White-nose syndrome: it’s a silent invasion that causes greater destruction than a forest fire, but most people have probably never heard of it.
White Nose Syndrome (WNS) was first observed in bats in a cave near Albany, New York, in February 2006. The bats were uncharacteristically active during their hibernation time and had a frosty white fungus on their body, particularly in the area around their nose.
The condition soon spread to nearby caves, and overnight WNS became the Black Plague of the Eastern bat population. To date, experts estimate that nearly half-a-million bats have died, including 25,000 of the endangered Indiana bat. As of March 2009 there are 60 caves and mines with confirmed WNS outbreaks, spread across nine states.
Three years later, the cause of WNS is still shrouded in mystery. Suspected causes include climate change and use of pesticides that kill the insects on which bats feed. The fungus present in WNS bats thrives in humid and cool conditions, but wildlife experts aren’t sure if the white fungus is the cause of the bat’s maladies or just a symptom. WNS-afflicted bats seem to lack the fat reserves required for hibernation. Hunger or the effects of the fungus cause them to rouse from their hibernation early in search of food. The awakened bats soon die, at least partially from the effects of starvation and the cold. In some of the affected hibernation caves, mortality rates have been over 90 percent.
White-nose syndrome reached the Southeast last year. In the past months, bats with WNS have been identified in caves in West Virginia and in Virginia near the Tennessee border.
Experts have compared WNS to “colony collapse disorder” among honeybees, both for its devastation and its possible ecological implications. Bats are voracious predators of insects and can eat up to half their body weight in insects in one night. Their decline disturbs a delicate balance in the ecosystem. Increased insect populations threaten crops and native plants and can lead to an increase in insect borne diseases.
Experts aren’t sure how WNS is transmitted. They believe it is spread primarily bat-to-bat, but they have also noticed that it tends to occur in caves frequented by humans. Subsequently, they have asked cavers to stay out of caves and mines until the problem is understood. Caves on many federal and state-owned lands have been closed, including those on public lands in Virginia and the caves in the Great Smoky Mountains National Park Violators of these closures will face hefty fines.
Private owners have been asked to voluntary close their caves in areas where WNS has been found. Speleological organizations have been the greatest supporters of these cave closures, preferring to sideline their hobby rather than risk damaging the most visible life form of the underground world. •
