A study has found increasing light pollution in tropical habitats can damage regeneration of rainforests due to its effect on nocturnal fruit-eating bats.
The study is the first to show that bats avoid feeding in light-polluted areas, according to Phys.org. The research was done by scientists from the German Leibniz Institute for Zoo Wildlife Research Berlin (IZW).
The researchers conducted an experiment in Costa Rica on Sowell's short-tailed bats (Carollia Sowelli). They split the bats up into two sections; bats were either put in the naturally dark area or the area lit up with a sodium street lamp. The bats harvested their fruits, mostly pepper plants and figs, in both sections, according to Science World Report.
The results showed that bats flew into the dark section twice as often as they did in the lit-up section. The bats also harvested twice as much fruit in the dark area, Phys.org reported.
The researchers then conducted a second experiment in which they lit the pepper plants growing in the wild with a street light. They measured the percentage of ripe fruit harvested by the bats in dark areas and areas with street light. The bats harvested 100 percent of the fruit in the dark, but only 78 percent in the lit-up areas, according to Science World Report.
Daniel Lewanzik, first author of the study and PhD student at the IZW, talked about the importance of the "seed rain" defecated by bats, which can be reduced by light pollution.
"In tropical habitats bat-mediated seed dispersal is necessary for the rapid succession of deforested land because few other animals than bats disperse seeds into open habitats," Lewanzik said.
Light pollution is growing in many countries due to the increase in economies and human population, Phys.org reported. As a result, destruction of natural habitats may continue unless appropriate actions are taken.
"The impact of light pollution could be reduced by changes in lighting design and by setting up dark refuges connected by dark corridors for light-sensitive species like bats," Lewanzik said.
