Fast-spreading fungus threatening useful U.S. bats

Randolph E. Schmid, Associated Press Yahoo News 5 Aug 10;

WASHINGTON – One of the most common bat species could face extinction in the Northeast within decades due to white-nose syndrome, a disease now rapidly spreading.

While bats may have a bad reputation, frightening many people, they are vital in controlling insects that not only annoy but spread disease to people and animals.

The threatened little brown bat has been known to eat its weight in insects in a night.

Yet researchers led by biology professor Thomas H. Kunz of Boston University report in Friday's edition of the journal Science that white-nose syndrome, caused by a fungus, could all but wipe out the little brown bat in the Northeast in 20 years.

The syndrome was first discovered near Albany, N.Y., in 2006, and since then bats have declined from 30 percent to 99 percent in various areas. The illness has been confirmed in 115 bat hibernating locations in Canada and the U.S., ranging as far south as Tennessee and west to Oklahoma, the researchers reported.

Last month the U.S. Forest Service said it is barring entry to caves on service-owned land in Colorado, Wyoming, Nebraska, Kansas and South Dakota to help prevent people from inadvertently spreading the disease there.

And the New Mexico-based Center for Biological Diversity has asked state wildlife officials across the country to consider closing state-owned caves to the public to prevent the spread of the illness.

"This is one of the worst wildlife crises we've faced in North America," said co-author Winifred F. Frick. "The severity of the mortality and the rapidity of the spread of this disease make it very challenging and distressing."

The fungus grows on the nose, wing membranes and ears of bats while they hibernate in caves and mines during the winter. The researchers said this causes the bats to wake up frequently, burning up vital fat stores, with the result that they starve to death before spring.

Fungus Threatens Extinction Of Some U.S. Bats: Study
Maggie Fox PlanetArk 5 Aug 10;

Deadly white-nose syndrome is threatening to make one insect-eating species of bat extinct, at least regionally, U.S. researchers reported on Thursday.

The infection is spreading quickly across the Northeastern United States and Canada and is likely to cause the regional extinction of the little brown myotis bat, the researchers report in the journal Science.

It had been one of the most common species of bats in North America and was considered beneficial because of its appetite for mosquitoes, flies and other pests.

"This is one of the worst wildlife crises we've faced," said Winifred Frick of the University of California, Santa Cruz.

"Bats affected by this disease are all insect-eating species, and an individual bat can consume their body weight in insects every night, including some consumption of pest insects."

The syndrome, linked to a fungus that spreads among bats as they hibernate, affects at least seven species, the researchers said.

It was only identified four years ago, in bats nesting in caves near Albany, New York. Since then, more than 1 million of the flying mammals have died as far afield as Tennessee and Oklahoma.

"The loss of so many bats is basically a terrible experiment in how much these animals matter for insect control," Frick said.

The fungus kills in an insidious way, making the bats restless as they try to hibernate. As they fidget, they burn up their reserves of fat. The researchers estimate that 73 percent of animals in a colony die once the infection reaches them.

"Given the rapid geographic spread of this fungus over the past four years, we can expect that white nose syndrome will adversely affect bat species that form some of largest hibernating bat colonies in the U.S, including two federally listed endangered species that occur mostly in the Midwestern states," Boston University biologist Thomas Kunz said in a statement.

Some research has suggested that people exploring caves have helped spread the fungus so quickly. It also appears to spread from bat to bat, and many regional and local authorities have closed caves to public access when the infection pops up.

Bats appear to have little or no immunity to the cold-loving fungus, called Geomyces destructans, the researchers said. It covers their muzzles and invades their skin, according to the U.S. Fish and Wildlife Service.

"Such a severe population decline, especially if the disease spreads farther south and west of its current distribution in eastern North America, may result in unpredictable changes in ecosystem structure and function," Kunz and Frick's team concluded.

(Editing by Philip Barbara)

'Scary Stuff': Most Common U.S. Bat Headed to Extinction
Stephanie Pappas LiveScience Yahoo News 5 Aug 10;

North America's most common bat, the little brown myotis, will be all but extinct in the northeastern United States in 16 years, thanks to a rapidly-spreading fungal infection, researchers reported Thursday.

The fungus, called white-nose syndrome, grows on the exposed skin of bats as they hibernate in cool caves or mines. The infection causes the bats to wake up from their slumber, depleting valuable fat stores and eventually killing them. If infection continues at current rates, the researchers reported in the journal Science, there is a 99-percent chance the little brown myotis population will drop below 0.01 percent of its current numbers by 2026.

"It's really scary stuff," said Sonia Altizer, an ecology professor at the University of Georgia, who was not involved in the study. "The little brown bat, which is the most common bat species in North America, is being decimated by a single pathogen in a very short period of time."

An underground killer

White-nose syndrome first emerged in New York state in 2006. The fungus has now been confirmed in bat colonies across the northeastern United States and the Canadian provinces of Quebec and Ontario. Bats as far west as Oklahoma and as far south as Tennessee have also been infected. No one knows how the disease came to North America, but humans may have unwittingly carried the fungus from Europe.

Exactly how white-nose syndrome kills and whether some bat species are more vulnerable than others are open questions. What is known is that white-nose is virulent. In some infected caves, 90 percent to 100 percent of bats die, according to the U.S. Fish and Wildlife Service. On average, the disease takes out 73 percent of the bat population at a given hibernation site.

