White-nose Syndrome: A new threat to New Hampshire's bats
CBS News video (July 2011): Dying bats called No. 1 mammal crisis in U.S.
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What Is White Nose Syndrome?
Hibernating bats are suffering from a new, mostly fatal syndrome called White Nose Syndrome (WNS). It was discovered in the winter of 2006-2007 in four caves in New York. In 2007-2008, WNS spread to caves and mines in New York, Vermont, Massachusetts and Connecticut. New Hampshire has few places for bats to hibernate, so most of our bats hibernate in these other states. In 2008-2009, WNS spread as far as Virginia and up to New Hampshire. Of the seven New Hampshire hibernacula surveyed in 2009, five had WNS. In 2010, WNS spread to Missouri, Oklahoma, Tennessee, Maryland, and Ontario and Quebec, Canada, as well as to additional counties in New Hampshire, Vermont, New York, Pennsylvania, West Virginia and Virginia. 2011 saw further spread east, to Maine and New Brunswick. Midwestern and southern states saw WNS spread – North Carolina, Kentucky, Ohio, Indiana and others all found infected bats. This devastation of 6 species of bats is unprecedented.
Bats in New Hampshire use mines or talus caves to hibernate, but there are few places humid enough for them. In 2009, bat populations in all surveyed mines were higher than in the past two years. It is possible that some bats chose not to fly to Vermont or New York to hibernate due to white-nose syndrome.
Unfortunately, that trend did not continue into 2010. At the second largest hibernacula, the population in 2009 was 982 bats of three species. In 2010 that mine had just 281 bats of only two species, the northern long-eared bats were gone. That is an 83% decline! Overall, the population dropped 70%. In 2011 things were even worse. The second largest hibernacula had only 2 bats. In all surveys, only 30 live bats were found, with one mine being empty. The largest hibernacula was not surveyed, but we got several calls from nearby homeowners that bats were flying in February, all destined to die.
 Researchers take samples of the fungus from the wings of a little brown bat. Photo by Emily Brunkhurst/NHFG |
One bit of good news occurs in two hibernacula that were discovered in 2010. They are in old military bunkers, and there was no sign of WNS. This population, although small, may offer some additional hope. In 2011 the population had doubled, to 114 bats. And the preliminary results from the lab are negative for the fungus that causes WNS. Biologists from NHFG and US Fish and Wildlife Service monitored both the bats and the temperature and humidity in the bunkers, using data loggers placed in several rooms in each bunker. Several bats were banded with unique number bands to see if they return next year. This discovery has led biologists in several other states to look at their bunkers in hopes that controlling temperature and humidity might allow the bats to survive the winter free of WNS<.
We know very little about WNS. We do know that it is characterized by a white fungus that grows on and into the exposed skin of the bats – their muzzles, wings and tail – but only while they are in their hibernacula. The fungus is new to science, and has been appropriately named Geomyces destructans. The bats become emaciated and then some bats come out of hibernation and fly in search of food or water. This means they are flying in the winter, when there is no food and the temperatures are much colder than bats can stand. Many die soon after flying out of the caves and mines, or in the mine itself. Others seek shelter in houses and other buildings to escape the cold temperatures. The white fungus will not be visible on these bats, as bats groom the fungus off before flying. The fungus is not visible in the warmer months at all, as it grows in the cold and damp conditions of the mines where they hibernate, and not in warm locations.A Serious Problem
In several caves in New York and Vermont, up to 99% of bats have died from WNS. WNS seems to have the biggest impact on the little brown bat, which is common in New Hampshire. The Eastern small-footed bat (state endangered in N.H.) has also been affected, as have all cave-hibernating bat species: northern long-eared bats, big brown bats and tricolored bats (also called pipistrelles). Three federally listed species are threatened by WNS, the Indiana bat, which has been killed by WNS, and the Virginia big-eared bat and gray bat, which have not yet, despite having WNS in hibernacula that they use.
We don't yet know what causes WNS, and we don't know what effect losing all these bats might have on our insect populations. Bats eat about half their body weight in insects every night. We don’t know whether they are eating significant numbers of pest insects, but we will find out soon as our skies become devoid of bats and full of insects. Over a dozen research labs, many state and federal agencies, and nongovernmental organization partners are currently studying WNS and trying to learn more about what it is, how it is transmitted, and how to prevent it. The same fungus has been found on an European bats, which is likely the source of this new disease. European bats are not killed by the fungus, however.
 A surveyor wears protective gear so he does not carry the WNS fungus between hibernacula. Photo by Jacques Veilleux. |
The fungus is likely transmitted from bat to bat and between caves and mines by humans. In 2009, the jump from New York to West Virginia and Virginia was a longer distance than bats would be expected to fly. Cavers however, told us that they explored the affected caves in New York, then went to the other states and explored those caves. The fungus does attach to clothing and gear, and thus can be carried to other caves or mines in any season. There are disinfection protocols for gear that have been developed, and can be found on the USFWS website (click here). However, these protocols are not 100% effective, so if you plan on going to an unaffected state to cave, do NOT take your affected gear. Take only clothing and gear that has never been in a cave or mine in the affected states, nor in a cave or mine in Europe. Also, many caves and mines have been closed to prevent transport of this terrible disease. Observe these closures. And stay out of all caves and mines in winter, as your presence will disturb the bats, causing them to wake up and use more precious stored energy.
WNS now appears to be affecting bats during the summer months. Reports of empty barns where bats used to raise babies, empty skies over ponds, and babies being abandoned as the mothers cannot feed them have been coming in to our office and to biologists in other states. You can help by allowing bats to raise babies where they have for years -- in your barn. You can put up a ceiling (even just tacking up a plastic tarp) between your roof and your equipment if you are having problems with the guano in your barn. Bat guano is known as a great fertilizer. Click here for information about bats in your house or bat boxes.
What you can do
If you find dead bats, particularly in a summer colony or several dead bats in the same place in the winter, report it online at www.vtfishandwildlife.com/Sick_Acting_Bat_Citizen_Reporting_Form.cfm. If you can’t report it online, call the Wildlife Division at (603) 271-2461, or email us at wildlife@wildlife.nh.gov. We may want to collect specimens to send to researchers who are studying this disease. Please note: due to the volume of reports we are not able to call or email everyone back. We will call or email if we want to get specimens or need additional information. There is nothing we can do for these bats, unfortunately. DO NOT HANDLE ANY BAT, DEAD OR ALIVE, WITHOUT THICK GLOVES.
If you have bats roosting in your barn or shed and can leave them there so they can breed, that would be very helpful. Click here for more information on solving any issues you might be having in your barn.
If you would like to participate in the statewide summer colony survey, click here. If you would allow a researcher to come study the bats in your barn or shed, please contact the Wildlife Division at wildlife@wildlife.nh.gov.
Stay out of caves and mines in any state from Maine to Missouri and in eastern Canada, and observe cave closings in other states. Follow the USFWS advisories and decontamination protocols found at www.fws.gov/WhiteNoseSyndrome/cavers.html.
Related articles:
- 1/10/2012: Download White-Nose Syndrome Is Killing Our Bats and learn how you can help!
- 04/12/10: Winter Surveys Show White Nose Syndrome Significantly Affecting N.H. Bats
- 07/10/09: White Nose Syndrome Affects N.H. Bats this summer; Peterborough Colony Decimated
For more information on bats in New Hampshire, contact the Wildlife Division at wildlife@wildlife.nh.gov.
