Scientists studying white nose syndrome in bats estimate the fungal ailment has killed at least 5.7 million bats in the U.S. and Canada.

White nose is caused by a fungus that prompts bats to wake from their winter hibernation and die after they fly into the cold air in a doomed search for insects. First detected in a cave west of Albany in 2006, federal authorities say infected bats have been found in 16 states from the Northeast to the South and as far west as Indiana and Kentucky. It also has been detected in four Canadian provinces.

The U.S. Fish and Wildlife Service says Tuesday the new estimate shows the severity of the threat to bats.

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