Bat deaths from wind turbines could mean higher insecticide costs, less profit for farmers

In 2010, more than 10,000 bats were killed by wind turbines in Pennsylvania, the state Game Commission reports. With 420 turbines across the state, that is about 25 bats per turbine per year, Erich Schwartzel of the Pittsburgh Post-Gazette reports, and that is bad not only for bats, but farmers who rely on bats for insect control. Suzanne B. McLaren of the Carnegie Museum of Natural History holds a Seminole bat reportedly killed near a turbine. (Gazette photo by Larry Roberts)

"A colony of just 100 little brown bats may consume a quarter of a million mosquitoes and other small insects in a night," Miguel Saviroff, agricultural financial manager at Penn State Cooperative Extension in Somerset County, told the Gazette.

Since bats consume as many as 500 insects an hour or 3,000 insects per night, fewer bats may lead to larger bug populations and larger pesticide bills for farmers, Schwartzel reports. Bats save farmers about $74 per acre, according to a county-by-county analysis of their economic value in the April 2011 issue of Science magazine. For all of Pennsylvania, that means an estimated savings of $277.9 million in avoided costs. (Read more) Here's the county-by-county estimate; click on the map to see a larger version.