Thermal for Bat Surveys

Thermal for Bat Surveys

Thermal imager use for bat surveys is another important area of interest that we are seeing an increasing demand for. As prices of thermal units has come down and they have become more accessible, people are seeing how useful they are for watching and monitoring these tiny fast flying mammals.

By the very nature of bats and their nocturnal activities they have proven tricky at times to study. From the curious homeowner who sits out at dusk counting emerging bats, to professionals checking roof spaces and trees before building work – thermal imaging is helping save time, money and, more importantly, help protect bats that would have been overlooked previously.

Due to the fast movements of bats on the wing, and their small size we always recommend units with higher sensor rate to give you the most accurate information. This does, however depend on the situation they are being used in.


What size sensor do you need?

Tradesmen who work in lofts have to check for bat activity before picking up their tools. Entry level units with small 320x240 sensors would be perfectly adequate for speeding up their prework checks. These units work well in small areas, and will happily show up a roosting colony as well as individuals. They are also usually a neat size that fits into a pocket well, and the lower battery life wouldn’t be an issue as they wouldn’t be used for lengthy amounts of time. Units like the Pulsar Axion XM30F tick all these boxes at an affordable price.

The slightly bigger 384x288 sensor in the Pulsar Axion XQ35 Pro is used for bat surveys but you would be struggle with clarity at further distances, particularly with smaller species. These are great for wildlife enthusiasts who would like to watch bats flying in open spaces but species ID and exact numbers are not important. Another great option for hobbyists is the Zeiss DTI 3 which offer an ergonomic design which can be used in either hand.

Ecologists require the next jump up in sensor size to be able to survey at further distances. We would suggest a minimum of a 640x480 sensor for this. The new Pulsar Telos XP50, or the Zeiss DTI 4 & 6 series would give the clarity required as well as extended battery life needed for professional use. If a physically smaller device is required, and a shorter battery life is no problem then the Pulsar Axion XG35 gives you a great sensor at a lower price, built in their small compact body. I am no bat expert but I am assured by those that are that these units can allow positive ID of species (conditions and environment depending). The Pulsar Merger series are binocular style thermals with two eyepieces, not one. These are great when viewing for longer periods of time as they are really comfortable to hold. They also can come with the massive 1024x768 XL sensor – the image with these is truly astounding.

The footage below was filmed using the Pulsar Merger XL50 


Use in the field 

Most thermal units are tripod mountable and this is a great way of counting numbers via video. Once fixed pointing at an emergence point, or in a gap between buildings, you can set the video to record and sit back and wait. After you have finished recording you can download the footage and watch back on your computer screen. You can slow down or pause the footage as you go, making sure every individual is recorded to give you the most accurate data possible. This was the set up used to record the video above.

Pulsar Merger XL50 looking for bats

Many other photography mounts are also great for thermals. I find my Vortex Car Window Mount very useful. Pulsar have their own range of accessories too - the tree mount being my favorite for remote places. We have a range of these accessories listed in our shop.


Further reading

For anyone serious about bat conservation it is worth reading Thermal Imaging: Bat Survey Guidelines written by Dr Kayleigh Fawcett. They have been published in association with the Bat Conservation Trust and they can be found here 

Like all digital technology however, the world of thermal moves very quickly. Over time newer units will appear and prices will fall. We always stock the latest units and spend time using each unit in the field. We will always give our honest advice on which thermal works best in a variety of situations.


If you have any questions over what unit would suit your needs best then please get in touch

 Thanks for reading



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