In the winter of 2006 scientists discovered a disease that was killing bats in a cave in upstate New York. Today (2015) White Nose Syndrome has killed more than 5.7 million bats in Canada and the continental United States. In Tennessee, nearly half of the counties with caves have confirmed infections. While the disease is devastating, especially with some of the more common species like little brown and tri-colored bats, the news is not all bad. While some caves have high mortality rates, others do not. And some of the endangered bat species appear to be less susceptible to the disease. Wild Side Guide Ken Tucker takes us underground to shed some light on a disease scientists are still trying to understand.
White-nose Syndrome (WNS) is a fungal disease that has killed millions of bats in North America. The disease is caused by a fungus from Eurasia, which was accidentally transported here by humans. The fungus, Pseudogymnoascus destructans (formerly known as Geomyces destructans), grows on the noses, wings and ears of bats during winter hibernation, giving them a white, fuzzy appearance. The fungus invades the deep skin tissues and causes extensive damage. Affected bats arouse more often during hibernation which causes them to burn up their crucial fat reserves needed to sustain them through hibernation, leading to starvation and death.
To date, seven cave hibernating species of bats in eastern North America are afflicted by WNS. These include:
Little brown bat (Myotis lucifugus)
Northern long-eared bat (M. septentrionalis)
Eastern small-footed bat (M. leibii)
Indiana bat (M. sodalis; federally endangered)
Gray bat (M. grisescens)
Tricolored bat (Perimyotis subflavus)
Big brown bat (Eptesicus fuscus)
Gray bats, one of Tennessee’s endangered species, appear to be less vulnerable to white nose syndrome, partly because they are naturally more active during hibernation and because they are larger and have more fat reserves. There are also positive signs in some northern state, where bats are returning to caves where populations had been destroyed and others are going into hibernation with more fat reserves than usual.
The Tennessee Chapter of The Nature Conservancy and Bat Conservation International are working in partnership to fund research aimed at stopping this deadly disease. So far, there have been some promising steps taken in the development of biological controls, things that will be safe for a cave environment while stopping or limiting the growth of the fungus. An artificial cave designed as a bat hibernation site that was built by the Nature Conservancy in 2012 could play a role in helping test biological controls. You can learn more about how it was constructed by watching this Wild Side story, Building the Bat Cave.
While some Tennessee caves are now opened with limited access, biologists with TDEC, TWRA, and The Nature Conservancy urge anyone entering caves to follow U.S. Fish & Wildlife Service decontamination protocols. You can download a copy of the protocols here. It is especially important that cavers be sure not to take gear that has been in caves infected with White Nose to other caves outside that area.
From show 2908
