Daubenton's on ice!

From BCT's Scottish Officer, Liz Ferrell, comes a fascinating story of winter bat behaviour:

Graham White, a nature enthusiast, had never seen a Daubenton’s bat before and certainly not during daylight hours! He therefore felt very lucky to see one (on two separate occasions) over the festive period where he lives in Coldstream, the Scottish Borders. Graham told us he had been walking along a section of the River Tweed on the 4^th December. It was south facing and the bank was getting a lot of warmth - even on a very cold day. The old mill weir also meant the river was slow flowing and about a metre deep. The result was like a mirror with not even a ripple on the water. The only movement came from insects which dotted the surface. And then there it was, a Daubenton’s bat flying over the water at one o’clock in the afternoon!
 
By pure chance, on the 7^th January, Graham saw another Daubenton’s. This time 1.5 miles from the River Tweed flying over Hirsel Lake along with the geese, swans and goldeneye he had been watching. The bat flew right next to Graham and for a further two minutes he watched and photographed the bat before it disappeared into the waterside trees. Graham mentions that the most astonishing thing this time around was that the lake was 95% covered in thin ice! The bat of course had found the other 5% unfrozen water (all thanks to some very clumsy geese after they had landed on the lake).
 
It led Graham to ask what exactly the bats were doing – were they drinking, actively foraging, both, or neither! In truth, it is hard to say. It was certainly a very surprising encounter with this little hunter. I think this story just goes to show that we have so much to learn about bats' activities through the winter and perhaps climate change is also going to have its effects. We all hope that these two bats were able to survive the winter.
 
Thank you Graham White for sharing your story and photos!

Have any readers seen anything similar? I'd love to hear about it!