Redell, who studies bats for the Department of Natural Resources, lives every day now with the threat of a disease called white-nose syndrome hanging over his head. The disease, though not yet in Wisconsin, has killed more than 90 percent of the cave bats in Eastern states such as New York and Vermont. Experts predict it could make its way to Wisconsin, with its eight species and hundreds of thousands of bats, in as little as two years.
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One female little brown bat – with a body less than the length of your thumb – can eat its body weight in insects in one evening, Redell said. Such is the insect-hunting prowess of the bats that they are thought to save farmers billions of dollars in crop losses, according to Sheryl L. Ducummon, with Bat Conservation International.

In a recent scientific article on the ecological and economic importance of bats, Ducummon reported that, in one summer, the 150 bats in an average colony of big brown bats can conservatively eat 38,000 cucumber beetles, which attack corn and other farm crops. Damage from the beetle and their larvae cost corn farmers as much as $1 billion a year.

The loss of such an insect-eating force could be devastating, Redell said. The approximate 1 million bats that have already died of white-nose syndrome in the last three years on the East Coast would have eaten 700,000 tons of insects were they still hunting the night skies, he said.

Bats perform other important tasks, too. Several Western species serve crucial roles as pollinators for desert plants such as agave and as seed dispersers for dozens of species of cacti.
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“I mean, this is like a mouse that flies, but it has the predatory capabilities of a polar bear,” Blehert said. “They are physically adapted to command the night sky. You’re talking about a little thing with a body less than half the size of your thumb whose heartbeat can get up to 1,000 beats a minute when they are flying but that can slow when they are hibernating in the winter to 4 beats a minute. And they live 20 to 25 years!”