Action: Use 'warm white' rather than 'cool' LED lights
Key messagesRead our guidance on Key messages before continuing
- We found no studies that evaluated the effects of using ‘warm white’ LED lights rather than ‘cool’ LED lights on bat populations.
‘We found no studies’ means that we have not yet found any studies that have directly evaluated this action during our systematic journal and report searches. Therefore we have been unable to assess whether or not the action is effective or has any harmful impacts. Please get in touch if you know of such a study for this action.
LEDs (light-emitting diodes) are increasingly being used in the lighting industry. It has been suggested that ‘warm white’ LED lights emitting little or no UV component may have less of an impact on bats than ‘cool’ lights emitting blue and UV wavelengths (e.g. Stone et al 2015). Bat vision is more sensitive to light with shorter wavelengths (e.g. Müller et al 2009), and UV lights can attract insects and foraging bats. For similar interventions, see ‘Use UV filters on lights’ and ‘Use red lighting rather than other lighting colours’.
Müller B., Glösmann M., Peichl L., Knop G.C., Hagemann C. & Ammermüller J. (2009) Bat eyes have ultraviolet-sensitive cone photoreceptors. PLOS ONE, 4, e6390.
Stone E.L., Harris S. & Jones G. (2015) Impacts of artificial lighting on bats: a review of challenges and solutions. Mammalian Biology, 80, 213–219.