https://www.sciencedaily.com/releases/2019/12/191220150604.htm

The international research team led by experts from the Leibniz-IZW investigated how common noctule bats react to various features of the urban landscape in the larger Berlin metropolitan area, in particular to artificial light at night. They were particularly interested in whether bats use illuminated areas for commuting and foraging or whether they switched to dark habitats.

"We noticed that some bats searched for food in areas with artificial light, especially along watercourses. Overall, however, they prefer the dark areas of the city," says Christian Voigt, head of the Department of Evolutionary Ecology at Leibniz-IZW and first author of the paper. However, bats only hunt at street lights when water bodies or areas with high vegetation cover are nearby. Voigt and his colleagues suspect that many insects are present at these sites when insects are lured by the street lamps at rivers, channels and lakes: "Particularly near water bodies, swarms of insects can be found buzzing around lanterns after they have developed from larval stages into adult insects. Of course, this also attracts some bats who like to take advantage of this rich food supply." In contrast, common noctule bats avoid artificial light when they commute between different feeding areas and their daytime roosts. For commuting, they prefer dark corridors such as forests, unlit city parks or waterways. Some even fly out of the city into the countryside and return before dusk.