NWT East Wretham Heath is not only important for rare Breckland plants and insects, but also for its historical roles as part of Britain’s war effort. A number of buildings and bunkers can be found dotted around the reserve. These remnants of the Heath’s former life as an airfield during the Second World War are an important reminder of the reserve’s and our own history. The buildings are not obtrusive; over the years they have turned from harsh military buildings into valuable habitats, supporting a range of flora and fauna. However, NWT reserves staff have made minor alterations to one bunker, to create a bat hibernaculum. Ten of the UK’s 14 bat species have been recorded in the Brecks, and research suggests that artificial structures are becoming increasingly important as hibernation sites for several species.
The transformation from air raid shelter to bat bunker involved creating artificial bat niches in the bunker to provide roosting habitat. The floor of the bunker was covered with sand and gravel which will help maintain humidity. Temperature and humidity are important factors in a bat hibernaculum, along with darkness and lack of disturbance. An escape hatch was blocked to prevent draft, and the main entrance covered with just a small gap to allow bat access. These simple changes could provide a valuable habitat for species such as brown long-eared, Daubenton, natterer’s and Barbastelle bats.