The influence of low intensities of light pollution on bat communities in a semi-natural context.

Aurelie Lacoeuilhe,Nathalie Machon,Jean-François Julien,Christian Kerbiriou,Agathe Le Bocq,John Morgan Ratcliffe

doi:10.1371/journal.pone.0103042

Abstract

Anthropogenic light pollution is an increasingly significant issue worldwide. Over the past century, the use of artificial lighting has increased in association with human activity. Artificial lights are suspected to have substantial effects on the ecology of many species, e.g., by producing discontinuities in the territories of nocturnal animals. We analyzed the potential influence of the intensity and type of artificial light on bat activity in a semi-natural landscape in France. We used a species approach, followed by a trait-based approach, to light sensitivity. We also investigated whether the effect of light could be related to foraging traits. We performed acoustic surveys at sites located along a gradient of light intensities to assess the activity of 15 species of bats. We identified 2 functional response groups of species: one group that was light-tolerant and one group that was light-intolerant. Among the species in the latter group that appear to be disadvantaged by lighting conditions, many are rare and threatened in Europe, whereas the species from the former group are better able to thrive in disturbed habitats such as lighted areas and may actually benefit from artificial lighting. Finally, several methods of controlling light pollution are suggested for the conservation of bat communities. Recommendations for light management and the creation of dim-light corridors are proposed; these strategies may play an important role in protecting against the impact of light pollution on nocturnal animals.

Highlights

Anthropogenic light pollution represents a growing global issue, currently affecting nearly 20% of the Earth’s surface and increasing by approximately 6% per year [1]
In the context of global changes, the energy currently allocated to artificial lighting could certainly be used differently to have a lower impact on biodiversity
We reported the numerical results of the GLM and plotted the general additive model (GAM) (Figure 1) (R package mgcv) [30]

Summary

Introduction

Anthropogenic light pollution represents a growing global issue, currently affecting nearly 20% of the Earth’s surface and increasing by approximately 6% per year [1] It may have serious consequences for humans, animals and plants [2]. Lights in cities, along roads or in industrial sites fragment the territories of nocturnal animals [2] According to their ecological traits, bats are expected to be strongly influenced by artificial lighting. Bats that feed on moths, and tolerate artificial light, such as Pipistrellus pipistrellus, may benefit from the amount of prey [5] Species such as Myotis spp., Plecotus auritus and Rhinolophus hipposideros, avoid lighted areas while commuting [6] and foraging [5]. Relatively few studies have focused on the impact of artificial lighting on bats at a community level [5], [8], [4], [9]

Objectives

Methods

Results