A mysterious scourge is killing North America’s bats, millions of them. First detected in upstate New York just over four years ago, white-nose syndrome—so named for the white fungus that appears on the muzzles and wings of affected animals—has quickly spread to states in the South and Midwest. Last winter, researchers in Canada found infected bats. Missouri’s first cases were identified near St. Louis earlier this year. In all of these places the disease has been devastating.
In the old mines and caves that bats call home, mortality of nearly 100 percent in some species has been documented, according to Kathryn Womack, a graduate researcher in MU’s School of Natural Resources. “At this point we believe the disease causes the bats to die of starvation during what is normally their hibernation period,” Womack said. “The fungus irritates them and causes them to awaken more often, using stored fat reserves they need to survive through the winter.”
While the disease’s pathology is clear, its long-term effects on bat survival is less so. Womack, an experienced bat-rehabilitation volunteer, is among a tight-knit community of bat researchers racing to come up with answers.
And time is indeed of the essence. At least nine species of bats are suffering the devastating effects of the illness, including three that are already on the endangered species list. The U.S. Fish and Wildlife Service estimates, for example, that the Little Brown bat population in 16 states from Maine to Tennessee has declined 17.2 percent in just two years. Bat numbers in Vermont are down as much as 80 percent. All told, according to Bat Conservation International, an authority on bat conservation and research, white-nose syndrome has killed more than a million bats in 11 states and Canada.
One key enquiry involves determining why some bats with white-nose syndrome manage to survive the winter. Womack’s part in this investigation stems from field work on a different project: using small radio transmitters to track endangered Indiana bats while they summer in “maternity colonies” found on Department of Conservation land in northeast Missouri. Her primary goal is to gather data on resource selection and prey availability for pregnant and lactating bats. But the information will also provide valuable baseline data about these vulnerable, but for now disease-free, bat colonies.
Some, inevitably, will question why anyone should care about these creatures. Humans have, after all, long harbored an almost instinctive revulsion for the creatures. Womack points to two reasons for our concern.
Perhaps the most obvious is that our irrational prejudices should not be allowed to obscure the magnificence of these flying mammals, some species of which are at least 50 million years old.
Another reason, she says, is that bats are voracious consumers of harmful insects, and thus an irreplaceable part of a complex ecosystem that affects all of us. Womack cites figures from the USDA warning that a significant reduction in bat populations could be a disaster for agriculture.
“A colony of only 500 Big Brown bats can eat up to 10 pounds of insects per night,” she says, adding that, at least for now, some Missouri caves are the winter homes of thousands of these and other insect-consuming bats. And, there, she hopes, they will long remain.