A mysterious disease that has caused mass fatalities of bats in the eastern U.S. is spreading westward with alarming speed.
White-nose syndrome – linked to a fungus that grows on bats’ skin – was first noticed in New York in 2006 and has already spread to 14 states and nine bat species.
According to the U.S. Fish and Wildlife Service, it has killed hundreds of thousands of bats, though researchers haven’t figured out exactly how it kills them.
After the disease was spotted in Missouri and northwestern Oklahoma, USFWS got serious and in July announced emergency closures of caves on federal lands in Colorado, Nebraska, Kansas, and most of Wyoming and South Dakota. A national response plan is in the works.
This week, the Bureau of Land Management announced an interim plan to stop the disease from spreading on its properties nationwide. The plan puts state BLM directors in charge of deciding whether to close caves with documented bat populations. It stops short of a request from the Center for Biological Diversity to close all caves on BLM turf in the lower 48.
White-nose syndrome – not known to affect humans – causes bats to come out of hibernation severely underweight, often starving, before the insects they eat have emerged in the spring. Once a colony is infected, it can kill more than 90 percent of bats in a cave in just two years.
Biologists think bats get the disease from each other and from fungus in cave soils. But they also say humans have probably transmitted the fungus from cave to cave inadvertently. Decontamination of clothing and caving gear is advised but doesn’t always kill the fungus.
The BLM plan directs more attention to surveying abandoned mines, working with other agencies, and listing sites for white-nose syndrome testing. Center for Biological Diversity conservation advocate Mollie Matteson said it doesn’t go far enough:
“Western land managers are finally waking up to the overwhelming threat of white-nose syndrome to bats, but this devastating disease simply will not allow the luxury of half measures. If the BLM is serious about protecting bats, then it needs to restrict access in all caves with bats.
“Here in the Northeast, most of our bats are gone. If westerners don’t want their bats to meet the same fate, they need to act fast and use what we now know about the disease to slow it down. Stopping human transmission is one big step toward doing that.”
How many caves should be closed to people to prevent bat deaths? I’d love to hear from some spelunkers.