Scientists fear white-nose syndrome has killed many more bats than they previously thought

Scientists have been trying to determine the cause of white-nose syndrome in North American bats since it was discovered five years ago. The disease has been killing bats at an alarming rate, and now researchers fear many more have died than previously thought, estimated at 5.7 to 6.7 million, Louis Sahagun of the Los Angeles Times reports. The disease seems to affect the 25 species of hibernating bats, but scientists say all 45 species of North American bats could be at risk. (Times photo by Mark Boster: Bag holds bat found in cave believed to have syndrome)

The estimate was difficult because common bat species have not been regularly counted. As mortality rates at some sites reached 100 percent, a team of 140 Canadian and U.S. researchers coordinated to come up with a number. Jeremy Coleman, national white-nose coordinator for the U.S. Fish and Wildlife Service, told Sahagun that since bats have low reproductive rates, it will probably take more than 100 years for populations to fully recover.

The disease has killed mostly little brown bats, one of the most common mammals in North America. The species has lost 20 percent of its population in five years. Bats who contract it exhibit unusual behavior during winter, like flying outside and clustering around cave entrances when they should be hibernating, and they can freeze to death. Researchers are trying to find a treatment, including vaccination or manipulating cave environments. (Read more)