The Cumbria Bat Group kindly let me come along on a hibernation survey at Easegill Caves in January 2017. We hiked up to Upper and Lower Kirk Caves to see what we could find, then descended using ropes and caving ladders into Link Pot to explore an underground cave network some 15m down.
We found good numbers of myotis species including Daubenton’s, Natterer’s and whiskered/Brandt’s/Alcathoe – these last three are grouped as it’s very difficult to distinguish these three without disturbing the bats. We also found a small number of brown long-eared bats hibernating too.
It’s important to note that disturbing hibernating bats is illegal without a licence from Natural England – this survey was led and supervised by licenced bat workers who ensured that disturbance was kept to a minimum whilst allowing the bats to be identified and counted. If you find a bat in roosting you should take great care not to disturb it especially during the winter as they may rouse from torpor at an inappropriate time and be unable to then survive the winter. If you do find a roosting bat – let your local Bat Group know! More details at the bottom…
The video below shows a summary of the seven hours we spent out in the hills, in just under three minutes!
The following photographs show a few of the hibernating bats we identified on the surveys.
It’s not only bats we found in the caves – plenty of cave spiders and hibernating moths too including herald and tissue moths.
If you would like to get more involved with your local bat group and help out on hibernation surveys such as these, you can find your nearest here. Many thanks to the South Cumbria Bat Group, and Rich Flight in particular, for a great opportunity to explore the caves and see plenty of roosting bats!
We were carrying out a building inspection earlier this week, looking into nooks and crannies to see if we could find bats, or evidence of their presence. To reach these features safely, a cherry-picker was hired to lift us into place. The operator was very friendly and interested in what we were doing. When I asked him to take me up to a crevice above a window, he said;
‘You’ll never get a bat in there’
‘No way… how small are they? I thought they hung up in the rafters?’
The ‘hanging bat’ stereotype is very widespread but really not true of many of bat species in this country. The two horseshoe species will always be found hanging upside-down in the classic pose and some other species will also hang upside down, including the brown long-eared and some of the myotis species. However a number of UK species, including the common pipistrelle – the species you are most likely to see flying in gardens – prefer to roost in crevices where they wedge themselves in quite tightly. Other species falling into the ‘crevice dwelling’ category include the other two pipistrelle species – soprano and Nathusius – the Daubenton’s bat, the larger noctule, serotine and Leisler’s bats, and the rarer woodland dwelling barbastelle bat.
The common pipistrelle bat is often found roosting in crevice-type features in houses, such as beneath lifted hanging tiles or roof tiles, in gaps around windows, in gaps in brickwork or underneath lifted flashing. The gaps they can squeeze into are really very small – 2cm is quite enough for them to get inside.
Last week I was lucky enough to spend a few days climbing trees and inspecting potential roosting features up in Cumbria where we found a common pipistrelle bat roosting in a hollow in a tree limb over a stream. The video quality isn’t fantastic because it is filmed using an endoscope – this invaluable piece of kit is a camera and light mounted on a long flexible ‘snake’ attached to a hand-held screen which you can feed carefully into potential roosting features and look for the bats in places you could never otherwise inspect. Although the quality isn’t great, I think this clip gives a nice insight into the kind of places these bats will choose to roost.
For many more video clips of bats roosting in trees, I would recommend you to check out the Bat Tree Habitat Key page on Facebook.