The effect of artificial light at night on nocturnal mammals

How do nocturnal mammals, such as bats, respond to artificial light at night? Which solutions can we offer to mitigate or compensate the potentially detrimental effects of light pollution on bats?


Each year, the relative proportion of the earth surface illuminated by artificial light at night is increasing by 2% (Kyba et al. 2017). Since many of our wildlife species are nocturnal, they are exposed to increasing level of artifical illumination in their habitats. Additionally, we are facing a highly dynamic transition of outooor lighting schemes (e.g. LED), which happens without knowing how these new light types might impact plants, animal and whole ecosystems..


Bats are obligat nocturnal mammals, which have evolved over millions of years to cope with a life in darkness (Voigt & Lewanzik 2012, Roeleke et al. 2018). Bats use echolocation to orientate at night and to find food. Among native bats some are exploiting insects at street lanterns in an opportunistic way, others respond very aversive towards artificial light at night.


We examine on the individual, population and landscape level how bats react to artificial light at night. We are doing this by studying bats in different context, for example we observe bats how they respond to artificial light when emerging from their roost (Straka et al. 2020) or when hunting or commuting (Lewanzik & Voigt 2017, Straka et al. 2019, Voigt et al. 2019).


Conservation related findings are communicated via workshops, conferences and guidelines (Voigt et al. 2018), to specific stakeholders and to the broad public.



Our collaborators in Berlin and Brandenburg help us in conducting field work and in analyzing the spatio-teporal movements of bats.

Fig. 1: Nathusius bat flying in front of a street lamp ((c) Christian Giese)

Funding: BiBS, WTImpact, RTG Biomove

Leibniz IZW team: 

PD Dr. Christian Voigt (Dept EvolEcol)

Dr. Daniel Lewanzik (Dept Ecol Dyn)

Prof. Dr. Stephanie Kramer-Schadt (Dept Ecol Dyn)

Consortium partners:

Prof Dr Florian Jeltsch (University of Potsdam)

Dr. Ulrike Schlägel (University of Potsdam)

Dr. Sascha Buchholz (Techbical University of Berlin)

Dr. Tanja Straka (ehem. Dept Evol Ecol, jetzt Technical University of Berlin)

Uwe Hoffmeister, Tobias Teige and Torsten Blohm (Berlin and Brandenburg)

Selected publications:

Straka, T.N., ...., Voigt, C.C. (2020): The effect of cave illumination on bats. Global Ecology and Conservation 21: e00808.


Voigt, C.C., Scholl, J., Bauer, J., ..., Kramer-Schadt, S., Gras, P.(2019): Movement responses of common noctule bats to the illuminated urban landscape. Landscape Ecology. doi 10.1007/s10980-019-00942-4


Straka, T., Wolf, M., Gras, P., .., Voigt, C.C. (2019): Tree cover mediates the effect of artificial light at night on urban bats. Frontiers in Ecology and Evolution: doi 10.3399/fevo.2019.00091


Voigt, C.C., ..., Fritze, M., ..., Lewanzik, D. et al. (2018): Guidelines for consideration of bats in lighting projects. UNEP/EUROBATS publication series #8.


Roeleke, M., ...,, Voigt, C.C. (2018): Aerial-hawking bats adjust their use of space to the lunar cycle. Movement Ecology 6:11. 


Lewanzik, D., Voigt, C.C. (2017): Transition from conventional to LED street lighting changes activity of urban bats. Journal of Applied Ecology 54: 264-271.


Voigt CC, Lewanzik L (2011): Trappend in the darkness fo the night: Thermal and energetic constraints of daylight flight in bats. Proceedigs of the Royal Society of London B, 278, 2311-2317. 

Fig. 2: Predicted foraging areas (marked blue) for common noctule bats in the illuminated landscape of the Berlin metropolitan area. Large areas of Berlin seem to be unsuitable for common noctules as hunting grounds. This is largely driven by impervious surfaces  and artificial light at night.