This content comes from the 9th European Symposium for the Protection of the Night Sky
Shedding Light on Bat Behaviour—How Street Lights Disturb Commuting Bats
Emma Stone, S. Harris and G. Jones (University of Bristol)
Artificial lighting schemes can damage bat foraging habitat directly, through loss of land and fragmentation, or indirectly by severing commuting routes from roosts, polluting watercourses and foraging habitat. The impact of street lighting on bat activity was tested using experiments along lesser horseshoe bat commuting routes at eight sites across Wales and South West England. Hedgerows were illuminated at a mean of 53 lux using two portable high-pressure sodium street lights. Bat activity was recorded using AnaBat remote acoustic detectors. Repeated-measures analysis of variance (ANOVA) was used to test the effect of experimental treatment on bat activity. Treatment type had a significant effect on bat activity (p 0.01). Contrasts demonstrated that all light treatments were significantly different from controls (p 0.05), demonstrating that high-pressure sodium light has a negative effect on lesser horseshoe bat activity. This study has provided the first empirical evidence of a negative effect of high-pressure sodium lights on commuting horseshoe bats and has significant conservation implications for bat habitat management at sites affected by light pollution. Results from this study will be used to develop evidence based mitigation guidance for bats and lighting in the UK.
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