New Study Makes Alarming Predictions About Bat Populations

First posted on 08-10-2010

A rapidly spreading disease may wipe out as much as 99 percent of the bat population in the Eastern United States over the next 20 years. A Boston University study predicts that little brown myotis bats may be on the verge of extinction at that time.

The disease, White-Nose Syndrome (WNS), is a fungus that affects a bat’s wings and nose. The fungus becomes an irritant that disturbs a bat’s hibernation, causing it to wake up often and it ends up starving to death before hibernation ends. If the bat does make it through the winter and the disease spreads to its wings, WNS robs the animal of its ability to fly and catch insects for food. By the second year of infection, mortality rates are thought to be over 98 percent.

WNS was first discovered in a New York cave in 2006 and has spread to seven bat species throughout the east. The disease has also been confirmed in Missouri and Oklahoma, although Arkansas has yet to positively identify the presence of WNS.

Not much is known about the fungus, but research continues. It is believed to be spread by bat-to-bat contact during migration periods and through human-to-bat contact. In an effort to stave off further spread of the disease, dozens of caves throughout the Ozarks have been closed.

“This is one of the worst wildlife crises we’ve faced in North America,” said Winifred F. Frick, one of the lead scientists in the Boston College study. “The severity of the mortality and the rapidity of the spread of this disease make it very challenging and distressing. Researchers have been working very hard since it was first discovered four years ago to try to better understand the disease and find potential solutions to the problem.”

The results of a near extinction in bat populations can be devastating to ecosystems. Some cave-dwelling animals depend on bat guano for nourishment. In addition, only 500 of these voracious insect-eaters can consume up to 10 pounds of bugs each night. As bat populations decline, insects can thrive.

“This level of insect consumption provides an important ecosystem service to human kind, and to the balance of natural and human-altered ecosystems, which in turn can reduce the use of pesticides often used by humans to kill insect pests,” said Boston University biology Professor Thomas H. Kunz.

“Given the rapid geographic spread of this fungus over the past four years,” said Kunz, “we can expect that WNS will adversely affect bat species that form some of largest hibernating bat colonies in the U.S, including two federally-listed endangered species that occur mostly in the mid-western states.”

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