Light pollution, a growing environmental issue, significantly impacts nocturnal animals, especially insects like moths. The widespread use of artificial lighting at night—such as streetlights and illuminated buildings—has caused major changes in ecosystems, disrupting the natural behavior of many species. Moths, which have already been experiencing dramatic population declines, are increasingly affected by light pollution, not just within the reach of artificial lights, but in areas far beyond.
A recent study led by researchers from Julius-Maximilians-Universität (JMU) Würzburg in Germany, in cooperation with Berlin and Providence (USA), reveals that light pollution disrupts moths’ flight behavior even outside the illuminated areas. The study, published in the scientific journal PNAS, used radar tracking to monitor moths’ flight paths. This cutting-edge method allowed scientists to observe their movements over distances of up to one kilometer.
The results were unexpected: only 4% of the moths flew directly toward the streetlights. Instead, most showed erratic and disoriented flight patterns far beyond the lit areas. These findings challenge the previous assumption that light pollution primarily draws insects directly to light sources. The study shows that the impact of light pollution is much more widespread, affecting moths’ ability to navigate even in darker zones.
One of the more intriguing discoveries was the interaction between artificial light and the moon’s position in the sky. Researchers observed that moths’ disorientation varied depending on whether the moon was above or below the horizon. This interaction is not yet fully understood but suggests a complex relationship between natural and artificial light sources, which will likely be explored further in future studies. Moths play an essential role in ecosystems, including pollination and serving as prey for other animals. Understanding and mitigating light pollution is crucial for preserving biodiversity and maintaining the balance of ecosystems in the face of modern urbanization.
(Image by Elise Vermeer from Unsplash)
DAAD-Gastprofessorin at Julius-Maximilians-Universität Würzburg