White Nose Syndrome

Could cave dwelling bat species become extinct in our lifetime?

Wildlife biologists and land managers are alarmed by what many are saying is the most serious threat facing bat populations in human history: Tens of thousands of bats are dying in hibernacula in the northeastern United States and no one knows why. The mysterious affliction, reported in New York, Vermont, Massachusetts and most recently Connecticut, is dubbed “white-nose syndrome” because many affected bats develop prominent halos of white fungus surrounding their faces. White-nose syndrome (WNS) was first reported during the winter of 2006-2007 in a few hibernation caves near Albany, New York, where more than 8,000 bats died. During the winter of 2007-2008, it was reported in at least 18 additional caves and mines in four states. Some biogists put 2008 mortality could be as high as half-million animals that will not be documented until a 2009 census.

Population declines greater than 90% have been documented at the hibernacula where the syndrome was first reported. At least one of the affected species, the Indiana myotis, is protected by the Endangered Species Act. Little brown myotis are sustaining the largest number of deaths, as well as northern myotis. WNS has also been found to infect Eastern small-footed myotis, and eastern pipistrelles. Big brown bats use many of the same caves as the affected species but in far lower numbers. It is unclear yet if this species is also at risk for this plague-like condition. But if so, whatever is ultimately causing this unprecedented die-off of bats appears to indiscriminately kill all cave-dwelling bat species in the Northeastern U.S.

Bats with signs of WNS exhibit fungal growth on their noses and occasionally other parts of their bodies. However, it is becoming clear that not all of the dead or dying bats have obvious visual signs of the fungus. Researchers increasingly suspect the fungus is not the primary cause of the die-offs, but a symptom of a larger, unidentified problem. Making matters worse, it is possible that sick bats are disturbing all bats in the colony causing them to become inappropriately active during hibernation and squandering valuable fat reserves, resulting in the deaths of otherwise-healthy individuals.

On-site reports note that where WNS is present, bats are found to be behaving erratically. Sometimes clustering near cave or mine entrances or other areas where hibernating bats are not normally encountered. Many affected bats have also been seen flying outside their hibernacula during winter, and members of the public are reporting unusually high numbers of dead or dying bats on the landscape near hibernation caves and mines. Similarities between WNS behaviors in bats and those exhibited by honeybees affected by “colony collapse disorder” have been noted.

Leading pathologists from several major laboratories have examined living and dead bats from affected sites and have failed so far to find any obvious pathogens likely to have caused these deaths. The most consistent finding from initial studies of recovered dead bats is that they are emaciated. Their bodies contain little or none of the critical stored fat that bats must have to survive months of winter hibernation.

This has led some researchers to suspect bats are emerging prematurely from hibernation in a desperate search for food. And, that this could be suggestive of chemical interference with hibernation metabolism or of an insufficient availability of food across the late summer/early fall landscapes preventing bats from storing enough fat to last until spring. Extensive spraying of some pesticides or contact with other environmental toxins might be capable of altering bat metabolisms in this manner. Or such contaminants could severely diminish the amount of insect prey availability that bats need before entering hibernation. Northeastern states have experienced a major increase in pesticide use to combat West Nile Virus during the past few years, but any links between this and WNS bat mortalities are unproven.

Researchers seeking answers to the cause of WNS are hamstrung by a profound lack of knowledge about bat population ecology in general, and that of the bats in affected hibernacula specifically. If nothing else, this outbreak will focus attention like never before on the annual movements of bats to and from hibernacula, documentation of their dispersal to summer habitats and their travel corridors, and intensive research into their pre-hibernation foraging and resource needs. As these links in the annual life cycles of bats become better known, natural and anthropogenic factors threatening those links can be discovered, and hopefully corrected, before it’s too late.

Wildlife biologist Al Hicks with the New York State Department of Environmental Conservation notes that WNS appears to have begun in just a small cluster of hibernation caves in New York a year ago, but has since spread across a rapidly expanding zone. If WNS is not stopped, and continues its exponential growth, it has the potential to mushroom with devastating implications to cave-dwelling bats throughout North America.

