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……

The future of bat detectors

Don’t get too excited, it’s only a mock up

The basic rule of technology is everyhting gets smaller, more capable and cheaper, though so far the application of that rule to bat detectors seems stalled at the £1000 mark for anything of serious use.

I’ve been using Ultramics for two years now to capture realtime full spectrum recordings at Myotis swarming sites. Up until now that’s required a netbook to run the software, not massively cumbersome but combine it with infrared video kit and a trek across moorland and you certainly feel the weight.

So it was good to hear from Ivano at Dodotronic that they’re working on an android compatible version of the Ultramic; the Ultradroid. A small ultrasound microphone combined with the computing power of a 7″ tablet? The potential to record, geolocate and identify bat calls in realtime all with a full colour easily visible display?

I’ve already bought a Google Nexus7 tablet, I’m ready.

 

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.

UPDATE

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

 

 

 

 

Video and IR LED Illuminator set up

I was so impressed when I saw Pat Waring’s video presentation at the BCT northern bat workers conference I thought I’d build something similar. While Pat’s system from www.batmanagement.com was great it was also quite pricey and would involve importation from the states.

Pat Waring's set up

Pat Waring’s set up

So I headed off the eBay.

I quick search of the term “IR LED Illuminator” brought up a fair array of choices, most of which were located in China or Hong Kong but given a max price of £10 for a 48 led 850nm unit I guessed it was worth a punt. Sit back for a few weeks until the units arrive and then a quick trip to Maplins for the necessary leads and fittings.

eBay IR LED Illuminator set up

eBay IR LED Illuminator set up

 

Video IR setup from the back

Video IR setup from the back

For just under £50 I managed to get a 4 x 48 IR LED Illuminator set up which runs off the same 7ah 12v battery I use through autumn to power remote Anabats monitoring swarming sites.

I’m using a Sony HDR SR5 video camera which has the all essential 0 lux nightshot setting and records direct to a 40gb hard drive (again an eBay purchase – £100 brand new unused).

Note the 850nm illuminators have a very dull red glow when on, but emerging Brown Long Eared bats haven’t been affected by them so I figure in a barn setting they’re unlikely to be a disturbance factor. Last night they managed to pick up non echolocating BLE’s light sampling in the apex of a barn roof it would have been easy to miss if you were relying just on detectors (I was using both Anabat and Pettersson 240x, Anabat missed them and the 240x only recorded very faint echolocations which couldn’t be seen in Batsound v4).

If you’re surveying sites such as barns likely to have Brown Long Eareds or Myotis sp can you afford not to use video to strengthen your survey methodology?

Here’s an example of the footage and detail you can capture (actual footage is fullHD out of the camera)

 

 

Lesser Horseshoes, Museums and DNA

As part of the East Lancs Bat Group research into Lesser Horseshoe Bats in Bowland, Lancashire I headed over to York Museum over the Easter break to sample the Lesser Horseshoe bats in their collections to enable us to carry out some dna analysis.

Lesser Horseshoe bats in the Adam Gordan collection

Lesser Horseshoe bats in the Adam Gordan collection

The Adam Gordan collection is interesting as it provides voucher specimens of two species until recently thought to be extinct in the North; Lesser Horseshoe and Barbastelle bat. In fact the Barbastelles in the collection are voucher specimens for the first Yorkshire record of the species in 1920.

Museum collections such as these which are accompanied by good date and location data are highly important now that dna anaylsis is an affordable tool for bat researchers and groups to use.

In the case of our Lesser Horseshoe research we’re hoping that comparison between former northern range specimens and our current Lancashire population will prove that our bats are a remnant population rather than a recent expansion. Comparison with other current UK populations is hinting at it, but hopefully we’ll have an answer just as soon as the results come back.

There’s a similar bit of research with Barbastelles just waiting for someone to carry it out there. Anyone?

 

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: http://www.cavemaps.org/

UK Caving: http://ukcaving.com/board/index.php

AditNow – Mine exploration: http://www.aditnow.co.uk/

Mine Explorer: http://www.mine-explorer.co.uk/

28DaysLater Urban Exploration: http://www.28dayslater.co.uk/forums/

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

 

Lascar USB2 Temperature and Humidity Datalogger

Lascar USB2 temperature and Humidity Datalogger – £49.95 (at time of press)

From: http://www.lascarelectronics.com/temperaturedatalogger.php?datalogger=102

Pro’s: Small, cheap and easily programmable.

Cons: Batteries need ordering (ebay is your friend here)

Lascar USB2 Datalogger

Lascar USB2 Datalogger

The Lascar USB2 datalogger is small, cheap and a very unobtrusive datalogger that’s perfect for recording conditions in bat roosts and hibernation sites. This datalogger is very suitable for monitoring crevices due to it’s size.

Lascar monitoring crevices

Lascar USB2 monitoring Temp/Rh in crevices used by Natterer's bats

Very easy to program with the supplied EasyLog USB software I tend to set them up to monitor at half hour intervals which means the battery lasts one year even in sub zero temperatures experienced during winter in exposed sites. Shorter intervals are possible but this obviously affects battery life.

With a netbook and a pocket of spare 1/2AA lithium batteries you can download and reset dataloggers in the field with ease.

Data downloads can be viewed either within EasyLog or imported into excel or similar spreadsheet programs.