Federal scientists confirmed the fungal epidemic has struck a second species of endangered American bats

By Janet Raloff

Web edition: May 29, 2012

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Already endangered victims

Scientist inspects a gray bat for signs of white-nose infection.

Credit: USFWS/Ann Froschauer

The news on white-nose syndrome just keeps spiraling downward. The fungal infection, which first emerged six years ago, was reported May 29 in a seventh species of North American bats — the largely cave-dwelling grays (Myotis grisecens). The latest victims were identified while hibernating this past winter in two Tennessee counties.

Biologists observed tell-tale threadlike fungal fibers on the faces, wings and tail membranes of several bats. None of the victims were dead. Preliminary cellular diagnosis of the disease was made from specimens sent to the University of Georgia, and later by white-nose specialists at the U.S. Geological Survey’s National Wildlife Health Center in Madison, Wisconsin.

To date, the disease has been documented in bats in 19 states and four Canadian provinces. Scientists say their best guess is that at least 6 million American bats have succumbed to this pandemic.

Seven of the 45 species of U.S. bats are endangered with extinction. The gray bat was added to the Endangered Species list in 1976. The bats' primary range spans from Alabama northward into Missouri and Kentucky. A few outlier communities can be found in Florida, western Virginia, Illinois, Indiana and Oklahoma. An estimated 90 percent of the species — now hovering at several million animals — depend on fewer than 10 caves for their hibernation.

White-nose infections have killed some endangered Indiana bats, which despite their name can be found throughout the Northeast and Mid-Atlantic states. Added to the Endangered Species list in 1967, a 2009 census of the species pegged the national population of Indiana bats at fewer than 400,000 animals.

“[T]hat another federally endangered bat species, the gray bat, has been confirmed with white-nose syndrome is devastating for anyone who cares about bats and the benefits they provide to people,” U.S. Fish and Wildlife Service Director Dan Ashe said in a prepared statement.