Little brown bat
Has the NWTF gone batty?
Turkeys don't live in caves but share the same "above ground" habitat necessary for bats and birds to survive
Bats may be one of the least cuddly creatures in nature's menagerie, but they play an important role in how the world works.
That's why a mysterious fungus affecting bats is causing alarm. White-nose syndrome, so named because it grows on bats' faces, doesn't kill them, but disturbs their sleep and ends their hibernation early. They wake up too soon and start looking for food when there isn't any.
The disease, for which there is no cure, was first spotted in New York State in 2006. From there, it spread to New England and has quickly moved south and west, crossing the Mississippi. Last year, the fungus crept into Alabama and in February made its way into upstate South Carolina.
In just six short years, more than 5.5 million hibernating bats have died in at least 21 states and five Canadian provinces. Truth be told, the death toll is much higher. How much is unknown.
Some of the worst hit areas have experienced 90 percent mortality. The fungus is causing bats to starve by the thousands, placing rare species in danger of extinction. More common species also are severely threatened. A 2010 study in the Journal of Science predicted the little brown bat — once prevalent in North America — may disappear from the eastern United States within 16 years.
The disease shows no signs of slowing, and experts suspect that none of the country's 25 hibernating bat varieties are immune.
How it affects you, turkeys
White-nose syndrome doesn't harm humans, but it may affect their pocketbooks if the epidemic continues to kill bats that eat insects in great numbers. One study suggests the cost to farmers will reach the billions, raising produce prices around the globe.
Government agencies, research scientists and conservation groups quickly turned their attention to white-nose syndrome when it first appeared in the United States, but bats have low reproductive rates, so recovery from losses is slow. Bats once common are becoming rare, and rare varieties are dwindling faster than expected.
With that in mind, the NWTF struck a partnership with Bat Conservation International in 2009.
"Partnering with conservation organizations like the NWTF extends our message to people who might otherwise not hear about BCI and our mission," said bat conservation biologist Mylea L. Bayless. "The NWTF maintains excellent relationships with private landowners, and we look forward to learning from their success and challenges. Through our combined efforts, we can provide a more comprehensive voice for conservation."
Combined efforts will also impact on-the-ground work that benefits bats and turkeys.
"The NWTF entered into a partnership with BCI because bat and turkey management is mutually beneficial," said Mark Hatfield, NWTF director of eastern conservation planning. "We share the same habitat management practices with slightly different results. Bats and turkeys occupy different niches within the same area, so any work we do as a partnership will help both species."
Turkeys benefit from better places to nest, eat and raise broods.
Up to bat
It's difficult to wrap our brains around 1 million of anything, let alone 6.5 million — the latest bat mortality numbers released by the U.S. Fish and Wildlife Service. It's even harder with something as mysterious as a hibernating bat, especially since hundreds of thousands of their caves have never been explored. Giant strides have been made, however, including what causes white-nose syndrome.
David Blehert and colleagues at the U.S. Geological Survey identified the culprit as a previously unknown fungus from soil. Bats that do not hibernate haven't been affected, probably because hibernating bats have lower metabolisms and body temperatures, and their densely packed sleeping habits allow the fungus to spread easily.
Experts suspect that people who explore caves unwittingly carried the fungus to the United States from Europe but can't be entirely sure. Many caves in the eastern part of the country — all those on public land in Tennessee, for instance — have been closed to humans, but the fungus still spreads, suggesting that bats may carry it, instead, says Dr. Jeff Foster, a wildlife disease ecologist at Northern Arizona University.
Researchers have found that bats in cooler conditions may have better survival rates. So it's possible that humans can alter the temperatures in some mines by changing the shape of entrances to direct airflow, for instance.
In Tennessee, conservationists have built an artificial cave that can be kept fungus-free, and in New Hampshire, biologists are studying bats that hibernate in abandoned World War II-era bunkers, hoping that climate conditions inside will help some bats survive. The National Zoo has attempted to keep endangered Virginia big-eared bats alive in captivity, but with limited success.
Wildlife experts reported from a recent white-nose syndrome symposium:
- Some bats banded in studies survive several years after an infection, raising hopes that the syndrome isn't inevitably deadly.
- Several bat species, including Virginia big-eared bats, do not seem to decline in great numbers when infected.
So far, cases in Alabama, Indiana, Kentucky, Tennessee and Missouri have not produced the huge die-offs of bat colonies common in Northeastern caves, prompting researchers to question why. One answer might be that differences in cave humidity levels or shorter hibernation times may prevent the fungus from wreaking as much havoc on bats in temperate states,
Scientists across North America are searching desperately for solutions, but they have found no way to cure white-nose syndrome or to slow its relentless advance. Many advocate declaring white-nose syndrome an invasive fungus species, which would likely increase money to fight it.
"We don't know what the future holds for bats in North America," said Nina Fascione, former executive director of Bat Conservation International. "But we will continue trying to find a solution." — Chasiti Kirkland