Bacteria that kills bats may have reached Southern California

A cold-loving fungus that has killed millions of bats across North America has significantly expanded its range in California, potentially establishing itself from the northern tip of the state to the southern tip.

State and federal wildlife officials say the fungus is now present in five counties: Humboldt, Sutter, Placer, Amador and Inyo, after it was first detected in the Golden State last year. There may be at least six others as well.

Pseudogymnoascus destructans This fungus causes the deadly white-nose syndrome. It is named for the distinctive snow-like fuzz that appears on the petite faces of infected bats.

In 2022, the Biden administration declared the northern long-tailed bat as endangered. This is a last-ditch effort to save the species, which is on the brink of extinction due to a deadly fungus. This bacterium is now in California.

(Wisconsin Department of Natural Resources, via Associated Press)

The fungus invades the skin tissue of hibernating bats, causing them to wake up too often or too early during the winter, depleting their valuable fat reserves when food is scarce. The result is often starvation, dehydration, and death.

So far, California bats have shown no signs of the disease, which causes holes in their delicate wings and can cause them to flutter indiscriminately during the day, but wildlife officials say they may soon develop the disease. I believe it is.

“I wouldn't be surprised if it happens next year,” said Bronwyn Hogan, regional white-nose syndrome coordinator for the U.S. Fish and Wildlife Service. “But I wouldn’t be surprised if it took three or four years.”

Last year, California wildlife officials confirmed the presence of the fungus in a bat roost in Humboldt County on the north coast. This is the first conclusive detection in California, although officials have recorded low levels in the state. Back in the winter of 2018. This year's test results showed it is taking hold in four more counties.

Recent tests have found low levels in Southern California's San Diego and San Bernardino counties, as well as far-flung Northern California counties of Trinity, Siskiyou, Shasta and Plumas. wildlife protection authorities I called these results Some experts see them as writing on the cave walls, although they are “inconclusive” as they do not consider them to be sufficiently robust.

“These early signals can help us understand how the fungus is progressing and where it will reach,” said lead researcher Winifred Frick. bat conservation international He is an adjunct professor of ecology and evolutionary biology at the University of California, Santa Cruz.

Experts reacted with resignation to this news. Hogan said she was “disappointed,” but the spread was not unexpected. Scientists have known for years that the fungus exists in low concentrations in several parts of the state. And they increased their surveillance.

California state and federal wildlife officials, along with other partners, are working closely on efforts to confirm the fungus and disease through sampling and observation. Biologists collected samples from nine locations in California this year, swabbing the noses and forearms of small animals, said Katrina Smith, statewide coordinator for small mammal conservation for the California Department of Fish and Wildlife. .

This fungus has been linked to 25 species of bats in California, including the little brown myotis, Yuma myotis, long-legged myotis, the large brown bat, the Mexican free flying fox, and the first western spotted bat ever recorded. occurs in many cases.

Mexican free-tailed bats are filling the skies over San Antonio.

(Bob Dean / How to look at nature photography / Bat Conservation International)

The origin of white-nose syndrome has a science fiction twist. When biologists first encountered bats dying from the disease in a cave near Albany, New York, in 2007, the fungus behind the destruction was unknown to science. According to federal officials. (It has since been discovered in bats in Europe and Asia, and bats appear to be resistant to invaders.)

No one knows how the fungus arrived in North America, but it quickly spread across the United States and Canada, leaving behind tons of dead bats in its death march. Many of the victims were small brown bats.

Scientists tracking the spread were surprised when the disease first appeared on the West Coast in 2016, when a hiker discovered a dying bat on a trail in Washington state.

“We've changed a lot from where we were in the center of the country,” said Jeremy Coleman, national white-nose syndrome coordinator for the U.S. Fish and Wildlife Service.

Officials estimate that the syndrome killed more than 6 million bats across the United States in 2012. The current number of victims is probably much higher, and authorities are working on updates. (Officials say the fungus is not known to cause disease in humans or other animals.)

California bats are more elusive than their eastern counterparts, which congregate by the thousands in caves and mines. Golden State bats are thought to congregate in small numbers in rock crevices, swaying palm fronds, highway underpasses and other hard-to-find hiding places.

The uniqueness of the West Coast can be both a blessing and a curse. On the other hand, the spread of bats across the landscape could slow the march of white-nose syndrome, which is prevalent primarily when bats preen or interact with each other.

But that makes it hard to know what's going on with them.

“There is some hope that the impact of this disease may not be as dramatic, but it may just be difficult to measure,” Frick said.

In areas where bats congregate in large groups, researchers can go into caves that bats are known to frequent and count the number of bats to see if they are becoming extinct.

Coleman said the disease typically develops one to two years after the fungus is detected.

“Unfortunately, we're in California now, so from what we know, and all the other places we've seen the spread of the fungus, the disease is going to come out at some point,” he said.

Bats, the only flying mammals, provide inexpensive pest control by preying on insects, including those that target crops. The annual state contribution to farmers is estimated at $3.7 billion. Their guano, or dung, can also be used as fertilizer.

The state of California is currently discussing the possibility of vaccinating bats. Vaccination could increase the winged creatures' chances of surviving if they develop white-nose syndrome, Smith said, but injecting bats individually would be laborious.

“This just provides a chance for some people to develop resilience to this disease, and we hope that over time some of them will survive and find a way to overcome it.” ” she says.

They are also awaiting results on other possible options, such as probiotic powders that could strengthen the bats' skin microbiome and slow fungal growth. researcher tested Blow probiotic-containing dust into the bats' roosts when they go out at night, so that it covers them when they return.

A colony of Mexican free flying foxes under the Yolo Bypass Wildlife Refuge.

(Carolyn Cole/Los Angeles Times)

Some bat boosters take a more creative approach.

Bat Conservation International, a non-profit organization, fat butt projectThis is intended to help the furry mammal gain weight before and after the onset of winter.

Frick said the idea is that because white-nose syndrome causes bats to shed fat during hibernation, heavier bats are better able to withstand physiological disruptions that are often fatal.

The nonprofit is testing ways to attract insects to bats by installing ultraviolet lights near their hibernation chambers, a cool-sounding plural for bat shelters.

“We like to call it a bug buffet,” Frick said.

The public is calling for report Report sightings of sick or dead bats, or bats behaving abnormally, such as flying during the day, to California wildlife officials.. However, humans should not handle animals.