Thursday 2 December 2010

Winter Slumberland

Where do bats go in the winter? Kelly Gunnell looks for the answer in Scotland...


Going looking for bats in the winter seems like a fool’s task. It is common knowledge that bats just disappear at this time of year, to magically appear in the spring time. In this information age where we seem to know the answer to almost everything (or at least can find it in a few clicks); it seems absurd that we still don’t know where bats go to hibernate. The standing assumption is that the bats go to underground sites. Yet they are never found in these areas in the numbers to account for their summer population sizes.
Although, it is a rare thing to find hibernating bats, it is possible. While in Scotland recently for the Scottish Bat Worker’s Conference, I set out with local bat experts, Anne Youngman and John Haddow for a little batty adventure.

Our first stop was Doune Castle, made famous in the film Monty Python and the Holy Grail. This medieval castle near Stirling, is made up of grey stone blocks framing a courtyard, with stunning views of snow-capped hills and golden-leaved woodland. In our search for bats I expected us to go down into some dungeon or dark cellar. But no, we found our first hibernating bats tucked into the crevices of the busy, well-lit, entrance tunnel! Why is it that bats never stick to the rules? Someone should give them a manual….
Peering into the jigsaw puzzle stone cracks, I felt a child-like glee. This was just like hunting for brown furry Easter eggs! We found about 6 pipistrelles in the entrance tunnel and adjoining rooms. But it was in one of the side cellars that we got our biggest surprise. Anne spotted two bats in the high arched ceiling and somehow could tell from that distance that they were not pips. At first, Anne and John thought they could be Daubenton’s but eventually decided that they were Natterers. What a treat!

The next stop on our bat adventure was Aberfoyle Tunnel. This is a disused quarry tunnel that John regularly checks for hibernating bats. With hard-hat, head-lamp and wellies I felt very Indiana Jones wading into the cold dark cave. Even with three people scanning the low ceiling for bats, we still nearly missed our bat. Anne’s sharp eyes spotted the lone brown long-eared hanging crystal like from the grey rock. I was thrilled to see how it tucked its ears under its wings so that only the pointy tragus sticks out. John explained that they keep their long ears under their wings to keep them moist. We didn’t find any other bats in the tunnel; apparently January and February are the best time to find hibernating bats there and even then it will only be about a half dozen.
It was a real privilege to see these few lone bats. Thanks to Anne and John for a great Scottish bat adventure.
In the meantime, the mystery of bats in winter awaits another explorer to unravel its secrets...

Kelly Gunnell
Bats and Built Environment Officer