Mysterious Bat-Killing Disease Found In 2 Va. Caves
Saturday, April 11, 2009
First, the frogs began disappearing, with as many as 122 species becoming extinct worldwide since 1980. Then honeybee colonies began to collapse. Scientists fear that bats might be next.
For the past three years, biologists in Virginia have been nervously watching a strange die-off of bats in the Northeast as a mysterious fungus spread rapidly through hibernating bat colonies, leaving caves that once served as safe havens for the hibernating creatures carpeted with the tiny, emaciated carcasses of an estimated 1 million dead bats.
Biologists here were hoping that the fungus would somehow be contained or would burn itself out. Instead, they were shocked last week when researchers confirmed the presence of the fungus, dubbed white nose syndrome for the ring of white fungus that collects on bats' muzzles and wings, in two caves in the state: Breathing Cave in Bath County and Clover Hollow in Giles County, hundreds of miles from the other known infected caves.
"We thought we'd have more time to prepare," said Rick Reynolds, a wildlife biologist with the Virginia Department of Game and Inland Fisheries. But it wouldn't have mattered. "Unfortunately, no one knows what to do about it."
What is known is this: As many as 90 to 100 percent of the bats in infected colonies have died within a year of finding the fungus. And with its spread this far south, there's no reason to think it will stop. Scientists are beginning to whisper the unthinkable: complete annihilation of some species.
Just south of the infected Virginia caves, in Kentucky, Tennessee and northern Alabama, gather some of the largest populations of hibernating bats in the world. And these bats have been tracked flying hundreds of miles from their home caves. They could potentially come into contact with and infect or be infected by any number of other species of bats and the as yet incurable disease could be unstoppable.
"If this continues to spread, we are talking about extinctions," said Thomas Kunz, an ecologist and bat expert at Boston University. "I've studied bats for 44 years. This is unprecedented in my lifetime. It's not alarmist. These are just the facts."
Bats, like the disappearing honeybees and frogs, play a critical role in the delicate balance of nature. A single bat will eat 50 to 100 percent of its body weight in insects in a single night. Kunz conservatively calculates that the million bats that have died would have consumed about 694 tons of insects in one year: the equivalent weight of about 11 Abrams M1 tanks.
"You take these bats away, there are a lot of unknowns," Kunz said. "What are these insects going to do that aren't being eaten? They can cause serious damage to crops, gardens and forests, further upsetting both the natural and human-altered ecosystems."
In one study of eight Texas counties, Kunz said, researchers found that if bats disappeared, farmers would have to spend as much as $1.2 million more on pesticides each year. That means more-expensive food, more chemicals in the food supply and the environment, and who knows what other cascading effects on the animals that depend on bats as a source of food or their guano for nutrition. "Eventually, there's a threshold that's going to be reached," Kunz said. "That's not going to recover."
White nose syndrome does not appear to affect humans. That's a blessing and a curse, Kunz said. "There's been little attention and little sense of urgency about this," he said. "Most of us are doing this research on a shoestring."
The fungus appears to be similar to a cold-loving fungus found in caves in Europe. Hibernating bats there, although their populations are far smaller than those in the United States, have shown signs of infection, but none have died.