A couple of nights ago, I was sat watching a building in darkness during a bat survey. Despite the lack of natural light, I was able to see every detail of the gable end on which my camera was trained.
I was using a camcorder with nightshot facility, along with some supplementary infra-red lights which illuminated the whole of one side of the house (albeit covertly, so that only I could see the amazing results).

I started to reflect on how amazing our survey equipment can be. This job enables us as ecologists to use some truly astounding technology.
Minimising disturbance
As someone with poor night vision, I am acutely aware of my limitations when carrying out bat activity surveys (i.e. surveys in darkness, when bats are flying). This is the main reason that we started using cameras with low light sensitivity as a means to improve surveys around 2010, and it has been a constant feature of all our work since then. But we don’t just use infra-red filming at night. This technique is a vitally important tool for use inside dark buildings during daylight hours too, to minimise disturbance when checking roosts. In fact, that is the first reason to cheer infra-red – anything that minimises disturbance to our subject matter is welcome. The picture below shows an image captured in darkness inside a lesser horseshoe bat roost – you can see the bats clearly without the need for torchlight.

Confidence in your work
The difference between viewing in infra-red and viewing with your eyes alone is remarkable. The more you can see clearly, the more confidence you have in yourself and your observations; that is a second reason to cheer infra-red. If you have higher confidence in yourself, it is contagious, and much easier to instil it in others, including your report readers. In the picture below you can see a Daubenton’s bat that is hanging on a vertical wall after it has crawled out from the roof edge above – without this technology, it was so dark that the bat could not be seen at all.

Watching bat behaviour
Infra-red can also enable you to see other aspects of bat activity, such as bat behaviours, which sometimes require a fine level of detailed observation. Reason number three for cheering infra-red, then, is that without it, we understand far less about bat behaviour. Put simply, increased understanding leads to much more effective conservation. The images below show one of our camera set-ups in a disused lime kiln in Lancashire; using a camera meant that we could record details of bat behaviour without any disturbance to the bats themselves. This Natterer’s bat was grooming its wings and tail – if you look closely, you can see the bat’s tongue stretching the tail


As always, if you would like our advice and support for any aspect of your work, including use of infra-red cameras for bat surveys, please get in touch.
If you are involved in a development project, we can provide expert guidance about bats, as well as undertaking bat surveys and assessments.
If you are an ecologist, we offer 1-1 and small group mentoring, as well as formal training, both face to face and via webinars.