1st February 2014
My latest target species from my 30 Interesting Things list was Natterer's Bat, a fairly common bat that I hadn't seen before. Whilst I may have been able to find one by roaming around in the evenings with a bat detector, I had joined the Norwich Bat Group and knew that they sometimes allowed members to come on Hibernaculum visits. As it happened the old Lime Kiln at Whitlingham often has Natterer's Bats over the winter, so that seemed a good bet.
Earlier in the week Jim (who is a committee member of the Norwich Bat Group) had let me know that there was going to be visit on Saturday. I had planned to go out with Cathy, but she very supportively said that I should go and look for bats instead. As a result of this, I met Richard Moores and four other members of the bat group at Whitlingham, and we headed to the Lime Kiln in Whitlingham Woods.
I had been told that Natterer's Bat should be certain here, but things don't always go to plan, and the keys we had been given to unlock the kiln wouldn't work. Whilst we waited for another set to be brought we kept an eye out for birds moving through, and these included a Nuthatch and Marsh Tit. When a member of the Broads Authority turned up with another set, these didn't work either, with the suspicion that someone had tampered with the lock, making it unusable. Leaving him to inspect the lock, we headed back along Whitlingham Lane to Trowse Meadow, where there is a second bat hibernaculum in an old tunnel.
I was now less confident of seeing Natterer's - on the last check this tunnel only held a single Brown Long-eared Bat. With the padlock working first time we squeezed through the narrow entrance and into the tunnel. Several hibernating Peacock butterflies and Herald moths were on the ceiling as we moved further in. I spotted some bat bricks and found our first bat of the day. It was a Myotis sp, and having not seen any of them close up I guessed at the commonest one, Daubenton's. Everyone had a look, and opinion was split, but the majority thought it could well be a Natterer's. Close by in another bat brick was a Brown Long-eared Bat, and then at the end of the tunnel was a definite Daubenton's Bat. With this to compare with we looked again at the debated Myotis, and everyone agreed that it was indeed a Natterer's Bat. Success! Not wanting to disturb the bats I didn't take any photos, so you'll have to make do with this "artist's" impression.
Many thanks to Richard and to the Norwich Bat Group for allowing me to come on the hibernaculum check. It is important to note that all British bats are protected by law and roost sites shouldn't be visited without a licensed bat surveyor . For more information about the Norwich Bat Group and their projects, check out their website: http://norwichbatgroup.org.uk/index.html