title: Barriers and benefits: implications of artificial night-lighting for the distribution of common bats in Britain and Ireland.
abstract: Artificial lighting is a particular problem for animals active at night. Approximately 69% of mammal species are nocturnal, and one-third of these are bats. Due to their extensive movements-both on a nightly basis to exploit ephemeral food supplies, and during migration between roosts-bats have an unusually high probability of encountering artificial light in the landscape. This paper reviews the impacts of lighting on bats and their prey, exploring the direct and indirect consequences of lighting intensity and spectral composition. In addition, new data from large-scale surveys involving more than 265 000 bat calls at more than 600 locations in two countries are presented, showing that prevalent street-lighting types are not generally linked with increased activity of common and widespread bat species. Such bats, which are important to ecosystem function, are generally considered 'light-attracted' and likely to benefit from the insect congregations that form at lights. Leisler's bat (Nyctalus leisleri) may be an exception, being more frequent in lit than dark transects. For common pipistrelle bats (Pipistrellus pipistrellus), lighting is negatively associated with their distribution on a landscape scale, but there may be local increases in habitats with good tree cover. Research is now needed on the impacts of sky glow and glare for bat navigation, and to explore the implications of lighting for habitat matrix permeability.
authors.affiliation: Hatherly Laboratories, University of Exeter, Prince of Wales Road, Exeter EX4 4PS, UK f.mathews@exeter.ac.uk.
authors.forename: Fiona
authors.initials: F
authors.lastname: Mathews
authors.affiliation: Bat Conservation Ireland, Ulex House, Drumheel, Lisduff, Virginia, Country Cavan, Ireland.
authors.forename: Niamh
authors.initials: N
authors.lastname: Roche
authors.affiliation: Bat Conservation Ireland, Ulex House, Drumheel, Lisduff, Virginia, Country Cavan, Ireland.
authors.forename: Tina
authors.initials: T
authors.lastname: Aughney
authors.affiliation: Centre for Ecology and Conservation, University of Exeter, Penryn Campus, Penryn TR10 9FE, UK.
authors.forename: Nicholas
authors.initials: N
authors.lastname: Jones
authors.affiliation: Hatherly Laboratories, University of Exeter, Prince of Wales Road, Exeter EX4 4PS, UK.
authors.forename: Julie
authors.initials: J
authors.lastname: Day
authors.affiliation: Hatherly Laboratories, University of Exeter, Prince of Wales Road, Exeter EX4 4PS, UK.
authors.forename: James
authors.initials: J
authors.lastname: Baker
authors.affiliation: Hallgarth, Leavening, Malton YO17 9SA, UK.
authors.forename: Steve
authors.initials: S
authors.lastname: Langton
mesh_terms: D000818:Animals; D002685:Chiroptera / Q000502:physiology*; D004455:Echolocation; D004784:Environmental Monitoring; D005247:Feeding Behavior / Q000502:physiology*; D007313:Insecta / Q000502:physiology*; D007494:Ireland; D008029:Lighting / Q000295:instrumentation*; D006113:United Kingdom
keywords: Chiroptera; bats; fragmentation; light; migration; vision