BSG partner Dr Peter Shepherd has been closely involved with a bat box monitoring scheme in Sherwood Forest over the last 16 years. Since monitoring began, the species recorded have regularly included noctule, Leisler’s, common and soprano pipistrelles , with occasional brown long-eared bat and whiskered/Brandt’s bats being recorded.
The boxes are checked twice a year in spring and autumn. Bat numbers have tended to be higher in the autumn due to the presence of harems (particularly of Pipistrelle species and Leisler’s bat). Over the last couple of years, however, a maternity colony of Leisler’s bats has taken up residence in several adjacent standard wooden bat boxes. These boxes are quite small for the number of females using them (estimated to be between 20 and 30 bats) and there is quite a bit of jostling on warmer days resulting in the lid of the box jumping up and down on occasion and a series of social calls being emitted. Trainee bat workers are often told that you can hear these characteristic social calls as they are within human hearing range and are told to listen out for them when doing surveys, but rarely are we able to provide a recording to demonstrate just what a chittering bat sounds like. The attached video clips capture the characteristic chittering and squeaking clearly and hopefully will be of interest to those trainee bat workers who have not heard the sound before. It is always a pleasure to hear bats in roosts exhibiting this behaviour and this year the females at this box were in fine voice chittering away for some time.
Please note that you may have to turn up the volume on your audio equipment to be able to hear the bats.
For more information on the project, please contact Peter Shepherd.