By Michael Winter
Federal biologists announced today that up to 6.7 million bats in 16 states and four Canadian provinces may have died from the white-nose fungus since it was detected six years ago, a die-off that a conservationist today called “a potential extinction event,” The Washington Post reports.
The U.S. Fish and Wildlife Service said that at least 5.5 million bats are estimated to have died from so-called white-nose syndrome, a disease first documented on bats hibernating in cave near Albany in February 2006. Biologists report mortality rates of 90% to 100% at some sites and expect the disease to keep spreading through several species, including some that are endangered.
The cause is a mystery. One theory is that humans may have introduced the fungus while exploring caves.
Last May, Fish and Wildlife unveiled a plan to combat the disease, and in October, federal and academic biologists concluded the fungus was in fact killing off bats in caves and mines across North America.
The new die-off figures come just before another hibernation season and are several times greater than a previous estimate.
“This startling new information illustrates the severity of the threat that white-nose syndrome poses for bats, as well as the scope of the problem facing our nation. Bats provide tremendous value to the U.S. economy as natural pest control for American farms and forests every year, while playing an essential role in helping to control insects that can spread disease to people,” Fish and Wildlife Service Director Dan Ashe said in a news release.
He said the agency is working with 140 partners “to understand the spread of this deadly disease and minimize its impacts to affected bat species.”
A map shows the extent of the pandemic.
Here’s how the Fish and Wildlife Service explains the disease:
While they are in the hibernacula, affected bats often have white fungus on their muzzles and other parts of their bodies. They may have low body fat. These bats often move to cold parts of the hibernacula, fly during the day and during cold winter weather when the insects they feed upon are not available, and exhibit other uncharacteristic behavior.
In May 2009, Fish and Wildlife ordered thousands of caves and former mines in national forests in 33 states to be closed for up to a year to try to control the fungus.
“We’re watching a potential extinction event on the order of what we experienced with bison and passenger pigeons for this group of mammals,” Mylea Bayless of Bat Conservation International in Austin told the Post. “The difference is we may be seeing the regional extinction of multiple species. Unlike some of the extinction events or population depletion events we’ve seen in the past, we’re looking at a whole group of animals here, not just one species. We don’t know what that means, but it could be catastrophic.”