Bat Detector Training

After a long wait during the winter and early spring, it was finally time to learn how to use a bat detector with my favourite ecologist and fellow Arbtecher, Jo Gregory.

The in-house training was to take place in Dalham Park, in the lovely Milnthorpe. The training offered by Arbtech is free and available to anyone interested in emergence bat surveys and bat detector work.  By the time I arrived there was already a large group of bat enthusiasts (even one dressed as a cowboy—different strokes and all that), eager to get detecting!

Jo gave a half hour talk about what we were looking for (bats), how we were going to go about it (through a detector) and what to expect in the process. She also talked about Arbtech’s approach to client work and the importance of having very good admin* if you want to sub-contract to Arbtech; before we headed on down (with the sun) to the park.

* Admin is an all-encompassing term popularised within Arbtech by Rob. Here’s how he describes it:

Admin is an idiom I picked up during my time in the Army. It refers to, for want of a better expression, having your sh*t together. An ecologist who is the most qualified guy in the world isn’t worth the paper his CV is written on if he is disorganised and doesn’t manage his time properly. At Arbtech, admin is the most important thing we do. Get it right and everything else matters very little.

Funny noises and light bulk moments

I’d done a fair bit of reading about detectors (mine is a Wildlife Acoustics EM3; I get the Touch when I am fully trained up, like the rest of the consultants at Arbtech) and echolocation but the best way to get a feel for bat calls is to witness them firsthand through the detector. When researching, you read these odd phrases like listen for a “wet smack” for a common pipistrelle (Pipistrellus pipistrellus) and a “tick” for Myotis species. It all seems rather intimidating but when you actually hear the call in real life, it suddenly makes a lot of sense; the confusion lifts and you think, “Yeah, I get what they mean now!”

The park was a great place to do the training, even though there weren’t any opportunities that night to witness bats emerge from a building; we were lucky enough to hear a variety of different bat species.

This included common and soprano pipistrelles (Pipistrellus pygmaeus), Daubentons (Myotis daubentonii) and Noctules (Nyctalus noctula). The detectors produce different sounds for each of the different species, and also display a frequency readout to further aid identification.

It was a great opportunity to correct some confusion over the pipistrelle species as they sound the same and are both audible within a given frequency band, however you can hear the ‘tinny’ distant sound when a common pipistrelle came though at 45khz and vice versa for a soprano pipistrelle at 55khz.

Next weekend

We went back to the same site the following weekend to do more of the same (get a feel for the calls, ask questions; ‘is this a feeding buzz?’), discuss our findings and get excited to do proper surveys!

First bat emergence survey of the season

I was excited to put my new detector skills to practice while assisting on a real survey with more experience people. (Maybe a little too excited as the others in the group had started to give me strange looks!) I was slightly concerned that knowing my luck, it could be a really complicated site where bats are coming from every possible gap and of all different species and I have a meltdown… (OK and breath).

Actually, it went great. Plenty of bat activity; mainly foraging in the trees beside the house. This was really useful as I could hear them through the detector and gain even more confidence with their identification and feeding buzzes. I did spot some fly into the trees, however none emerged from the house we were surveying. This outcome was also great for the client because they can now proceed with their proposed building works without posing any conservation risk to bats.

Some obvious-ervations while surveying

If it’s not obvious to you already, bats are really bloody fast so you need to be alert at all times in order to catch them emerging from apertures on a building or tree.

The detectors help of course, because they are directional, so luckily you can get a good idea of the direction if you’re not already facing it by sheer chance. You can this directional feedback to make an educated guess as to where the bat will be (or has been!) and hopefully get a fix. Again, if it wasn’t obvious before, it’s really hard to see in the dark so without the detector as it would be pretty impossible otherwise.

Third; it gets cold at night and you are stood in the same spot for at least 2 hours so wrap up, even if you think it’s a warm evening!

Final obvious observation. If there is no bat activity at all during an emergence survey it can get a tad boring to say the least. Of course, it’s all is made up for when you do hear/see some activity! :)


I thoroughly enjoyed my first foray into emergence surveys. There’s something really peaceful about being around at sunset and watching the bats emerge, fly about and feed. Some people think I’m mad to give up my evenings to observe bat emergences, but I know that I am contributing to the protection of these fascinating mammals and that makes me feel really good about it.

Next time…

I am about to go on a 4-day bat course (got to love the unlimited CPD here!) so check back soon to find out what I thought of it and whether it’s worth you doing it too.


A message from Amy

Thanks for reading this instalment. The next journal blog will be up soon, as I chronicle my journey from ecology zero to surveyor hero. If you’d like an automatic notification of this, follow us on twitter (@superfastsurvey) or sign up to our mailing list below. Please also feel free to share this and leave any comments below.