WILDLIFE: Fungus is likely bat killer — study
Paul Voosen, E&E reporter
Published: Thursday, October 27, 2011
A lab study has seemingly confirmed that a cold-loving fungus is the source of white-nose syndrome in North American bats, a disease that has caused mass bat fatalities in the Northeast while spreading to 16 states. A paper describing the researchers’ work was published yesterday in the journal Nature.
The study, led by U.S. Geological Survey scientists, found that the fungus Geomyces destructans, when introduced to otherwise healthy little brown bats hibernating in a lab, caused the common symptoms of white-nose syndrome, including fungal skin lesions on their wings. The disease spread by touch from infected to healthy bats; it did not, however, appear to spread through the air.
Scientists believe they have identified the cause of white-nose syndrome, a condition that has caused mass bat fatalities across North America. Photo courtesy of USGS.
Earlier this year, European scientists identified a variant of G. destructans that was widespread in healthy bats across Europe. The current study supports the notion that the fungus spread from these adapted populations to North America, perhaps through tourist traffic, wrote the researchers, who were led by David Blehert, a USGS scientist at the National Wildlife Health Center.
The researchers did document one oddity: While healthy bats exposed to the fungus developed the lesions seen in white-nose syndrome, the lab-infected bats did not lose weight or die at the rate seen in wild infected specimens.
Indeed, according to both measures, the bats did not differ from a healthy control group. The researchers chalked this disparity up to the bats’ limited exposure time of 102 days; in the wild, bat fatalities peak at 180 days after the start of hibernation, they said.
The scientists argue their study establishes G. destructans as the cause of white-nose syndrome. Previously, some have suggested that the fungus only infects already unhealthy bats. The termination of the study after a hibernation-mimicking 100 days, before mortality could set in, would seem to allow those doubts to linger.