Conservation Evidence strives to be as useful to conservationists as possible. Please take our survey to help the team improve our resource.

Providing evidence to improve practice

Individual study: Effects of dimming light-emitting diode street lights on light-opportunistic and light-averse bats in suburban habitats

Published source details

Rowse E.G., Harris S. & Jones G. (2018) Effects of dimming light-emitting diode street lights on light-opportunistic and light-averse bats in suburban habitats. Royal Society Open Science, 5, 180205


This study is summarised as evidence for the intervention(s) shown on the right. The icon shows which synopsis it is relevant to.

Use low intensity lighting Bat Conservation

A replicated, randomized, controlled study in 2015 at 21 road sites in Hertfordshire, UK (Rowse et al. 2018) found that street lights dimmed to an intensity of 25% had higher activity of Myotis spp. but lower activity of common pipistrelles Pipistrellus pipistrellus than street lights dimmed to 50% or left undimmed. A greater number of Myotis spp. passes were recorded at street lights dimmed to 25% than at street lights dimmed to 50% or left undimmed (data reported as statistical model results). Fewer common pipistrelle passes were recorded at street lights dimmed to 25% than at street lights dimmed to 50% or left undimmed. The activity of Myotis spp. and common pipistrelles did not differ between street lights dimmed to 25% and unlit controls. Each of 21 sites had three lighting columns (10 m high lamp posts with neutral light-emitting diode (LED) lights) along a stretch of treelined road. Each of four lighting treatments (controlled using pulse modulation) was applied for two consecutive nights/site in May–August 2015: 0% (unlit), 25% (average 11 lux), 50% (average 20 lux), undimmed (average 36 lux). Bat activity was recorded with a bat detector attached to the middle lighting column.

(Summarised by Anna Berthinussen)