On March 11, a hiker near North Bend on the slopes of the Cascade Mountains in Washington state found a sick bat lying on the trail. He took the little brown bat, Myotis lucifugus, to the Progressive Animal Welfare Society where it died two days later.
At the time, a veterinarian at the clinic recognized that the bat had the signs of white-nose syndrome, a fungal infection caused by Pseudogymnoascus destructans—a diagnosis that the Washington Fish and Wildlife Department confirmed yesterday.
In the past 10 years, over 7 million bats in 25 states from New York to Nebraska have died from mysterious disease, but this is the first time the fungus has been recorded west of the Rockies, setting off alarm bells along the West coast.
“I think this is really bad,” Katie Gillies, director of the Imperiled Species Program at Bat Conservation International in Texas tells Darryl Fears at The Washington Post. “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.”
According to the Washington Department of Fish and Wildlife, the white, fuzzy fungus grows on the nose, wings, and ears of bats as they hibernate during winter and can also damage skin tissue. The bats wake up more often during their long nap, burning through their limited fat reserves, which eventually leads to starvation. The disease can also cause wing damage, dehydration, and impaired circulation.
So far, researchers are not sure where the disease comes from, but they suspect it was transported from Europe on the gear of cavers. It is spread from bat to bat and through spores that can contaminate clothing, though the disease is not harmful to humans.
In the East, the disease has caused complete mortality of some bat colonies, and it has pushed the little brown bat, the most common bat in the U.S., to near extinction in New York and Pennsylvania. Many other bat species face catastrophic die-off rates over the next few decades.
According to the Seattle PI, authorities are sure that the affected bat comes from Washington and is not an eastern bat that lost its way because it is a subspecies of little brown bat that only occurs in the West. Eleven other species of bats in the state are also at risk from the disease.
Not only is the loss of bats bad for biodiversity, it also affects people. According to Fears, bats provide over $3 billion worth of insect removal to farmers annually, and one colony of 150 brown bats can eat enough cucumber beetles in a summer to prevent the hatching of 33 million rootworm larvae.
“The implications of losing our bat population can be potentially quite dire,” Washington Fish and Wildlife veterinarian Katie Haman said during a news conference. “The long term implications of catastrophic declines in our bat populations could be really hefty. Bats are incredibly important and the predictions from what we've learned in the Eastern ecosystem is that this could have really huge impacts.”
How the disease got to Washington and how long it has been in the state are not known. “This bat had the deterioration already, which suggests the fungus didn’t just get here this year,” Greg Falxa, a wildlife biologist with the Department of Fish and Game tells The Washington Post. “Who knows how it got here? Everything is speculation right now. We’re starting surveillance in that area.”
But Mollie Mattson, a senior scientist with the Center for Biological Diversity has an opinion on how white-nose made it to the West. “This disease just made a jump of more than 1,000 miles, so it’s pretty reasonable to think this could be a human-caused transmission,” she says in a press release.
“What’s absolutely heartbreaking about this news is that there were obvious things wildlife and land managers could have done to stem the spread, including prohibiting nonessential cave access into public land caves. They could have passed rules requiring that no caving gear or clothing from WNS-positive states be allowed in caves in unaffected states," she says. "This is a wake-up call for land managers in the West to do what's needed to keep white-nose syndrome from spinning out of control before it’s too late.”