A decade fighting a deadly bat disease

You can hear the desperation in Christina Kocer’s voice, as she describes how it felt to find bats dying from a mysterious cause in the winter of 2007. She and other scientists watched helplessly as bats in the Northeast succumbed to what would become known as white-nose syndrome, a disease that has devastated bat populations.

“Bats weren’t behaving normally. In the middle of winter, when they should have been hibernating, we were finding them flying around outside their caves,” says Kocer, white-nose syndrome coordinator for the Fish and Wildlife Service’s Northeast region. “By 2009, it looked as though all bats would be gone.”

Fortunately, ten years on, all bats are not gone. But neither is the threat. While we’ve learned a lot, biologists like Kocer continue to race the clock, looking for ways to detect, treat, and reduce the spread of the disease. The Service, along with federal, state, and private partners, has completed a national response plan for managing white-nose syndrome and is carrying it out.

You don’t need to be a scientist to be concerned. Bats are important not only from an ecological standpoint, but also from an economical one. They eat tons of insects nightly, providing a natural benefit to farmers and foresters, not to mention those who enjoy the outdoors. Some research suggests that bats could save American agriculture more than 3 billion dollars in pest control every year.

A single bat eats thousands of insects a night, offering free pest management. Credit: Ann Froschauer, USFWS

Since its discovery, white-nose syndrome has spread rapidly throughout the eastern U.S. and Canada and is now found in 31 states and five provinces. It has killed more than six million bats, with mortality rates exceeding 90 percent for many sites and species. It has been confirmed in nine species, two of which are listed under the federal Endangered Species Act as endangered and another as threatened.

We now know that white-nose syndrome is caused by a fungusPseudogymnoascus destructans, or Pd for short — that’s primarily spread among bats as they hibernate in caves and abandoned mines. Pd disrupts bats’ hibernation, causing them to rouse more frequently and for longer periods of time during the winter, burning up their stores of fat. Some even leave their caves and mines during the winter and early spring and become victims of hypothermia, predation, and starvation.

We’ve learned that some species, like the little brown bat, tri-colored bat, and northern long-eared bat, are more susceptible to the disease, while others show resistance.

Little brown bat infected with white-nose syndrome in Greeley Mine, Vermont. Credit: Marvin Moriarty, USFWS

Scientists today have new ways of detecting the fungus, including using ultraviolet light. Field research on treatment has begun, and work on vaccines and molecular and genetic tools to improve bat survival is underway.

Bats aren’t the only ones who hang out in caves and abandoned mines. People who enter places where bats hibernate, whether for work or recreation, can pick up the Pd fungus on their clothes, shoes, and gear, and spread it to the next site they visit. The Service and its partners have created decontamination protocols that have reduced the spread of the disease by humans.

It’s important that all cave visitors follow decontamination protocols to reduce the spread of white-nose syndrome. Credit: Wikipedia via Creative Commons

There have been some promising developments. Little brown bats have survived multiple years of infection, and some bat colonies that were nearly wiped out are gradually growing in numbers, bringing hope for recovery.

When asked about the outlook now, Kocer seems cautiously optimistic.

“There is evidence of little brown bats surviving white-nose syndrome and reproducing,” she said. “Juveniles have been born, survived, and reproduced.”

What we’re working for: healthy little brown bats. Credit: Ann Froschauer, USFWS

And while a decade may seem like a long time, Kocer notes, “Ten years is roughly the lifespan of a little brown bat, so we’ve seen only one generation since the disease was discovered.”

In that generation, we’ve learned a lot about white-nose syndrome and the importance of communication and collaboration in fighting wildlife diseases. While the situation remains dire, the knowledge and experience gained will guide the Service and its partners in the fight to stop white-nose syndrome in the next generation, and address mysterious illnesses in the future.

Visit our Bat Conservation Map to learn more about these amazing creatures.

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