UW-Madison researchers have added credence to the notion that bats are the mosquito-hater’s friend. Using samples of bat fecal matter, or guano, they proved the animals eat many different species of Wisconsin’s unofficial state pest.
“While this study doesn’t tell us whether bats actually suppress mosquito populations, it does create a strong case for re-evaluating their potential for mosquito control through additional research,” said Amy Wray, a doctoral student in the Department of Forest and Wildlife Ecology.
The study’s results were published in the Journal of Mammalogy.
Previous studies claimed a bat could consume 10 mosquitoes per minute, but the results were from a controlled-enclosure experiment.
The UW-Madison research team used volunteers to collect bat feces in 2014 from areas beneath a dozen little brown bat and 10 big brown bat maternity roosts in farm and forest land across the state.
DNA was extracted from the samples to screen for mosquitoes using new techniques that analyze insectivore diets — or the diets of animals that eat insects, such as bats.
The results showed at least one mosquito in all of the little brown bat sites and in 60 percent of the big brown bat sites.
The bats also ate a wide variety of mosquitoes, including those transmitting West Nile Virus.
“This study is the first step in revisiting important questions regarding the bat’s role as a mosquito-control agent, which could have implications for human health,” said Claudio Gratton, professor of entomology at UW-Madison and co-author of the study.
Bat populations have declined because of a number of factors, including white-nose syndrome in North America, so the researchers feel it’s important to re-examine the bat as a mosquito-control agent and to emphasize the need to preserve the animal.
“Bat declines resulting from white-nose syndrome and other factors may compromise potential mosquito suppression, but they also provide opportunities to test the hypothesis that bats limit mosquitoes through a natural experiment,” said Zach Peery, a UW-Madison professor of forest and wildlife ecology.