The Alabama Bat Working Group will have its spring meeting at the Wheeler National Wildlife Refuge Visitors Center in the Decatur area on May 2, 2013 at 10:00 a.m. Topics will include the results of winter White-nose syndrome surveys, planned summer surveys and monitoring, and reports from subcommittees on ongoing work. If you have an interest in bat and/or bat habitat (caves/karst) conservation and management in Alabama you will not want to miss it! This includes those who would like to learn more about this valuable natural resource. We look forward to meeting you!
TVA has announced that Geomyces destructans (Gd), the fungus that causes White-nose syndrome (WNS), was found on swabs from gray and tricolored bats in Collier Cave in Lauderdale County, Alabama. Below is their recent announcement.
“White-nose Syndrome Detected in TVA Cave in Alabama
KNOXVILLE, Tenn. ― The fast-spreading fungus that causes the deadly white- nose syndrome in bats has been found in Collier Cave in northwestern Alabama on property managed by the Tennessee Valley Authority.
“This occurrence marks the first reporting of white-nose in Lauderdale County and the farthest west the disease has been found in Alabama,” said TVA terrestrial zoologist Liz Burton. “This is the second TVA cave with positive findings of the fungus.”
TVA has been working since 2009 with the U.S. Fish and Wildlife Service and statewide teams to develop white-nose syndrome response plans for Tennessee and Alabama, and to collaboratively address the disease across the Southeast. As part of that effort, TVA has closed public access to all caves, sinkholes, tunnels and mines on TVA-managed lands due to concerns that human contact may spread the disease from cave to cave. Since its discovery in 2006 in New York State, white-nose syndrome has been confirmed in 22 states as far west as Missouri and Illinois, and most recently in South Carolina and Georgia, and blamed for the deaths of more than 6 million bats.
Alabama’s first confirmed case was in the winter of 2011-2012, the same season the first infected TVA cave was discovered at Norris Dam Cave near Knoxville. The number of infected caves in Tennessee has more than doubled since a dozen caves were identified a year ago.
“It is likely that future monitoring efforts will reveal further spread of white-nose syndrome in the Tennessee Valley,” Burton said.
Swab samples taken by TVA biologists in 2012 of two bats in Collier Cave tested positive for the fungus after they were re-checked in March 2013 using more sensitive techniques. One bat was a federally endangered gray bat; the other was a tri-colored bat. Neither showed visible signs of the disease, there was no visible mortality at the site, and census numbers were similar to previous years.
In many caves where the disease has been present for several years, mortality rates over 90 percent have been documented. Research suggests that the fungus ─ which often grows into white tufts on the muzzles of infected bats, giving the disease its name ─ may cause a suite of physiological problems. These include wing tissue damage, alteration of circulation and respiratory function, and dehydration. These physiological
disturbances can lead to more frequent arousal during hibernation. “There is no known treatment for the disease or known way to completely stop the fungus from spreading,” Burton said. “The chosen paths forward are to restrict access to caves, monitor the spread, and continue researching exactly how the disease works.”
For more information, see the national white-nose syndrome website at http://whitenosesyndrome.org/ or contact the TVA Environmental Information Center at http://www.tva.gov/environment/eic/ or call 800-822-5263.
Bats play a critical role in the ecosystem by controlling insects, pollinating plants and providing food for other animals. TVA’s work with others to protect caves and monitor numerous gray bat populations is one of TVA’s primary environmental stewardship activities. The Tennessee Valley Authority is a corporate agency of the United States that provides electricity for business customers and local power distributors serving 9 million people in parts of seven southeastern states. TVA receives no taxpayer funding, deriving virtually all of its revenues from sales of electricity. In addition to operating and investing its revenues in its electric system, TVA provides flood control, navigation and land management for the Tennessee River system and assists local power companies and state and local governments with economic development and job creation.”
Note that this does not confirm the presence of WNS in bats in Collier Cave. Only the skin invasion by Gd can confirm the presence of WNS. However, this information does make these species of bats “Suspect” for WNS in this cave.
