Investigative Workshop: Modeling White Nose Syndrome in Bats
Unraveling the Mystery of White-Nose Syndrome in Bats
The mysterious disease that has killed more than 90 percent of wintering bats in some caves and mines from Vermont to Virginia during the past three years has raised numerous questions about the nature of the disease and how to control it.
Leading experts in the fields of bat physiology, fungal ecology, ecotoxicology, disease and environmental modeling, among others, gathered at a workshop at The National Institute for Mathematical and Biological Synthesis (NIMBioS), June 29-July 1, in Knoxville, Tenn., to explore the disease and to develop solutions to manage it. Representatives from relevant state and federal agencies and other organizations attended.
The affliction has been given the name "White-Nose Syndrome" (WNS) due to its distinctive white fungus growing on the muzzles and other body parts of infected bats. More than a half million bats have died in the past three years due to the disease. Although the cause is unknown, the pathogen is most likely a cold climate fungus. Scientists do not know if the fungus is the sole cause of the bat deaths, or if it is merely an opportunistic pathogen, taking advantage of immune systems weakened by another biological or chemical agent.
It is unclear how WNS spreads, but it is likely transmitted from bat to bat. Other evidence suggests that humans transport the fungus from infected sites to clean sites on clothing and equipment.
The purpose of the meeting was to determine the present knowledge of the disease and to develop predictive models to determine how and under what conditions the disease might spread. Ultimately, the models would be used to help devise appropriate management strategies for controlling it.
Tom Hallam, workshop co-organizer and professor of ecology and evolutionary biology at the University of Tennessee, said so far two management strategies have been proposed to contain the spread of the disease. The first is to eliminate human activity in the caves, which has already been implemented in the eastern U. S. The second proposed management scheme involves heating portions of cave hibernacula to help conserve the bats’ energy reserves during arousals from hibernation so as to discourage the bats from leaving the cave to look for food before the spring. The disease disturbs the bats’ hibernation patterns, thus causing the bat to become severely underweight.
"However, neither of these strategies has been seriously looked at from a scientific point-of-view," Hallam said.
Gary McCracken, workshop co-organizer and professor of ecology and evolutionary biology at the University of Tennessee, said that some bats appear to have a resistance to the disease and that native bats in Europe appear to be immune to it, Both aspects need further investigation, he said.
"It does not kill all species. In affected species, roughly 5-10 percent survive, which is a viable survival rate. Given that there is evidence of resistance to the fungus and that it is not pathogenic to native bats in Europe, the potential exists that its spread is self-limiting,” McCracken said.
Eating up to two-thirds of their body weight in insects over night, bats help keep insects under control, ultimately reducing the quantities of insecticides used on crops. Bats also play an important ecological role in plant pollination and seed dissemination.
In April, the U.S. Forest Service issued an emergency order to close caves and mines in 33 states for up to one year, while scientists work toward learning more about the disease. In 2009, WNS spread south from New England into West Virginia and Virginia and now threatens to spread to the Midwest and Southeast. The Great Smoky Mountains National Park has also closed all its caves to the public, although evidence of the fungus has not been found in the park.
Modeling WNS in Bats at the Individual and Colony Levels: Epizootiology and Management was a NIMBioS Investigative Workshop. NIMBioS Investigative Workshops involve 30-40 participants, of which about half are invited. Individuals with a strong interest in the topic can also apply to attend.
The National Institute for Mathematical and Biological Synthesis (NIMBioS) brings together researchers from around the world to collaborate across disciplinary boundaries to investigate solutions to basic and applied problems in the life sciences. NIMBioS is funded by the National Science Foundation in collaboration with the U.S. Department of Homeland Security and the U.S. Department of Agriculture, with additional support from The University of Tennessee, Knoxville.
For more information, contact Catherine Crawley at 865-974-9350 or ccrawley@nimbios.org
NIMBioS Investigative Workshop: Modeling White Nose Syndrome in Bats
Topic: Modeling White Nose Syndrome in Bats at the Individual and Colony Levels: Epizootiology and Management
Meeting dates: June 29 - July 1, 2009
Organizers: Thomas G. Hallam and Gary F. McCracken (Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville)
Objectives. The epizootiology of White Nose Syndrome (WNS) in bats is best described as partially understood. Indeed, there are uncertainties and questions about the pathogenesis of the disease although it is understood that the fungi Geomyces sp. play a significant role in the onset and progression of the disease. The purpose of this meeting is to develop modeling directions to help assist in the understanding of the temporal and spatial scales, the pathology, and the physiology of bats during WNS stress and ultimately to lead to managed control of the disease.