Little brown myotis bats aren't the only bats affected by the disease, but as the most common North American bat, they're particularly important to the ecosystem. To find out how the little brown bat is likely to fare, researchers from Boston University and the University of California Santa Cruz collected data from 30 years of bat surveys taken at 22 caves in the Northeast. They found that before the introduction of white-nose syndrome, little brown bat populations were stable or rising.

Next, the researchers ran computer simulations to test the future effects of the white-nose fungus. They performed 1,000 different simulations, including multiple environmental variables to make the models as realistic as possible.

A dire future

The results were "dire," said Winifred Frick, a postdoctoral researcher affiliated with Boston University and UC Santa Cruz and lead author of the research paper. Even if the white-nose death rate slackens to 10 percent a year, the researchers found, the species will be wiped out from the region within 65 years. The death rate has to drop below 5 percent a year to give the little brown myotis a fighting chance in the next century, Frick said.

The bat's possible extinction is on par with the destruction of the American chestnut tree by a fungal blight in the early 1900s, said Altizer. Once the most common hardwood in the eastern United States, the chestnut all but disappeared within a few decades and has never recovered.

The loss of the little brown myotis and other bats affected by white-nose would be particularly catastrophic for humans, Frick said, because bats eat their body weight in bugs each night. Many of these bugs are agricultural pests or carriers of human disease.

There is still a lot of uncertainty as to the future of the little brown myotis, Frick said, particularly because researchers don't yet understand how population declines from white-nose syndrome will change over time. With such a limited understanding, there is little humans can do to save bats or eradicate the fungus, she said.

"Really, we need more research," Frick said. "We need to study the transmission dynamics to better understand how this is spreading from bat to bat, as well as from site to site ... At this point there's not a silver bullet for a cure."

Bats facing regional extinction from rapidly spreading disease
University of California - Santa Cruz
EurekAlert 5 Aug 10;

SANTA CRUZ, CA -- A new infectious disease spreading rapidly across the northeastern United States has killed millions of bats and is predicted to cause regional extinction of a once-common bat species, according to the findings of a University of California, Santa Cruz researcher.

The disease, white-nose syndrome, first discovered near Albany, N.Y. in 2006, affects hibernating bats and has caused millions to perish, writes lead author Winifred F. Frick, in a study published in the August 6 issue of Science.

Frick, a UC Santa Cruz graduate who is now a post-doctoral researcher in UCSC's Environmental Studies department, said the disease is spreading quickly across the northeastern U.S. and Canada and now affects seven bat species. If death rates and spread continue as they have over the past four years, this disease will likely lead to the regional extinction of the little brown myotis, previously one of the most common species in North America, she said.

"This is one of the worst wildlife crises we've faced," Frick said. "The bat research and conservation communities are trying as hard as possible to find a solution to this devastating problem."

Frick notes that "bats perform valuable ecosystem services that matter for both the environments they live in and have tangible benefits to humans as well. Bats affected by this disease are all insect-eating species, and an individual bat can consume their body weight in insects every night, including some consumption of pest insects," Frick said.

"The loss of so many bats is basically a terrible experiment in how much these animals matter for insect control," she said.

Frick received her BA in environmental studies at UCSC in 1998. She completed her Ph.D. at Oregon State University in 2007 and is currently a National Science Foundation Bioinformatics Postdoctoral Fellow with a joint appointment at UCSC and Boston University. She is also the research director of the Central Coast Bat Research Group in Aptos, Calif.

White-nose syndrome is associated with a newly discovered fungus that grows on the exposed tissues of hibernating bats.

Frick and the study's co-authors, including Jacob F. Pollock, in the department of ecology and evolutionary biology at UCSC, and noted bat experts Thomas H. Kunz and D. Scott Reynolds at Boston University, analyzed bat population data collected over the last 30 years, from 22 caves and other hibernating sites, in five states throughout the northeastern U.S.

The serious population declines of the little brown myotis were recognized based on surveys made by officials from state departments of natural resources going back to 1979. Surveys in the winter of 2006-2007 revealed evidence of white fungal growth on bats' noses, ears, and forearms, aberrant behavior, and an unusually high number of dead bats. As many as 500,000 bats may occupy a single cave.

Decreases in the number of bats counted range from 30 percent to 99 percent compared with earlier counts before the disease struck. Since its discovery four years ago, white-nose syndrome has now been confirmed in at least 115 bat hibernating locations in the U.S. and Canada, and as far west as Oklahoma.

Current research suggests that the fungus disrupts the bats' hibernation, causing them to awake early, behave oddly, and lose critical fat reserves, resulting in death. The researchers predict a "99 percent chance of regional extinction of little brown myotis within the next 16 years" if mortality and spread continue unabated.

"Our results paint a grim picture of a once-healthy population of an abundant and widely distributed species now experiencing unprecedented losses," the authors write.

"The rapid decline of a common bat species from white-nose syndrome draws attention to the need for increased research, monitoring, and management to better understand and combat this invasive wildlife disease," the authors conclude.

The researchers said it is possible the deadly fungus came from Europe from human trade or travel based on evidence that the same fungus has been observed on hibernating bat species in Europe.