Bat walk 2023

As twilight drew closer on Goonhilly Downs on 20 September, we were treated to a fount of knowledge about bats from experts Paul Diamond and Tony Atkinson (part of our 2023 conference fringe events).

Image: Nick Pearce-Gowildcam

We learnt that there are at least 18 species of bat recognised in the UK, including several types of pipistrelle. Some species have been adversely affected by street lights, whereas other species do not seem to be affected.

Compared to other counties in the UK, Cornwall does not have a large bat population. However we –along with south west England and Wales – do have the Greater and the Lesser Horseshoe Bats, which choose to rest in temperatures warmer than 10 degrees centigrade, so they may go underground in cellars and railway tunnels.

Image: Nick Pearce-Gowildcam

In the winter bats need a stable temperature in order to hibernate. However, it’s thought that true hibernation does not actually occur – rather, the bats adopt a state of torpor when the body temperature assumes the ambient temperature. In order to achieve and survive torpor, they need somewhere moist so they don’t dehydrate. They may move about between about ten roosts in the winter, and are supported by being a congregation.

Congregations of bats are precious. Our changing weather and extreme temperatures are a challenge for British bats. For example, they are not used to modifying their behaviour to survive long hot, dry summers.

Image: Nick Pearce-Gowildcam

We can detect and identify bats using bat detectors, which pick up the echolocation ultrasound signals emitted by the bat and convert these to audible frequencies.

Walking along moonlit paths on Goonhilly Downs, we heard pipistrelle and some type of myotis bat. Paul’s detector picked up a noctule bat.

Anyone interested in the formation of a local bat group, please get in touch: wildlifegroundswell@gmail.com