A hiker who noticed a little brown bat dying on a trail near the slopes of the Cascade Mountains in western Washington did what he could to save it. He took it to an animal health center, but within two days it was gone.
The death in mid-March seemed unremarkable until a veterinarian who examined the animal made a discovery that set off alarms heard all the way to Washington, D.C. The bat showed advanced signs of white-nose syndrome, a mass killer that emerged in New York about 10 years ago and slowly migrated as far west as Nebraska, leaving nearly 7 million bats dead in its wake. Its sudden, thousand-mile leap to the Pacific Northwest is a grave concern to every biologist who studies the winged mammals.
The find potentially opens up a second epicenter for the fungus. Even now, scientists don’t know precisely where it came from, much less where it’s going. All they know is that it kills virtually every bat it touches.
“I think this is really bad,” said Katie Gillies, director of the Imperiled Species Program at Bat Conservation International in Texas. “I really do think this is a big leap. Now we’re going to see it radiate from that new point. It’s like having breast cancer and finding that it’s metastasized.”
The U.S. Fish and Wildlife Service, which has tracked white-nose syndrome since 2006, also expressed alarm, but with far more reserve. The next steps will involve genetic testing of the dead bat, along with analysis of the disease that killed it, and then a state-led sweep of the trails and mountain crevices visited by bats near the hiker’s discovery.
“We are extremely concerned about the confirmation,” Fish and Wildlife Service Director Dan Ashe said in a statement. “Bats are a crucial part of our ecology and provide essential pest control for our farmers, foresters and city residents, so it is important that we stay focused on stopping the spread of this fungus.”
Wildlife biologists want to be sure of where this disease strain originated. Among the questions they’re seeking to answer: Did a traveler track it from Europe or Asia all the way to the west coast? Or did some cave explorer get the fungus on his or her gear in the east and bring it west? They want at least a clue to how long the fungus has lived out west. Considering the haggard condition of the dead bat, including its ravaged wings, a tell-tale sign of white nose, it’s been there for a while.
“Every single avenue we look at seems far fetched,” said Greg Falxa, a wildlife biologist for the Washington Department of Fish and Wildlife. “This bat had the deterioration already, which suggests the fungus didn’t just get here this year. Who knows how it got here? Everything is speculation right now. We’re starting surveillance in that area.”
That immediate surveillance is yet another sign of the degree of concern. White-nose syndrome has nearly pushed brown bats in Pennsylvania and New York to extinction. It’s now established in at least 25 states and several Canadian provinces.
Their loss has substantial implications for humans. Bats eat insects by the metric ton every night, with a pregnant female capable of devouring nearly a hundred moths and other pests. In a single summer, a colony of 150 brown bats can eat enough adult cucumber beetles to prevent the laying of eggs that result in 33 million rootworm larvae, according to a study cited by Bat Conservation International.
Without bats, insects would be free to ravage farm crops and trees, among other things. Their value to U.S. farmers has been estimated at $3 billion a year. In addition to little brown bats, long-eared bats, big brown bats, Indiana bats and grey bats have been impacted.
Falxa said the latest discovery led to a frenzy of conferences between his agency, Fish and Wildlife and the U.S. Geological Survey. They have one hope: Bats in the west don’t congregate in caves and mine shafts by the tens of thousands the way they do in the east, so maybe, Falxa said, the fungus won’t spread as fast.
But Gillies, who was once a biologist in Nevada, called that a false hope. “We’ve got 15 western species that have the potential to be infected,” she said. “Containment is not going to be possible.”
Gillies offered a prediction, saying that as the fungus wipes out the most susceptible bats, others will flourish in their absence because of less competition and a larger abundance of food. Still, even if they develop an immunity to the fungus as their counterparts did in Asia and Europe, “bats are really long lived… and slow to reproduce,” she said. “They’re very slow to rebound. We won’t see it in our lifetime.”