Brazil natural landscape degradation drives toxic metal buildup in bats

Bats play a key role in maintaining the health of forest ecosystems as pollinators, seed dispersers and insect pest controllers. But according to new research, bats and the ecosystem services they offer are under threat in Brazil’s heavily fragmented Atlantic Forest biome, where natural lands have been largely converted for agriculture and mining, degradation that is increasing wildlife exposure to toxic heavy metals. Scientists at Brazil’s Santa Cruz State University plucked hair samples from bats in the state of Bahia across a patchwork of landscapes — including cattle pasture, eucalyptus and coffee monocultures and cacao agroforest — then tested them for three metals: lead, manganese and copper. “We found that bats living in areas where the landscape is dominated by intensive agriculture or grasslands have higher levels of toxic metals, particularly lead and manganese,” says Julián Barillaro, the study leader and a conservation ecology researcher at Santa Cruz State University. This, he says, is likely due to use of agrochemicals and leaded fuel. Reduced natural habitat also likely increased exposure. Other factors, such as bat species and sex, didn’t affect bioaccumulation, leading the authors to believe that the bats came into direct contact with these heavy metals by resting on contaminated leaves or trees and then grooming. The exposure levels within different monocultures requires further study, Barrilaro says, as some bat species are highly mobile and could be moving from crop to crop. By comparison, the researchers found that bats in cacao agroforestry areas with higher natural forest cover had…This article was originally published on Mongabay