WNS was first discovered in tricolored bats (Perimyotis subflavus) in Russell Cave in Jackson County, Alabama, in February 2012. In early 2013 the disease was confirmed in this same species in Fern Cave, also in Jackson County. In both cases, tricolored bats were confirmed to have WNS by the lab of the Southeastern Wildlife Disease Study located on the campus of the University of Georgia in Athens. Gray bats (Myotis grisescens) from Fern Cave appear to be carrying the fungus that causes WNS – Geomyces destructans (Gd). Five gray bats, including three live and two carcasses, were found to be Polymerase Chanin Reaction (PCR) positive, which indicates the presence of the genetic signature of Gd. However, four gray bat carcasses were collected in total and none had the skin invasion by the Gd which confirms the disease in bats. Thus, gray bats in Alabama are not known to be infected with the disease at this time.
Photos taken of tricolored bats by cavers in two other caves in Jackson County in early 2013 have the visual signs of WNS. However, specimens would have to be collected and tested before it could be determined for sure if bats in these caves are carriers or infected.
The current theory is that Gd begins skin invasion while bats are in torpor (similar to hibernation). Bats in torpor reduce the activity of many body functions including that of their immune system to conserve energy. This allows them to survive the winter on the fat deposits they put on eating available insects in summer and fall. The process of skin invasion by Gd irritates bats and they awaken more often during the period they are in torpor (often this is described as the hibernation period or season, but bats are not truly in hibernation because they normally awaken some during this season). Awakening from torpor requires the bats to expend energy. Over this wintering period the bats end up using all of their fat deposits prior to the end of winter. Bats begin to move toward cave entrances and have been observed numerous times further north flying around in the late winter. It is believed they are searching for insects because they have used up their fat reserves. Insects are not normally available at this time and the bats end up dying on the landscape, likely from starvation.
WNS may take more than one year to begin causing mortality of bats. It is not known at this time if bats in southern areas, like Alabama, will begin dying in the numbers seen further north. However, they could begin flying outside of infected caves in late winter in future years, perhaps as early as 2014. If it happens, it will likely occur around Jackson County first since the disease is spreading there.
Bats are not known to have the illness during the summer, although they may be carrying the spores (reproductive bodies produced by the fungus while it is growing on the bats in the winter) and show signs of wing damage. Sick bats during warmer periods of the year may be suffering from other illnesses, such as rabies. Sick bats observed outside caves during the winter may be impacted by WNS.
People who find sick bats should not handle them unless they have been vaccinated for rabies! If found during the winter or early spring, check the bats for signs of a white fuzz on exposed skin that you can see without handling them. Typical locations are around the nose, on the wings (including the forearms), and on the feet. Take photos if possible. Report the incident on this website. Be sure to provide information on the date, location, weather conditions, the size and color of the bat, whether the white fuzz was present, and other unusual conditions. Indicate whether you have photos available and your contact information. Having an e-mail address is handy should an Alabama Bat Working Group (ABWG) member need to contact you.
Members of the ABWG do not have the resources to investigate all incidences of sick or dead bats that may be observed. This will be even more true as WNS spreads if it causes a similar amount of mortality as in states further north. However, reports by the public may prove very important in helping us track the spread of this disease in Alabama and may help us determine where limited resources should be utilized to check bats for WNS in their wintering caves.
County or city health departments may be contacted if sick bats are found during the spring, summer, and fall to determine if they would like to test the bats for rabies. However, only someone with rabies vaccinations should handle the bats! Otherwise, you may be exposed to rabies.
The ABWG is composed of individuals interested in bat conservation and management. Members come from several state and federal agencies (for example, the Alabama Department of Conservation and Natural Resources, U.S. Fish and Wildlife Service, U.S. Forest Service, U.S. Department of Agriculture – Wildlife Services, and National Park Service), private non-profit groups (e.g., several grottos of the National Speleological Society and the Southeastern Cave Conservancy, Inc.), and interested members of the public. Please join us if you are interested in helping conserve and manage Alabama’s important bat populations. We typically have two meetings each year. The next meeting is to be held at the Wheeler National Wildlife Refuge Visitors Center in Decatur on Thursday, May 2, 2013 at 10:00 a.m.
