WNS was discovered about a year and half ago, and the US Fish and Wildlife Service and New York Department of Environmental Conservation have done a great job of involving researchers from a variety of disciplines and locations. Mycologists, virologists, toxicologists, immunologists, physiologists, ecologists, and pathologists (and this is surely only a partial list) have been enlisted to try to find either the cause or a solution to WNS. Likewise, there are researchers working on the problem throughout the Northeast, as well as in Wisconsin, Indiana, Colorado, California, and Canada. I won’t venture a guess as to how many researchers and land managers are involved, but it’s safe to say that this is a very large collaborative effort.

Much of the research to date has focused on identifying the geographic scope of WNS and determining the pathogen causing the symptoms (if there even is a pathogen). A lot of work has been done on both fronts, but many questions remain unanswered. Affected caves have been found in New York, Massachusetts and Vermont, and a few caves in Pennsylvania are suspicious; however, I am wary of using affected caves to determine the geographic scope of the problem because these bats are migratory and will spread out over the entire Northeast this summer. Further, affected caves are being identified by conspicuous fungal growth on the bats, but we still do not know if this is a universal indicator of WNS. The pathology work is also a little inconclusive. Several species of fungi have been identified growing on the bats, but none have been directly implicated for actually killing the bats.

Several other projects were also conducted last winter. My involvement with this project has revolved around determining the energetic consequences of WNS. We know affected bats are prematurely running out of energy, but we still do not know why. We used thermal imaging cameras to determine if bats were hibernating differently than bats in unaffected caves. Affected bats do not appear to be doing anything different during hibernation, but we did find that they are not responding normally to disturbance, which is likely because of a lack of energy. During our trips into the caves, Marianne Moore from Boston University was also taking blood from hibernating bats to test the immune responses of affected and unaffected individuals.

The hibernation season is essentially over in the Northeast, so much of the in-field research has ended for the year. However, labs around the country are continuing the search for the cause of WNS. The next step is determining what research needs to be conducted and how projects should be prioritized for the upcoming winter. To this end, researchers will be meeting in New York this June to discuss what is known, what needs to be done, and where funding can be obtained to conduct the necessary research. Bat Conservation International is one of the sponsoring groups for this meeting, and donations to their WNS fund will help defray the travel costs of getting all of the relevant experts to the meeting. If you are interested in donating funds to be used specifically for research of WNS, Indiana State University’s Center for North American Bat Research and Conservation has started a fund as well.

We don’t know exactly how many bats will die this year, but we are increasingly confident that we will see a population crash in bats in the northeast. As a biologist working on bats, I have academic and scientific reasons to worry about such a population crash, but many of the researchers involved with studying this die-off (including me) have been asked why the public should be concerned. The sheer complexity of the ecosystems involved and the understudied role of bats in the ecosystem make it difficult to know exactly what to expect, but I will try my best to summarize some of the possibilities below. I do want to emphasize that we have never seen a population decline of the magnitude we expect to see this year, so even those of us studying bats can only guess what will happen.

All of the bats in the Northeast are insectivorous (they eat only insects). They consume huge numbers of insects each night during the summer including crop and agriculture pests, various swarming insects, moths, and even the occasional mosquito (but mosquitoes are not a large part of their diet as is sometimes claimed). What exactly will happen when all of these insect populations are released from their main predator is unknown. The standard answer that we bat biologists give the media is that we should expect an increase in all of these insects—especially, it often seems, the ones that cause the most harm to humans. Unfortunately, this “sound bite” type answer doesn’t really do justice to the scope of the problem.

The latest and greatest ecological theory would predict that some species of insects, but probably not all, will experience population increases. Some species will do better than others, either because they reproduce more quickly or because they are better competitors for food. This will lead to a change in the composition of the insect communities in addition to an increase in their overall numbers. Changes in the insect communities may trickle down and lead to changes in the plant communities; changes in the plant communities may affect herbivore communities; changes in herbivores may affect carnivore communities; and so on throughout the entire food web (ecologists call this a trophic cascade). The possibilities are endless (and almost completely unpredictable) and the direct effect of this ecological change on humans is unknown, but should concern environmentally-conscious people nonetheless.

If an ecological catastrophe doesn’t concern you, it is almost assured that some economic impacts will result from the population decline of bats and the subsequent increase in insects. If an agricultural pest increases, there are the obvious costs associated with decreased crop production. The affected area is relatively minor in terms of agriculture, but if this spreads to the Midwest in the future, the economic costs may skyrocket. If forest pests increase, there will be costs (and they can be substantial) related to controlling the pest, whether through application of pesticides or more extreme measures. If an insect species that is a vector for a human disease increases, there will be medical costs.

As I mentioned before, we really don’t know what the ecological and economic outcome of WNS and the decline in bat numbers will be. As Scott Darling of the Vermont Fish and Wildlife Department said, “We may be living in an ecological experiment that will demonstrate the role of bats”

In January 2007, Al Hicks of the New York Department of Environmental Conservation discovered an unusual fungus growing on bats hibernating in four caves near Albany, New York. It quickly became apparent that the fungus was associated with very high mortality—probably higher than 90%—in all of the affected caves. Al dubbed the infliction White Nose Syndrome (WNS) because the most obvious symptom was the white fungus growing on the furless areas of the face. We have since learned that the white nose is not a universal symptom, and in some individuals the fungus grows on wing and tail membranes as well as under the skin. Other individuals show no external signs of the fungus at all. Further, other symptoms have since emerged that may be more universal indicators than the fungus—it appears that affected individuals are extremely underweight, and many are exhibiting unusual behaviors such as flying around outside of the cave during the day (I’ll discuss the symptoms and the research being done on the causes more in future entries).

It is unknown exactly how many bats died during 2007, but estimates of about 10,000 individuals seem reasonable. Unfortunately, in January 2008 we realized the problem had become much worse when it was discovered that WNS had spread to several more caves in New York. State agencies in the region set about the task of surveying most of the known bat hibernacula in the region. As I’m writing this, bats with visible white fungus have been discovered in about 16 caves (this number is growing) in New York, Vermont, and Massachusetts. It has been estimated from censuses done in previous years that as many as 500,000 bats may hibernate in the affected caves, although surveys are not being conducted this year so it is unknown what proportion of these individuals are affected. The fear is that the very high mortality seen in 2007 will continue in 2008 and many hundreds of thousands of bats may die.

A mysterious ailment, dubbed White Nose Syndrome (WNS), has been killing large numbers of hibernating bats in the Northeastern United States. There has been considerable media coverage describing the problem in recent months, but the ever-changing status of the problem and the solutions proposed by the research and management communities mean the coverage is often superficial. My goal in this blog is to provide a more thorough treatment of what we know about WNS and what is being done to identify and resolve the problem. My first several entries will describe the history of WNS, the implications of the problem, and the research that is being conducted on WNS. After the initial background information, most of my entries will act as updates as new developments unfold.