title: The impacts of new street light technologies: experimentally testing the effects on bats of changing from low-pressure sodium to white metal halide.
abstract: Artificial light at night is a major feature of anthropogenic global change and is increasingly recognized as affecting biodiversity, often negatively. On a global scale, newer technology white lights are replacing orange sodium lights to reduce energy waste. In 2009, Cornwall County Council (UK) commenced replacement of existing low-pressure sodium (LPS) high intensity discharge (HID) street lights with new Phillips CosmoPolis white ceramic metal halide street lights to reduce energy wastage. This changeover provided a unique collaborative opportunity to implement a before-after-control-impact field experiment to investigate the ecological effects of newly installed broad spectrum light technologies. Activity of the bat species Pipistrellus pipistrellus, P. pygmaeus and Nyctalus/Eptesicus spp. was significantly higher at metal halide than LPS lights, as found in other studies of bat activity at old technology (i.e. mercury vapour) white light types. No significant difference was found in feeding attempts per bat pass between light types, though more passes overall were recorded at metal halide lights. Species-specific attraction of bats to the metal halide lights could have cascading effects at lower trophic levels. We highlight the need for further research on possible ecosystem-level effects of light technologies before they are installed on a wide scale.
authors.affiliation: School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK emma.stone@bristol.ac.uk.
authors.forename: Emma Louise
authors.initials: EL
authors.lastname: Stone
authors.affiliation: School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK.
authors.forename: Andrew
authors.initials: A
authors.lastname: Wakefield
authors.affiliation: School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK.
authors.forename: Stephen
authors.initials: S
authors.lastname: Harris
authors.affiliation: School of Biological Sciences, University of Bristol, Life Sciences Building, 24 Tyndall Avenue, Bristol BS8 1TQ, UK.
authors.forename: Gareth
authors.initials: G
authors.lastname: Jones
mesh_terms: D000818:Animals; D002685:Chiroptera / Q000502:physiology*; D004784:Environmental Monitoring; D004787:Environmental Pollution; D005247:Feeding Behavior / Q000528:radiation effects*; D007313:Insecta / Q000502:physiology / Q000528:radiation effects*; D008029:Lighting / Q000295:instrumentation*; D013045:Species Specificity
keywords: Philips CosmoPolis lights; artificial lighting; ecosystem-level effects; light pollution