Big Problems for Little Bats Mysterious Disease Threatens Species and Environment BY EMILY ATKIN
W
Photo provided by mytimesdispatch.com
inter is approaching, and with it
solely in hibernating Myotis lucifungus—that is,
a serious epidemic is growing.
little brown bats.
Since 2006, a strange disease has
White Nose Syndrome, or WNS, is named for the
been spreading across the northeast, showing
white fungus found on the ears, muzzles, and wings
itself in New York, Massachusetts, Pennsylvania,
of infected bats. It was first discovered by cavers in
Connecticut, and several other states. The disease,
the winter of 2006 in Howes Caverns near Albany,
called White Nose Syndrome, has already claimed
N.Y. According the U.S. Geological Survey, it has
over 400,000 lives, and has shown no signs of
since been found in eight more northeastern states.
stopping. Its symptoms are unique, and the cause
The disease threatens the already endangered
is unknown. But humans need not worry about
Indiana bat (Myotis sodalis), and the Virginia Big
contracting White Nose Syndrome, for it is found
Ear bat (Corynorhinus townsendii virginianus), as
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Photo provided by www.fort.usgs.gov/WNS/
well as several other species of fruit and insect eating bats. It is not hard to see why White Nose Syndrome is a problem. Bats, like bees, play an essential role in seed dissemination and pollination. Bats provide food for owls, hawks, raccoons, and other animals. They help maintain cave ecosystems, and are the leaders in nocturnal insect control. Bats consume over half their body weight in mosquitoes and moths every night, reducing the need for insecticides and
“
Hibernation is cut short because they’re hungry. They come out to eat and immediately freeze.” —Michael Boms Professor of Biology at SUNY New Paltz
making summer less annoying for everyone. But getting rid of the disease won’t be easy, according to the National Wildlife Health Center. According to the Center, bats are used to having a high survival rate, and usually produce no more than one pup per year. Because of this lack of reproduction, and because bat populations do not fluctuate widely over time, it is unlikely that bat species affected by WNS will recover. Even after three years of disease spread, The Fish and Wildlife Service (FWS) has not formed hypotheses as to why the fungus is occurring. Additionally, scientists at the FWS are boggled as to why the bats are dying from the disease. According to Michael Boms, Professor of Biology and Animal life at SUNY New Paltz, bats with WNS show no signs of actually dying from the fungus itself. Instead, they are freezing to death. “It seems to be because of fat depletion,” explained Boms. “Hibernation is cut short because they’re hungry.
A hibernating Myotis lucifungus, heavily infected with White Nose Syndrome.
They come out to eat and immediately freeze.” The part that is puzzling is the reason for the early hunger pains. Though it is proven that fat depletion is a direct result of the fungus, scientists can’t figure out the specific reason why. Bats with WNS also exhibit strange behavior. The FWS issued a statement noting that infected bats will fly around midday in the wintertime. Professor Boms added another example. “Caves are perfect for hibernation, because they stay warm yearround,” said Boms. “Bats usually hibernate at the back of the caves, where it’s warm. But cavers have been finding bats hibernating at the entrance.”
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Maps provided by www.fort.usgs.gov/WNS/
Maps illustrating the overlapping ranges of non-hibernating (left) and hibernating (right) species of U.S. bats.
Map illustrating the ranges of endangered species of hibernating bats in the U.S. and the spreading distribution of White Nose Syndrome (WNS).
Images provided by emnrd.state.nm.us
Cavers, the original discoverers of WNS, could be the reason for the rapid spread. Though it has been proven by the FWS that the disease can be spread from bat to bat, it does not explain why the disease cannot be contained. According the National Speleological Society (NSS), the pattern of disease spread suggests that humans are also transporters from infected sites to clean ones. This most likely happens when cavers get fungus spores on their clothes and equipment and do not decontaminate them between cave visi visits.
Ecological effects may already be taking place. According to an article done by the New York Times, mosquito levels were three to five times their normal level in the Hudson Valley this year. In a statement to the Times, Dr. Michael C. Caldwell, Dutchess County Health commissioner, said that the levels were “the worst I’ve seen in my fifteen years as commissioner.” According to Professor Boms, however, this finding could or could not be because of White Nose Syndrome. “It’s a good possibility,” said Boms, “but we have to look at other alternatives.” Boms explained that the increase in mosquitoes could also be because of the excess rain this summer— not because of WNS. According to Boms, in order to accurately determine whether or not White Nose is the cause, the study done by the health commissioner would have to be repeated during a dry season. Scientists are doing all they can to make sure that ecological consequences do not occur. But it is difficult in the summertime, when bats do not hibernate. The deadly effects of White Nose Syndrome are exclusive to the winter, so studies have to be kept on hold until then. But even though research has to take a back seat, other types of action are sitting up front. The NSS is a good example. According to a statement issued to all members, the NSS is focusing on “developing science and management strategies, pursuing research funding, and performing summer maternity colony and acoustical monitoring surveys.”
Eptesicus fuscus Big brown bat
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Myotis lucifungis Little brown bat
Photo provided by morethangray.com
The statement, however, also warned of the danger of the disease spread. “In the northeast, where WNS has ravaged bat populations for three winters, reports came in of devastated maternity colonies and almost no signs of affected species in the night skies or in mist nets. In Peterborough, N.H., a 16-year longitudinal study of Myotis lucifungus (little brown bats) came to an end after the entire bat population disappeared. In Strafford, Vt., an annual mist net survey that normally captured 900 bats caught one. The New York acoustical monitoring project found so few bats of hibernating species that NYDEC is planning to file to add the Little Brown Bat and others on the state’s Endangered Species List.”
How YOU Can Help Protect Bats!
In other words, things are not looking good. So what can you do? According to the FWS, if you see any dead bats on the ground or in trees or buildings, contact your state wildlife agency, or e-mail the U.S. Fish and Wildlife Service biologists at WhiteNoseBats@fws.gov. You can donate to the WNS fund by visiting caves.org/WNS, and make sure your caver friends know about proper equipment decontamination procedures. But most of the solution lies in the scientists and researchers. They still need to determine the origin on the WNS fungus. They will need to determine the ecological consequences of a large-scale bat extinction. They will need to develop strategies on how to control WNS. And they will need to find out if the disease affects all bats, or if any are resistant. There is much to be done. The question is, will there be enough time to do it all?
FIRST, eliminate use of pesticides! Pesticides not only harm you, but our bat friends as well! SECOND, if you have a bat colony in your attic, rejoice, and do not panic! Exclude the bats instead of killing them, and set up a bat house near your chimney instead. THIRD, go outside at dusk and watch the bats flying around catching insects. Teach your children not to be afraid of them, but to value them as a vital part of our ecosystem.
Corynorhinus orhinus townsendii virginianus Virginia a Big Ear Bat
Myotis tis Sodalis Indiana na bat
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Images provided by emnrd.state.nm.us
These tips and more can be found at www.state.nj.us.