Bats save the agricultural industry an estimated $3 billion a year, yet they are among the most overlooked animals in North America, according to a new analysis published this week in Science.


And they are increasingly under threat by wind farms and disease.

"Bats eat tremendous quantities of flying pest insects, so the loss of bats is likely to have long-term effects on agricultural and ecological systems," said Justin Boyles, a researcher with the University of Pretoria and the lead author of the study.

A single little brown bat, which has a body no bigger than your thumb, can eat 4 to 8 grams (the weight of about a grape or two) of insects each night. Seems small – but it adds up fast. The loss of the one million bats in the Northeast has probably resulted in between 660 and 1320 metric tons of insects no longer being eaten each year by bats in the region.

"Such losses could be even more substantial in the extensive agricultural regions in the Midwest and the Great Plains where wind-energy development is booming and the fungus responsible for white-nose syndrome was recently detected," said Tom Kunz, a professor of ecology at Boston University, another co-author.

White nose fungus has not yet been detected in Minnesota, but it's spreading west quickly. The disease first appeared in upstate New York four years ago, and has now been found in 16 states and 3 Canadian provinces. Bat declines in the Northeast, the most severely affected region in the U.S. thus far, have exceeded 70 percent. Populations of at least one species, the little brown bat, have declined so precipitously that scientists expect the species to disappear from the region within the next 20 years.

The article, "Economic importance of bats in agriculture," appears in the April 1 edition of Science. Authors are J.G. Boyles, P. Cryan, G. McCracken and T. Kunz.