Minding the gap…. City bats won’t fly through bright spaces

Researchers at Lancaster University have discovered that bats living in a city are less likely to move from tree to tree in brightly lit areas. Their To maintain high biodiversity in cities, wildlife must be able to move between patches of habitat, which are often separated by paved surfaces, buildings and roads. The bats studied in this experiment emerge in the evening from their roosts, often within residential housing areas, to feed on small insects in gardens, streams and other green spaces. To reach these feeding areas they often "commute" along lines of trees, which are thought to provide protection from predators and high winds. Gemma Davies, of Lancaster Environment Centre, along with colleagues from the University of Birmingham, studied the impact of artificial light on the bat species, Pipistrellus pipistrellus (the Common pipistrelle), which is found in many parts of UK cities. The team wanted to find out whether the bats' crossing behaviour was affected by the distance between trees and the brightness of lighting within the intervening gap. They found that the bats crossed via the darker parts of the gaps, but with sufficient lighting these gaps became barriers to movement.