1. Artificial light may change flight patterns of bats near bridges along urban waterways
- Author
-
Clémentine Azam, Kévin Barré, R. Kiri Ing, Dany Lapostolle, Kamiel Spoelstra, I. Le Viol, Christian Kerbiriou, Georges Zissis, Yves Bas, Samuel Challéat, Centre d'Ecologie et des Sciences de la COnservation (CESCO), Muséum national d'Histoire naturelle (MNHN)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Animal Ecology (NIOO-KNAW), Netherlands Institute of Ecology (NIOO-KNAW), Géographie de l'environnement (GEODE), Université Toulouse - Jean Jaurès (UT2J)-Centre National de la Recherche Scientifique (CNRS), Institut Langevin - Ondes et Images (UMR7587) (IL), Ecole Superieure de Physique et de Chimie Industrielles de la Ville de Paris (ESPCI Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), UNION INTERNATIONALE POUR LA CONSERVATION DE LA NATURE (UICN), UICN, Lumière et Matière (LAPLACE-LM), LAboratoire PLasma et Conversion d'Energie (LAPLACE), Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université Fédérale Toulouse Midi-Pyrénées-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Théoriser et modéliser pour aménager (UMR 6049) (ThéMA), Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC)-Centre National de la Recherche Scientifique (CNRS)-Université de Bourgogne (UB), and Animal Ecology (AnE)
- Subjects
0106 biological sciences ,river ,Foraging ,Biodiversity ,Light pollution ,Artificial light ,Nocturnal ,010603 evolutionary biology ,01 natural sciences ,microphone array ,ecological corridor ,Chiroptera ,Ecosystem ,Relative species abundance ,Nature and Landscape Conservation ,flight behaviour ,Ecology ,010604 marine biology & hydrobiology ,acoustic localisation ,light pollution ,Plan_S-Compliant_NO ,15. Life on land ,rivers ,Geography ,Habitat ,international ,[SDE]Environmental Sciences ,[SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology - Abstract
International audience; Artificial light at night (ALAN) is considered as a major threat to biodiversity, especially to nocturnal species, as it reduces availability, quality and functionality of habitats. However, its effects on the way species use landscape elements such as rivers are still largely understudied, especially the effect of crossing infrastructure lighting on bridges. These elements are nevertheless key commuting and foraging habitats in heavily urbanised landscapes for several taxa such as bats that are particularly affected by ALAN. We studied the effects of the illumination of facades and undersides of bridges on the relative abundance of pipistrelle bats, on their 3D distribution and their behavioural response (i.e. flight speed) close to bridges. We set-up an innovative approach based on a microphone-array to reconstruct positions and flight trajectories in 3D. We studied the effect of lighting on bats in the close proximity of six similar bridges, mostly differentiated by the presence or absence of lighting (3 lit and 3 unlit). All bridges cross the same waterway, within a uniformly and highly urbanized agglomeration (Toulouse, France). We found that bat activity was 1.7 times lower in lit sites. Bats tended to keep a larger distance, and to fly faster close to illuminated bridges. These results suggest that bridge lighting strongly reduces habitat availability and likely connectivity for bats. In that case, results call for switching off the illumination of such bridges crossing riverine ecosystems to preserve their functionality as habitats and corridors for bats.
- Published
- 2020