Street lights provide safety, but a new study found that these structures also disrupt nocturnal pollination by luring moths away from pollinating plants.
This change in the moth's natural behavior can have a devastating effect on their populations as well as the plant species that depend on them.
"Where there are street lights, our research indicates that the moths are being attracted upwards, away from the fields and hedgerows," said study lead and doctoral student Callum Macgregor from the Newcastle University.
A group of researchers from the Newcastle University, Butterfly Conservation charity group and the Natural Environment Research Council's Centre for Ecology & Hydrology in the United Kingdom captured and counted the moths found in farmland areas in Oxfordshire.
They compared the moth numbers found in both brightly lit and dark areas. The research team discovered that ground-based moth numbers in well-lit areas were nearly split in half.
In these brightly lit areas, they discovered that the street lights-level flight activities almost doubled. Notably, the well-lit areas had 25 percent less species compared to the dark farmland areas with no street lights.
Among the captured moths, one in four carried pollen of at least 28 plant species. This suggested that the nearly halved numbers of ground-level moths could affect nighttime pollination.
"Street lighting at night is important for road safety and people's security but our research is just the latest piece of evidence showing the unintended negative effects of street lighting on wildlife," said study co-author Dr. Michael Pocock from the Centre for Ecology & Hydrology.
Past studies have focused on daytime pollinators such as bees and butterflies, overlooking the nighttime pollinators, particularly the roles moths play.
There are currently great concerns over the populations of daytime pollinators. But the recent findings demonstrate that the pollination process is currently facing dual threats — both daytime and nighttime — and these could result in significant consequences.
While the role of street lighting in moth population decline remains uncertain, the new findings suggested that the artificial lighting can affect not just the insects but also the entire ecosystem.
The Natural Environment Research Council funded the study whose findings were published in the Global Change Biology journal on June 1.
Photo: Fernando Butcher | Flickr
