Artificial light is rightly considered a major social, cultural and economic achievement.
Artificial light is rightly considered a major social, cultural and economic achievement. Yet, artificial light at night is also said to pose a threat to biodiversity, especially affecting nocturnal species in metropolitan areas. It has become clear that the response by wildlife to artificial light at night might vary across species, seasons and lamp types. A study conducted by a team led by the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) sheds new light on how exactly ultraviolet (UV) emitting and non-UV emitting street lamps influence the activity of bats in the Berlin metropolitan area and whether tree cover might mitigate any effect of light pollution. The study is published in the scientific journal “Frontiers in Ecology and Evolution”.
Natural sunlight sets the pace of day and night on our planet. Over millions of years, wildlife and people have adapted to the rhythm of the natural photoperiod. As creatures of daytime, humans have expanded their ecological niche into night-time by inventing and using artificial light. Yet nocturnal animals such as bats may suffer from the detrimental effects of artificial light generated by street lamps, a phenomenon now recognised as light pollution. As it turns out, bat responses to light pollution were complex. “We observed a higher activity of two pipistrelle bat species, the common pipistrelle and Nathusius’ pipistrelle, in areas with high numbers of UV emitting street lamps”, explains Tanja Straka, scientist at the IZW’s Department of Evolutionary Ecology and first author of the study. These opportunistic species may feed on insects that are attracted to UV emitting lamps. “However, all other species were less active at and even repelled by the lamps, irrespective of whether the light they emitted did or did not contain UV light”, adds Straka.
The novelty of this study is that these effects were considered in relation to tree cover. Not only do trees provide bats with shelter during daytime, trees may also provide shade for bats in illuminated areas. “Our goal was to determine whether and how tree cover influences any responses of bats to artificial light”, says Straka.
Read more at Forschungsverbund Berlin
Image: A study conducted by a team led by the Leibniz Institute for Zoo and Wildlife Research (Leibniz-IZW) sheds new light on how exactly ultraviolet (UV) emitting and non-UV emitting street lamps influence the activity of bats in the Berlin metropolitan area and whether tree cover might mitigate any effect of light pollution. (Credit: Christian Giese)