Summary Report on the NIMBioS Investigative Workshop — Modeling White Nose Syndrome (WNS) in Bats at the Individual, Colony and Regional Levels: Epizootiology and Management
The first NIMBioS Investigative Workshop on White Nose Syndrome in Bats (WNS) convened on June 30 – July 2, 2009 with 37 participants from all over the United States. The participants were a diverse collection of academicians, primarily theoreticians and biologists, with wildlife managers from NGOs and state and federal governments. The focus of the workshop was to understand and mitigate WNS, which is now recognized as the major threat to bats in North America. The workshop was preceded by a webinar held on June 25 featuring 12 speakers who gave background materials necessary for the workshop. The workshop itself consisted of breakout discussion groups that focused on specialized topics and themes, and plenary discussions that focused on the results and mitigation needs. Breakout discussion sessions included modeling and fungi, modeling and bat ecology relevant to WNS, modeling perspectives and utility to WNS, and modeling and management.
Recognitions and recommendations of the workshop included the following:
- Preliminary work has indicated that the pathogen is an exotic fungus, Geomyces destructans; that the epizootic emanated from a point source in a cave near Albany NY; and that the transmission of the WNS is primarily bat-to-bat.
- The disease is at a critical stage in that it has spread rapidly and has disastrous effects on many species of bats.
- A primary concern for managers is the ability to scientifically predict when and where the fungus will next occur, which at present is a “best guess.”
- Management has a strong need for models that can aid in decisions about mitigation of WNS. Identification of onset time of infectivity of the bats in hibernacula is of special concern for remediation actions.
- Properly formulated models can help organize the material, provide directions for experimental work, provide a synthesis of the data, and project testable conclusions about WNS on several temporal and spatial scales. Modeling should be pursued as important components of the WNS analysis and management.
WNS Plans for the Future
Immediate time scale plans include organizing groups of workshop participants to meet a July 31, 2009 deadline for proposals for a special U.S. Fish and Wildlife Service funding initiative on WNS. At this stage no modeling groups have actively pursued funding for WNS research, but with impetus from this workshop, at least one modeling proposal will address this RFP. Another group that has emerged from the workshop is exploring chemical and veterinary intervention to the spread of the disease. Plans were presented to convene a small group of modelers and biologists to organize the modeling efforts for WNS, hopefully through the auspices of NIMBioS. In August, we plan to present a proposal to NIMBioS that will form a working group on WNS. This group will be a select but diverse group including several participants from the workshop.
Organizers: Thomas G. Hallam and Gary F. McCracken (Department of Ecology and Evolutionary Biology, University of Tennessee, Knoxville)
Participants: Ballmann, Anne (USGS NWHC); Bayless, Mylea (Bat Conservation International); Blehert, David (NWHC, Madison); Buckles, Elizabeth (Cornell Univ.); Coleman, Jeremy (USFWS); Cryan, Paul (USGS); Federico, Paula (MBI); Frampton, Wyatt (Utah Dept of Agriculture and Food); Frick, Winifred (Boston Univ.); Hicks, Alan (NYDEC); Holliday, Cory (The Nature Conservacy); Ingersoll, Thomas (Univ. California, Berkeley); Jager, Henriette (ORNL); Knudsen, Guy (Univ. Idaho); Kunz, Thomas (Boston Univ.); Matheny, Brandon (UTK); McCracken, Gary (UTK); Nichols, Jeff (ORNL); Nolfi, Daniel (U.S. National Park Service); Pannkuk, Evan (Arkansas State Univ. ), Peirce, James (Univ. Wisconsin, La Crosse); Post, W. Mac (ORNL); Reeder, DeeAnn (Bucknell Univ.); Robbins, Alison (Tufts Univ.); Saito, Emi (USDA/APHIS/VS/Centers for Epidemiology and Animal Health); Souza, Marcy (UTCVM); Stiver, Bill (U.S. National Park Service); Turmelle, Amy (Univ. Tennessee/CDC); Vulinec, Kevina (Delaware State Univ.); Weinstein, Richard (UTK); White, LeAnn (UFLVetMed); Youngbaer, Peter (Natl. Speleological Soc.)
NIMBioS Investigative Workshops involve 30-40 participants, focus on a broad topic or a set of related topics, attempt to summarize/synthesize the state of the art and identify future directions, and have potential for leading to one or more future
