White Nose Syndrome
Could cave dwelling bat species in the eastern US become endangered 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 from New Hampshire to Tennessee, 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. Somebiologists put 2008 mortality could be as high as half-million animals that will not be documented until a 2009 census. In February 2009 WNS sites were confirmed in New Jersey, Pennsylvania, central West Virginia, and southern Virginia. So far in early 2010, eastern Tennessee has been the only major new area reported while other previously reported sites continue to report new counties. By March 2010 WNS was reported on the west side of the Eastern Continental Divide in both NY and WV.
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. This fungus is a previously unreported cold adapted species of Geomyces, a genus of common kinds of soil fungus. 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. However, bats sampled entering hibernation in the fall appear to be perfectly healthy, as do hibernating bats in very early stages of WNS.
Ultimately some researchers 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. It is possible that a Geomyces soil fungus was inadvertently introduced or mutated in the Albany area, and is now virtually uncontrollable as it feeds on the exposed skin membranes of bats in certain underground environments. The fungus infection progressively irritates bats in hibernation forcing more frequent arousals until the bats simply starve to death. Bat mortality continues into June even after the survivors have fled the hibernaculum. Why some bats continue to succumb to to WNS in good weather with plenty of food availability is not understood, but suggests that something else other than the presence of a fungus irritant could be to blame. Wildlife rehabilitators with experience solving fungus problems suggest long treatment periods are necessary to fully eradicate some types of fungus, so it is easily conceivable the fungus infection deteriorates the wing membranes of bats well into spring effectively grounding and ultimately killing them even in good weather.
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.
While the mechanism of transmission is still unknown, the rapid dispersal of WNS from a single New York cave in 2006 to numerous sites in contiguous northeastern states by 2008 suggests that WNS is likely spread through direct bat-to-bat and bat-to-cave contact. Bats are likely the primary vector for WNS based on the rate of spread through 2008 and the behavior of the species affected. There is mounting evidence, however, that human activity may also be responsible for spreading the causative agent(s) of WNS, even during seasons when bats are not occupying caves. The fungus can grow on many different organic materials, and appears to persist in caves and mines year-round. Fungal spores, and/or other microscopic organisms, can easily become attached to skin, hair, clothing and equipment, and it is possible that such elements could remain viable for weeks or months after leaving a subterranean environment. The discontinuous nature of the rapid spread of WNS, especially to the most recently discovered sites in West Virginia and southern Virginia, suggests that something other than bat-to-bat transmission is contributing to the spread of WNS. The potential for the human-assisted spread of WNS is further supported by the fact that many of the recently affected sites are also popular destinations for recreational cavers, while many bat hibernacula in less-popular or inaccessible caves between the newly affected caves and those affected in 2008 remain unaffected. Records of caver movements also reveal a connection between sites in these affected regions, additionally suggestive of a link to human activity. 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. Migrating bats caught in the right cold snap theoretically could have fungus problems (if fungus is the causative agent). Red bats are just recently known to hibernate in leaf litter under snow, so it is possible that even non-cave dwelling bats could be at risk.
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 has partnered 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.
The US Fish and Wildlife Service now recommends suspending activities in caves in a last hope effort to slow the spread of WNS across the country. This is in addition to the decon protocol that was already in place.
Bat Conservation International has established a Fund for White Nose Syndrome Research. Contributions are encouraged at both sites.
The Vermont Chapter of the Nature Conservancy has an excellent web site with trip reports and photos of the dire situation at their bat caves in VT.
Bob Hoke is scouring the internet for WNS information and is maintaining some of the best collection of links available.
The FWS is hosting a blog with trip reports and other tidbits.
By March 2010, WNS was found on the west side of the Allegheny Front, or Eastern Continental Divide. With this geographical hurdle cleared, it will slowly march west in the coming seasons. There is probably a lag time of years between when a site is affected and when bats are observed dropping dead. Therefore numerous other sites and states are likely affected but will not be observed for several years. Map graphic: Cal Butchkoski
Distribution of WNS-affected counties, known bat hibernacula and bat species. (PDF 2.78 MB)
Map courtesy of Zac Wilson, Bat Conservation International
Little brown bat in Mifflin County, Pennsylvania with obvious WNS. Photo: John Chenger, Bat Conservation and Management
Updated Information on White Nose Syndrome
Seeing bats this winter in Pennsylvania?
