Guild-specific response of bats to motion-triggered LED lighting of bicycle trails

Abstract

Motion-triggered light-emitting diodes (LED) could reduce light pollution; however, its effect on nocturnal animals is poorly known. Here, we investigated how bats respond to the motion-triggered lighting of a bicycle path, an infrastructure that is increasingly being built to support human mobility. We measured the acoustic activity of bats in relation to the activity of LED lights. The responses of bats varied during the night and between functional guilds: Edge-space foraging bats avoided LED lighting, but the response was less clear during early and late night. Open-space foraging and narrow-space foraging bats avoided the LED lighting, especially late at night. The foraging intensity remained relatively stable across the night for bats of all guilds. We conclude that the motion-sensitive LED lighting of bicycle paths induces a guild-specific avoidance response in bats, which could be mitigated by shorter lighting periods.