

Battery life is good, it runs on three AAA batteries and even comes supplied with Duracell as standard. If you’re working on dimly lit road transects the rear battery case has a seperately switched flashing/constant red light which aids visibility.

A great addition to any survey kit bag and well worth getting as a back up for underground too.

Headtorch specs:

  • 1 x XPC Cree LED (up to 88 lumens)
  • 3 x 5mm LED’s Red, White, Green (1.8 lumens)
  • Weight: 118g with batteries
  • Batteries: 3 x 1.5V AAA alkaline (included)
  • Water resistant: tested to IPX4