A few clips from a dawn survey of a large maternity roost I have been working on in Fort Augustus. I have been keen to trial some thermal imagery to see how they perform with bats and this roost seemed like a good test. Working with the team at Red Current we identified the FLIR E60 as the best unit to try.

The bats are clearly visible, but were not glowing as hot as I expected. The odd one comes back out of the roost and is significantly hotter than the flying ones, so I assume that they are fairly well insulated. The temperature during the night dropped and at the time of this was surprisingly cold at around 4 degrees C. Possibly because of this drop in temperature overnight the bats were entering the roost relatively early with all bats (about 1500) in the roost 30 mins before sunrise. The small area of hotter roof is the installed bat access slate, required under licence but not utilised as we kept the existing entrance.