A hiker found a bat with deadly white-nose syndrome along a trail east of Seattle, marking the first time the fungus-borne disease has appeared in the western United States.
“It’s very disheartening to see this long a jump,” said Chris Servheen of the U.S. Fish and Wildlife Service, which monitors the spread of white-nose syndrome. “It was documented by North Bend, Washington, and the closest evidence of white-nose before this was eastern Nebraska and northern Minnesota.”
The little brown bat was found on March 11 in an area not known for caves or hibernaculum, where large colonies of bats gather to hibernate through the winter. The fungus typically creates a powdery coating on a hibernating bat’s nose and mouth, depriving it of the energy it needs to survive the winter. It spreads from nose to nose in the densely packed confines of bat colonies.
White-nose syndrome was first detected in New York in 2006. It has subsequently killed millions of bats and wiped out entire regional populations in many parts of the eastern United States. To date, the fungus is confirmed in 27 states and five Canadian provinces.
Little brown bats (Myotis lucifugus) appear to be the most susceptible species to the disease. A PLOS-One study published in 2015 raised concern that “population models indicate that if mortality rates stay constant, this species could be extirpated from the northeastern United States within 16 years.”
“It’s shocking and disturbing to see this disease reach Washington and indeed the western United States,” said Mollie Matteson, senior scientist with the Center for Biological Diversity. “It certainly opens a new chapter in the spread of a disease that has already killed millions of bats. 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.”
A frequent and controversial response is to close caves to public access, on the assumption that people are spreading spores of the fungus from cave to cave. While there is evidence that the initial cases of white-nose syndrome may have derived from fungus spores brought from European ships to American ports, the cave-closure policy has been hotly debated.
“Some areas in the East have closed caves on public land,” Servheen said. “But in the West, we are working with the caving community as partners in this process. We see them as part of the solution, not the problem. They provide trip reports of bats when they see them and enforce clean-caving protocols.”
Montana has a world-renowned cave collection, ranging from Lewis and Clark Caverns State Park to what is the potentially deepest cave in North America in the Bob Marshall Wilderness. However, it has remarkably few large colonies of bats that hibernate together for the winter.
White-nose syndrome does not affect humans, livestock or other wildlife. The bat the hikers found died two days after it was delivered to the Progressive Animal Welfare Society for examination. It has since been sent to the USGS National Wildlife Health Center in Wisconsin for fungal, molecular and DNA analysis.
“We are extremely concerned about the confirmation of WNS in Washington state, about 1,300 miles from the previous westernmost detection of the fungus that causes the disease,” FWS Director Dan Ashe said in an email 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.”