NOTE: Human health complications from WNS are not suspected. There is no information indicating that people have been affected after exposure to the white fungus. And, it is unclear if there is some pathogen that could be transferred between caves and mines by cave explorers and the biologists studying WNS. Nevertheless, people entering into WNS hibernacula are practicing comprehensive biological contaminant control and respiratory protection measures.

What can you do to help?

The US Fish and Wildlife Service is partners with the Northeastern Cave Conservancy to track movements of cavers who have visited affected sites in New York. If you have visited Knox, Schoharie, Gages or Hailes caves in New York, the conservancy asks you to visit its site to complete a Trip Visitation Form for WNS Study.

Indiana State University Center for North American Bat Research and Conservation has established a fund for research and response activities related to white nose syndrome.

Bat Conservation International has established a Fund for White Nose Syndrome Research. Contributions are encouraged at both sites.

An ongoing discussion about WNS is located in the forums of batmanagement.com and contains some early reports and commentary.

Bob Hoke is scouring the internet for latest WNS information and is maintaining the best collection of links available.

Information on this page was compiled from these sources:
Bat Conservation International and US Fish and Wildlife Service WNS website

Map key: "Confirmed" = Mortality confirmed by state.
"Likely"=Mortality & fungus reported but not confirmed by state.
"Suspicious"= Fungus or other anomaly observed but no mortality at this time. Map graphic: Cal Butchkoski

Little brown bat in a NY cave with obvious WNS.
Photo: Nancy Heaslip

August 2007 NASBAR
White Nose Syndrome Poster

This is the poster created by the NYDEC and presented at the largest gathering of bat professionals in the world during the summer 2007. This was the preview of what was to come, and what no one thought possible.
2 MB file opens with any flavor PDF viewer

February 2008
SBDN-NEBWG
White Nose Syndrome
Presentation Version, Part 1

Presentation Version, Part 2

This was the presentation given by Al Hicks, NYDEC at the largest gathering of bat professionals in the East. This provides the best available information on WNS currently available. Special thanks to Mike Warner and Peter Youngbaer for polishing this version of Al's original presentation. Files are large, please be patient.
Files open in Apple Keynote or Microsoft Powerpoint
File size: 70 MB each

February 2008
SBDN-NEBWG
White Nose Syndrome
PDF Version

I converted Al's presentation into a PDF file to be universally available to everyone. Otherwise identical to the presentation version. File is large, please be patient.
70 MB file opens with any flavor PDF viewer

Aeolus Bat Cave
White Nose Syndrome
Sampling Trip
March 18, 2008

Special thanks to Aeolus video participants:

Scott Darling, Wildlife Biologist VTFW

Christopher Lincoln, VTFW

Ryan Smith, Wildlife Technician VTFW

Susi vonOettingen
Endangered Species Biologist, USFWS

Photography:
Joel Flewelling, Fish and Wildlife Specialist, VTFW

Video editing and webpage:
John Chenger
Bat Conservation and Management, Inc.

VT Fish and Wildlife and USFWS visited this remote White Nose affected site and obtained much needed data on the ongoing mortality event. BCM shipped a DV camera to the VT team at the last minute and Joel Flewelling documented gearing up, bat behavior, data collection, and equipment decontamination. Is this a glimpse of the future of bat surveys in the East?

Anticipating the footage I envisioned just replacing the team's chit-chat audio with a somber music soundtrack. However, listening to the real in-cave audio adds an unexpected dimension. Look for Scott's defeated sighs and attention to the job at hand punctuated by Susi's slightly tensioned voice announcing bats dead or alive to the data recorder. Joel is heard eerily breathing through his respirator while waiting quietly as the camera records hundreds of bats in the final days of life. To witness such an event must be chilling, realizing the magnitude across the four state landscape is downright alarming.
70 MB MOV file opens in QuickTime Player

Aeolus Bat Cave
Smaller format. Identical movie except formatted for iPods and iPhones. If the larger version above drops frames or stutters on your computer during playback, try this version.
38 MB MP4 file opens in QuickTime Player

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