Below is an article about WNS being found in Fern Cave in Jackson County, Alabama. It is verbatim from the U.S. Fish and Wildlife Service website at http://www.fws.gov/refuges/news/White-noseSyndromeFernCaveRefuge.html.
“The U.S. Fish and Wildlife Service has confirmed the presence of white-nose syndrome at Fern Cave National Wildlife Refuge in Jackson County, Alabama. Fern Cave provides winter hibernation habitat for several bat species, and contains the largest documented wintering colony of federally listed endangered gray bats, with over one million gray bats hibernating there. The disease was confirmed in tri-colored bats that were collected at two entrances to the cave.
White-nose syndrome (WNS) has decimated bat populations across eastern North America, with mortality rates reaching up to 100 percent at some sites. First documented in New York in 2006/2007, the disease has spread into 22 states and five Canadian provinces. Bats with WNS may exhibit unusual behavior during cold winter months, including flying outside during the day and clustering near the entrances of caves and mines where they hibernate. Bats have been found sick and dying in unprecedented numbers near affected sites.
White-nose syndrome has been documented in seven hibernating bat species, including two federally listed endangered species, the Indiana bat andgray bat.
Single Most Significant Hibernaculum for Gray Bats
“With over a million hibernating gray bats, Fern Cave is undoubtedly the single most significant hibernaculum for the species,” said Paul McKenzie, endangered species coordinator for the Service. “Although mass mortality of gray bats has not yet been confirmed from any WNS-infected caves in which the species hibernates, the documentation of the disease from Fern Cave is extremely alarming and could be catastrophic. The discovery of WNS on a national wildlife refuge only highlights the continued need for coordination and collaboration with partners in addressing this devastating disease.”
The infected tri-colored bats were discovered on winter surveillance trips, conducted by the U.S. Fish and Wildlife Service and members of theNational Speleological Society (NSS) and Southeastern Cave Conservancy, Inc. (SCCi). Biologists observed white fungus on the muzzles, wings and tail membranes of several tri-colored bats, leading them to collect specimens for analysis.
Impact on Gray Bats Still Unknown
The gray bat, federally listed as an endangered species in 1976, occupies a limited geographic range in limestone karst areas of the southeastern United States. With rare exceptions, gray bats live in caves year-round. Gray bats live in very large numbers in only a few caves, making them extremely vulnerable to disturbance. Cooperative conservation measures, such as restricting human access to gray bat roosting sites, have been successful in helping gray bat populations recover in many areas. The potential impact of WNS on gray bats is still unknown.
Fern Cave Refuge consists of 199 acres of forested hillside above a massive cave with many stalactite and stalagmite-filled rooms. The cave has five hidden entrances, four on the refuge. One entrance is owned and managed by SCCi. Access is extremely difficult and has been described as “a vertical and horizontal maze” by expert cavers. Horizontal sections of the cave are known to be more than 15 miles long and vertical drops of 450 feet are found within. The partnership with NSS and SCCi has been critical to monitoring the gray bat population at Fern Cave.
The Service is leading a cooperative effort with federal and state agencies, tribes, researchers, universities and other non-government organizations to understand and manage the spread of WNS. While bat-to-bat transmission is presumed to be the primary method of spreading the disease, scientists believe that humans can inadvertently transport fungal spores on clothing, footwear, and gear that has been in infected sites. Fern Cave is not open to the general public and the entrances on the refuge are closed to protect gray bats. Researchers and permitted cavers entering Fern Cave take great care to reduce the risk of transporting fungus into or out of the cave, and minimize disturbance of roosting bats.
Cave explorers and researchers should check with the appropriate land manager before visiting any cave, as many caves are closed to protect hibernating bats. Decontamination of clothing, footwear and gear can reduce risk of accidental transmission of fungal spores. For the most up-to-date decontamination protocols, please visit the national WNS Web site.”
The photo below is one of the tricolored bats affected by WNS in Fern Cave.
Photo copyright Darwin Brack