Media & Education
News Room

December 2010, Volume 8, Issue 12

Are Little Brown Bats Endangered?

Scientists and conservation groups, including Bat Conservation International, are asking the U.S. Fish and Wildlife Service to determine whether little brown bats – once the most common bat species in the Northeastern United States – need protection under the federal Endangered Species Act. Scientists say White-nose Syndrome, which has already killed more than a million bats in the United States, could virtually wipe out little brown bats in the Northeast within the next two decades.

“The little brown bat is in imminent danger of extinction in its northeastern core range due to White-nose Syndrome, and the species is likely in danger of extinction throughout North America,” said Boston University biologist (and BCI Science Advisor) Tom Kunz. He coauthored a recent study on the dire impacts of WNS on the little brown bat.

Kunz and another bat scientist, Jonathan Reichard, conducted their own status review of the species, which was submitted along with the formal request to the Fish and Wildlife Service on December 16.

Because of the grave threat of this disease, the scientists and conservation groups recommended that the Fish and Wildlife Service place the little brown bat on the Endangered list as an emergency measure until the agency can complete its own assessment and make a final ruling.

“If the little brown bat, one of America’s most common and widespread bats, is facing regional, and possibly total, extinction, imagine the threat to less-adaptable and far-reaching species,” said Nina Fascione, executive director of Bat Conservation International. “More than half of the 46 U.S. bat species are potentially susceptible to White-nose Syndrome. We must protect the survivors before time runs out.”

The disease, first documented in upstate New York in 2006, already spread throughout the eastern United States, as well as Quebec and Ontario. It is now on the edge of the American West. Mortality rates of nearly 100 percent have been reported at some bat-hibernation sites infected with the disease.

“The little brown bat desperately needs protection under the Endangered Species Act,” said Mollie Matteson, conservation advocate for the Center for Biological Diversity. “Losing this species would be a tragedy that would have disastrous consequences for people and other wildlife.”

The continuing bat die-off already is causing ecological and economic impacts. The night-flying mammals play a critical role in keeping insect populations in check. Kunz has estimated that the WNS-caused loss of bats so far means that approximately 700 fewer tons of insects are consumed each year, including many pests that attack farm crops and commercial timber. Fewer bats will likely result in greater use of pesticides.

Those signing on in support of the status assessment request are Kunz and Reichard’s Center for Ecology and Conservation Biology at Boston University, Friends of Blackwater Canyon, Wildlife Advocacy Project, Bat Conservation International and the Center for Biological Diversity.

You can help BCI in its fight against White-nose Syndrome and other critical threats to bats. Please go to

You can help BCI in its fight against White-nose Syndrome and other critical threats to bats. Please go to

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