Bat Surveying in Stages
A few weeks ago, I got the chance to go out at night and help an consultant ecologist do a bat survey. I was excited, for obvious reasons: bats are cool, fun, and they are not and animal I often get to observe out in the wild. I’m a desk-based research student, so I don’t usually roam the British countryside at night. Even more fortunate: I was actually going to be paid to help out! Unbelievable good luck. I was collected by the senior ecologist on the day of the survey at 7:00 PM, with a couple of other students. We set off into the dusk, armed with water bottles, mechanical pencils, and warm waterproof clothing. We were ready to survey bats.
Stage 1: Lost
Our primary ecologist drives around until he reckons we’re in the right place for where he’s been contracted. It’s supposed to be an abandoned farm, and we need to see if bats are using it for anything before any construction happens. He looks around, gets out, and instructs us to stay in the car. We watch, mystified, as he clambers under a locked fence, then back out again. He explains, slightly out of breath, ‘Sometimes our clients aren’t the greatest at remembering to set stuff up for us. I’ve climbed my share of barbed wire fences!’ He laughs. We look at each other, a bit bemused.
Stage 2: Found
It turns out we were actually trying to go into the back of the site by mistake. Our ecologist drives us around to the right place. We set up our equipment: bat sonar detectors (they click audibly and record whenever they register echolocation); a clipboard; and a pencil and a sheet to document whatever we see. ‘Do you guys know what to look for?’ One of the assistants has done a bat survey before, so he explains quickly: look for movement for bats, write down what you see and the time.
Stage 3: Instruction
Our ecologist stations us around the farm building strategically. He explains a bit further, as he’s positioning us, ‘OK folks, you want to keep an eye on the eaves. Bats love to fly around for a bit inside the building and just swoop–‘ here he pauses to illustrate with a swoop motion with his hand — ‘right on out when it’s dark enough. Look for small holes, places where the wall and the roof don’t quite connect, that sort of thing.’ He tells us we’re looking for two main behaviours from the bats. Either they’re performing a direct, straight movement (which he helpfully illustrates with a series of dashes along our record-keeping sheets: Point A —– Point B), or they’re sort of swooping around (this is drawn as a sort of squiggly, loopy line all around the margin of the page). The first is bat commuting behaviour, while the second is the bats feeding, we learn. ‘It can be difficult to tell, sometimes,’ he warns us as we get settled into position. ‘You might not see or hear many bats at all, so don’t get discouraged!’ We carefully train our bat detectors at the building from all our various angles, and prepare ourselves, pencils ready, to begin at 8:45 PM.
Stage 4: Embarking
We stand in absolute silence, eyes glancing on likely-looking gaps, under the eaves, and at flashes of potential movement (mostly tree branches). I listen very closely to my bat detecting device. Aha! A series of clicks! I frantically (yet quietly) look around, and I manage to spot a bat! I carefully annotate the time: 9:05 PM. Type of movement? It looked like commuting. This happens maybe three or four more times over the course of the next two hours. Many times, I hear my bat detector start clicking away, but can’t spot the bat for the life of me. The primary ecologist warned this might happen, and that we ought not fret if it did. ‘Just focus on what you do see,’ he had said. I try to remember his words as I stand, chilly in the July night-time, feeling a bit disheartened.
Stage 5: Post-op
‘So, did you guys have a good time?’ asks the head of our team, as we collect all our belongings and head back out to the car.
‘It was a bit cold, but quite fun,’ offers one student assistant. She is frowning at her sheet. ‘I only saw two bats, and I’m not entirely sure what they were doing.’
Our leader doesn’t seem to mind too much. ‘The bat detectors will have done a lot of the work, and we’ve got in-house analysts who can tell a lot from just looking at what they recorded. It’s helpful to have a couple of pairs of eyes and ears on-site to fill in the blanks.’ He drives us all home, talking about other adventures he’s had and interesting wildlife he’s seen as an ecologist along the way.
In conclusion, it wasn’t quite what I was expecting, but I really enjoyed myself in any case. It was peaceful, standing in the dark, just looking for bats and enjoying the dusk. The people were so fun and friendly to work with, and the work itself so rewarding, knowing I was helping to look out for a protected species.
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