Bat gets green light

LED street lights on canal in Assen are efficient and environmentally friendly

Green LED lighting is more efficient than the traditional fluorescent street lights and is probably more environmentally friendly. This is good news for municipalities that want to switch to sustainable street lighting.

In the late summer of 2009, Tijs Glazenborg, an Ecology student, counted the numbers of Daubenton's Bats that passed a canal in Assen, the Afwateringskanaal, at night. The canal is an important flight route and foraging range for various species of bats.

Glazenborg compared three situations: while fluorescent lighting, green LED lighting and no lighting. When green LED lights were used, he counted approximately the same amount of bats as during the undisturbed, unlighted situation. There are indications that intensive white light attracts bats and thus disturbs their natural behaviour.

In the interests of public safety, the municipality of Assen wants to install street lighting in the recreational area surrounding the canal, but at the same time they want to disturb the local habitat as little as possible. As humans can see fine with green light at night, green LED lighting seems to be the best choice.

The research was supervised by Prof. Joost Tinbergen, animal ecologist at the University of Groningen, with the cooperation of the Drenthe Bat Working Group (vleermuiswerkgroep Drenthe) and Bureau BügelHajema of Assen. Karin Ree of the University of Groningen Science Shop coordinated the project.

Note for the press

Councillor Alex Langius of the municipality of Assen was officially presented the report on Monday 1 March at the town hall (address: Noordersingel 33, Assen).