Major Listening Operation to Protect Bats
Of the more than 1,200 bat species worldwide, 25 live in Germany. They bear names such as the Greater and Lesser Horseshoe Bat, the Mouse-eared Bat, and the Barbastelle. All species living among us are threatened and appear on the Red List of Endangered Mammals.
Bats are fascinating animals: they «hear» the world through their oversized ears, which function like satellite dishes. They navigate their habitat using a form of ultrasonic echolocation: «hearing-images» are created when the mammals recapture their own ultrasonic calls as echoes in order to locate their surroundings. Using bat detectors – also known as listening boxes – the calls of these night-time creatures can be recorded without disturbing them. Special computer programmes then convert the calls, allowing individual species to be identified.
They live right among us, yet mostly remain invisible: bats don't leave their roosts in cellars, attics, and cemeteries until dusk. They then flutter in their thousands through Hamburg, Leipzig, or Munich. Berlin is widely regarded as Europe's bat capital: 18 of the 25 species found in Germany are at home there. In the Spandau Citadel alone, more than 10,000 animals hibernate every year.
All 25 species, from the tiny Barbastelle to the Brown Long-eared Bat, are strictly protected in Germany. However, this status alone is not sufficient to ensure the survival of these nocturnal hunters. The dramatic decline of insects – the exclusive food source of all German bats – poses a serious threat to these small mammals. Ironically, it is human metropolises that offer a refuge for many species.
The activities are part of a nationwide project on the barbastelle bat, coordinated by the FLEDERMAUS Foundation. The aim is to document the occurrence of the barbastelle bat in Germany and to develop guidelines for the conservation and management of its woodland habitats. The reason for this scientific surveillance operation is the massive decline of the barbastelle bat, for which Germany bears a particular responsibility. »Using the information we obtain from the batcorders, we can determine the species spectrum and distribution of the animals on the areas managed by the Deutsche Wildtier Stiftung», says Sebastian Brackhane, project leader for bat conservation at the Deutsche Wildtier Stiftung. And there is more: «We also aim to investigate whether and how the species spectrum of bats in forests without forestry use differs from that in commercial forests. This will also allow conservation measures to be developed more precisely», says Brackhane.
«In monotonous forests with few old and dead trees, bats lack a place to raise their young», explains Brackhane. «Female bats are giving birth to their young right now in summer. They support each other in raising their offspring. There are maternity roosts where the young live together like in a nursery. On the site in Rechlin, old trees with loose bark and cavities are particularly suitable for this purpose», says the project leader of the Deutsche Wildtier Stiftung.