Report sick bats to the PGC and help track WNS spread!
(~3 or more bats December thru May)
August 2007 NASBAR
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
White Nose Syndrome
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 available at that time. Information has since exploded so this PDF does not necessarily represent up-to-date information. Special thanks to Mike Warner and Peter Youngbaer for polishing this version of Al's original presentation.
70 MB file opens with any flavor PDF viewer
Breaking WNS news and generous doses of wild speculation is located in the BCM WNS Forum
The National Speleological Society is maintaining an excellent archive of WNS news and information
The US Fish and Wildlife Service recommended protocols to decontaminate caving gear. Use -different- gear when visiting outside of your local caving area in additional to decon protocols to help slow the spread of WNS.
Aeolus Bat Cave, Vermont
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.
Participants: Scott Darling, VTFW; Christopher Lincoln, VTFW; Ryan Smith, VTFW; Susi vonOettingen, USFWS.
Photography: Joel Flewelling, VTFW.
Editing: John Chenger, Bat Conservation and Management, Inc.
Run time: 5:51;Dimensions: 960x540; Size: 70 MB MOV QuickTime file
White Nose Syndrome Sampling Trip HD Video
March 18, 2008
What's Killing The Bats?
Click Here to view CBS video
Bats play a crucial role in maintaining the balance of nature and they're dying in record numbers in several U.S. states. As Daniel Sieberg reports, it's a mystery that has biologists baffled. Aeolus Cave visited February 2009, segment aired April 5, 2009. Additional footage is available below.
CBS News graciously released the raw footage from the February visit, including footage "too gruesome for television." BCM edited the footage into a mini documentary of sorts. In some places the dead bats on the floor are estimated at 300 per square foot. Viewer discretion advised. These are not actors, their reaction upon entering the cave is genuine.
Participants: Scott Darling, VTFW; Joel Flewelling, VTFW; Alan Hicks, NY DEC; David McDevitt, TNC; Rose Paul, TNC; Ryan Smith, VTFW; Daniel Sieberg, CBS News; Alison Whitlock, USFWS. Photography: Eric Teed, CBS News.
Editing: John Chenger, BCM, Inc. Special thanks: Jack Renaud, CBS News
Run time: 15:12; Dimensions: 480x360; Size: 112 MB .m4v QuickTime file
Shindle Iron Mine, Pennsylvania
One of the first WNS sites confirmed in Pennsylvania
White Nose Syndrome Sampling Trip
January 29, 2009
Photo essay of the first confirmed White Nose Syndrome site in Pennsylvania
White Nose Syndrome Sampling Trip
January 29, 2009
HD video underground Mifflin County, PA during a midwinter WNS investigation trip by the PA Game Commission, Bat Conservation and Management, and Bucknell University.
Run time: 5:39; Dimensions: 960x540; Size: 158 MB m4v QuickTime file
Joe Kosack, PGC January 2009
Run time: 2:28; Dimensions: 640x360; Size: 18 MB wmv
If movies do not play, make sure to upgrade your free QuickTime software!!!! Movies stream or "right-click" them to save to your hard drive for better performance.
Tresckow Mine, Pennsylvania
One of innumerable mine shafts in northeastern PA with massive WNS mortality.
Tresckow WNS Emergence
January 31, 2010. A steady stream of bats emerge from this mine on a cold day in January 3 months early and die. Some images may be considered graphic.
File: 109M; image: 1280x720
Tresckow WNS Emergence
February 5, 2010. A warmer day; more bats are witnessed airborne, roosting under rocks, dying on the sides of trees. At least a thousand are dead within a few hundred feet of the entrance, and the mine air now smells of dead animals.
Some images may be considered graphic.
File: 164M; image: 1280x720
March 2012. Local ABC Channel 16 WNEP Pennsylvania Outdoor Life.
Video revisiting a cave that was first explored back in 2010 to see how the effects of White Nose Syndrome have effected the local bat population.
A collection of snapshots documenting the decimation of winter hibernacula
Mt. Aeolus Cave, VT; Aitkin Cave, PA; Sewra Cave, PA; Dunmore Anthracite Mine, PA; and Barton Hill Mine, NY