The healthy little brown bats roosting close to the bat
with white-nose syndrome risk infection with the fungus
The deadly fungus that causes white-nose syndrome is sweeping through North American bat populations, and little brown bats are adapting their behavior to avoid it. Although these bats typically clump together in large groups, they are now spreading out to roost separately, a change in behavior that may be helping the bat populations rebound. So what does a bat-killing fungus have to do with human prejudice? The bats’ trick of splitting up to survive contagion may also have led humans to divide into tribes and respond hostilely to members of different, potentially diseased groups.
In a post on Scientific American’s Guest Blog, biologist Rob Dunn writes about the link between infectious diseases and human prejudice.
What’s the News: Bats are an economic boon worth approximately $23 billion per year, and possibly up to $54 billion, to U.S. agriculture, a study in today’s issue of Science estimates. Their voracious appetite for insects—a colony of 150 brown bats eats about 1.3 million pesky, crop-chomping bugs each year—means that bats function as effective, and free, natural pesticides.
The continued onslaught by white nose syndrome against North America’s bats is one of the stories of the year—number 13, in fact, on DISCOVER’s Top 100 of 2010. But some help soon could be on the way in the form of Endangered Species Act protection. Earlier this month, a group of conservationists and scientists filed an emergency petition with the United States Fish and Wildlife Service to list the little brown bat under the act.
Emergency listing for a species does happen, but not very often, says Ann Froschauer, national white-nose syndrome communications leader for FWS. “Given the urgency of white-nose syndrome and recent information about predicted declines in little brown bat populations, the Service is committed to quickly reviewing scientific information, both published and provided by organizations such as these, in assessing the status of little brown bats and other bat species affected by WNS.” [Scientific American]
Listing the bats as endangered could force government action to protect them, including increased funding and the designation of critical habitat.
When we last covered little brown bats it was with big bad news: A study in Science suggested that white nose syndrome could kill enough of the bats to make them regionally extinct in many parts of the United States by 2020. This week, though, brought a glimmer of hope. Scientists at the New York State Department of Health led by Vishnu Chaturvedi say some anti-fungal drugs work against the mysterious fungus causing the bat die-off.
They tested six strains of the novel fungus against drugs already used to treat people and animals such as cats and dogs for ailments ranging from athlete’s foot to life-threatening infections. “We found that two major classes of antifungal drugs have very good activity” against the bat germ, Chaturvedi reported Sunday in Boston at a meeting of the American Society for Microbiology. The drugs include fluconazole, the most widely used antifungal drug, which is sold as Diflucan by Pfizer Inc. and in generic form. Four other drugs also seem highly effective, Chaturvedi said. [AP]
Five years ago, there were six and a half million little brown bats in the Northeastern United States. In 2020, there may be next to none.
This week in Science, a study models the collapse in bat populations brought on by white-nose syndrome, which was first found in 2006 and is seemingly caused by a nasty fungus. Researchers think that bats with the affliction awaken too early from hibernation, messing up their natural cycles and draining their reserves of energy. A team led by Winifred Frick checked the math on bat population decline and found that they could be locally extinct in many parts of the United States by 2020.
The loss of all these bats would be bad for us, not just them, because they like to dine on pesky insects. So far, researchers have little idea how to cure diseased bats or stop the blight from spreading. The U.S. Forest Service last month proposed to close off abandoned mines in several states, hoping to protect the bats who live in them from the disease. For more about the bats, check out Ed Yong’s Not Exactly Rocket Science.
80beats: Frog Species Are Hopping Into Extinction Before They’re Even Discovered
80beats: Bats Are Dying from White Nose Mold, But Researchers Aren’t Sure Why
80beats: With Chirps and Trills, Bats Sing Love’s Sweet Song
Not Exactly Rocket Science: Pocket Science – lessons from spongy genomes, and a deadly bat-killing disease
Image: Al Hicks, NY DEC
With the cause of a rampantly deadly bat illness still unknown, biologists have no solution to the problem but have proposed at least a quick fix that may be able to slow it down. At least half a million bats throughout the northeast United States have died from white-nose syndrome (WNS), a fungal infection that was first observed only two years ago. The fungus is thought to grow on bats’ facial skin and flight membranes, possibly causing them to starve. No one knows where the fungus came from, or if it is what is directly killing the bats. But in caves where it has been observed, bats have suffered morality rates ranging from 75 to 100 percent [Scientific American]. With the cause of the fungus not yet determined, researchers worry about the fate of bats, which play an important role in controlling the populations of insects that can damage wheat, apples and dozens of other crops [AP].
While it won’t solve the problem, a temporary stop-gap is now being considered that would place battery-operated heated boxes inside bats’ hibernation caves, and may give the animals the energy they need to fight off, or at least survive, the fungal infections [Scientific American]. The idea is based on the fact that the bats with WNS appear emaciated, as if they’ve starved to death during their winter hibernation; researchers theorize that afflicted bats rouse from hibernation more often than normal bats and thus burn more fat to stay warm [AP]. When they temporarily stir, the bats’ body temperature and metabolism spike.
Researchers have gathered some clues to solve the mystery of what’s killing off hibernating bats throughout New England, but say they’re still far from knowing how to halt the strange die-off. In a new study, researchers identified the characteristic white fungus that has been found on the noses of dead and dying bats, and say it’s a new species of mold that thrives at low temperatures like those found in caves in the winter. But debate still continues over whether the fungus is the cause of death, or simply a secondary infection that takes advantage of bats with already weakened immune systems.
Bats covered with the fungus, a sickness now called white-nose syndrome, were first spotted in Howes Cave near Albany, N.Y., during the winter of 2006. At that time, field biologists reported caves that were typically covered with hibernating bats had loads of vacancies…. In one case, a cave floor was littered with dead bats [LiveScience]. Since then, the epidemic has spread throughout Connecticut, Massachusetts, Maine, and Vermont, with 80 to 100 percent of bats dying in some caves.