A deadly fungus is pushing these bats towards extinction, says the government


It thrives in cold and dark, infesting the muzzles of sleeping bats. The deadly fungus hops from bat to bat, awakening the winged mammals from their winter slumber as they huddle in caves. It can lead bats to dehydration and starvation, leaving cave floors littered with carcasses.

The US Fish and Wildlife Service on Tuesday proposed adding the tricolor bat, one of several species affected by the deadly fungus, to its endangered species list. The bat population has declined so much over the past decade that it may now be extinct in the wild.

The decision by federal wildlife managers underscores the threat of extinction facing hundreds of thousands of species worldwide. The decline of bats in particular – due in part to deadly diseases, as well as other damage – threatens to upend ecosystems and harm farms that rely on voracious insect eaters to control pests.

The culprit harming these bats is known as white nose syndrome, an exotic fungus first discovered about 15 years ago in an upstate New York cave that was since widespread over more than half of the bat’s range. Sick bats – with fuzzy growths on their noses – have been found from the Atlantic coast to the foothills of the Rocky Mountains, with affected colonies experiencing declines of more than 90%.

“It’s pretty heartbreaking to walk in and see what were once huge colonies of bats now struggling,” said Jonathan Reichard, deputy national coordinator for white nose syndrome at the Fish and Wildlife Service, describing caves where he would see “dying bats”. crawl in the snow.

The tricolor bat in particular “has been in trouble for a long time,” said Beth Buckles, associate clinical professor of biology at Cornell, who co-authored a major paper describing the disease. She thinks the decision is long overdue.

“It takes a while for things to get listed, I understand that,” she said. “But the bats are in a very bad state.”

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No one knows exactly when or how White Nose Syndrome happened.

“We always assumed it was what we call human-mediated transport,” said Jeremy Coleman, national white nose syndrome coordinator for the US Fish and Wildlife Service. Experts suggest it could have arrived, for example, on the boot of a caver who brought it from Europe or Asia.

But scientists are sure that the fungus – nicknamed Pseudogymnoascus destructans for its destructive nature – is not from here. “We are very confident that this is not a native fungus in North America,” Coleman added.

With a strong immune system, bats can harbor many pathogens without getting sick – including, potentially, the coronavirus causing the pandemic in humans.

But the cold-loving fungus has evolved to attack the most vulnerable bats, during hibernation when they huddle together. Like a vampire, the mushroom works best in the dark. Despite its name, the disease can also creep up the wings of bats, leaving lesions and making it harder for the mammal to retain water.

“We call it white nose syndrome,” Buckles said, “but the fungus is all over their wings.”

The tricolor bat gets its name from the alternating dark and light spots on its fur. During the warmer months, the small mammal feasts at night on beetles, moths and other insects along river banks and forest edges. They find food in the dark by emitting an ultrasonic sound and listening to it bounce around.

The tiny species, which can weigh less than a quarter, faces threats beyond this disease. Changes in temperature and precipitation due to climate change can disrupt resting and foraging. And wind turbine blades can strike and kill animals.

But white nose syndrome remains by far the biggest threat.

A dozen different bat species are affected by white nose syndrome. Federal authorities proposed earlier this year to list the northern myotis as endangered. The agency is also considering granting a third species, the little brown bat, federal protections.

And the endangered Indiana bat was on the road to recovery before white-nose syndrome arrived, said Winifred F. Frick, chief scientist of the nonprofit Bat Conservation International. .

“As we’ve all experienced during covid, responding in real time to illness is really difficult,” she said. “And it’s even harder when you’re talking about wild animals.”

Passed nearly half a century ago, the Endangered Species Act makes it a crime to harass endangered animals. The law has been instrumental in reviving the numbers of gray wolves and other iconic North American creatures from poaching and habitat destruction.

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But the agency recognizes that imported diseases pose a different kind of threat. Researchers are now exploring a plethora of new treatments — including antifungals, probiotics, ultraviolet light, vaccines and even genetic engineering — to combat the fungus without harming other species.

“We didn’t even know the disease existed about 12 years ago,” Coleman said. “The development of these strategies to treat disease in wildlife is somewhat unprecedented.”

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