Since I last wrote a post for the blog the bat season has begun, but it's come as more a damp thud, rather than the exciting start we were planning. This is down to the weather which has been colder, wetter and windier than we've experienced at this time in the last few years. Unfavourable weather prevents us from getting out to survey, and also when it occurs over a longer period can have a notable negative impact on the bats, which is particularly reflected in the number of juveniles for the year and perhaps the lower weights of some of the bats we've been seeing.
To read a brief report of the surveys so far, click on.
So far we have completed five surveys, when we would have ideally hoped to have done several more and to have already radio tagged some bats, but this hasn't been feasible. Our first survey was at the end of the May heatwave and if you've been following our twitter feed you'll know that we caught fourteen bats of five different species, an auspicious start that we have thus far failed to match. The following weekend we visited another new woodland but having sited and set up the traps the rain set in and we had to pack up and clear off before even starting the survey. We revisited the site a week later and were able to complete a survey, although the wind was blowing more than is ideal. On this occasion the gentle stream that we had crossed the previous week had become a much more significant obstacle and only three bats were encountered - none of them Bechstein's.
The following night, we returned to a wood that had been surveyed last year. We were intrigued by the mix of species found, as well as the presence of both male and non-breeding female Bechstein's bats. We plan to visit this woodland twice this year and on our first visit we were accompanied by a producer and director from a production company who will be filming for the BBC's 'The One Show' when we return later in the season. On this survey the wood was very quiet, with few bats flying and only two brown long-eared bats coming into the traps. This was sufficient for the film-makers requirements but we were disappointed with the apparent lack of bats in what has previously been a very promising site.
The next survey followed a fortnight later, due to high winds and rain during the intervening time. Despite being windier than we would have liked, this survey marked a minor change in our fortunes with several bats gracing our traps. We caught some brown long-eared bats, and it was interesting to note that despite the difficult conditions they were noticeably pregnant - and so were quickly released. However, the we were particularly encouraged to catch a Bechstein's bat, a male, and the first we have seen this year. It was nice to get another glimpse at the species that has inspired all our efforts.
Our most recent survey thus far this year followed soon after the above, on a warm and humid night (unusually for this year). On this occasion we caught bats of a total of four species, not counting a pipistrelle that was sitting on top of the trap bag and flew off as I tried to pick it up. In addition to brown long-eared bats, Natterer's and a suspected Brandt's we caught another Bechstein's bat. Particular excitement ensued as this individual was female, however it did not appear to be pregnant and its weight supported this conclusion, and so we recorded it as non-breeding - nonetheless a promising record.
We will continue to fit surveys in when the weather suits, and although a little disheartening it is something that is beyond our control. This approach is currently tempered with caution as we enter birthing period, we prefer to avoid disturbance to females around this time, and this further constrains what we can do. However, there is still plenty of the season remaining and it will certainly be interesting to see what effects this strange weather has, although some may not become clear until later.
Welcome to the Bernwood Forest Bechstein's Project Blog! Following the discovery of breeding Bechstein's in Buckinghamshire during a National Bat Conservation Trust survey, this subsequent project was conceived by Chris Damant, Jo Hodgkins and Toby Thorne to follow up and find out more. See below for updates on the blog and follow our Twitter feed @bechsteins.
All work is conducted under license from Natural England. All British Bats are protected by law.
The Bernwood Forest Bechstein's Project is a project of the North Bucks Bat Group.