The Impact of Light Pollution on Bats Varies According to Foraging Guild and Habitat Context

We review how different bat guilds respond to artificial light at night (ALAN) and assess how the impacts can vary according to ecological context. All studied European species respond negatively to ALAN close to roosts and drinking sites, and the impacts occur across a wide range of light colors and intensities. Most bat species are sensitive to ALAN when commuting and foraging. Although narrow-space-foraging bat species consistently avoid ALAN when foraging, open and edge-space-foraging species may exploit insects lured by ALAN. Therefore, ALAN acts as an environmental filter on bat assemblages. Considering the detrimental effect of ALAN on insects, we conclude that ALAN probably has negative impacts on all bat species, even on those foraging at streetlights. The sprawl of ALAN may be a key factor driving the decline of bat diversity globally, and the current trajectory of increasing ALAN is therefore of considerable concern for bat conservation.

Automated summary

Research indicates that different bat guilds respond to artificial light at night (ALAN) in various ways, with impacts depending on ecological context. Most bat species exhibit negative responses to ALAN near roosts and drinking sites, while some species may exploit insects attracted by ALAN. Overall, the detrimental effects of ALAN on insects may have negative impacts on all bat species.