The Tennessee chapter has made the preservation of cave ecosystems one of its highest priorities--and for good reason--Tennessee has more caves than any other state, with more than 10,000. In fact, 20% of the known caves in the U.S. are in Tennessee! The Nature Conservancy directs the leading cave protection program in Tennessee.
Creatures in the Dark
Nearly 1,000 species, mostly crustaceans, insects and arachnids, live exclusively in caves within the lower 48 states. The Nature Conservancy considers 95 percent of all cave creatures in the United States to be vulnerable or imperiled. However, the federal government has not extended the protection of the Endangered Species Act to most of these cave creatures, even though they are highly vulnerable.
Subterranean systems are linked to the surface by sinkholes and other entrances. Cave-adapted species, such as cave crayfish, depend upon the surface for clean water and organic debris that serves as a food source for small invertebrates. Alterations to the landscape above a system, or within the water recharge area of a cave, can affect both the quality of water within the cave and the amount of food input to the system.
Bats are another important protection target for The Nature Conservancy. They are especially sensitive to disturbances in caves. Caves serve as hibernation hideaways for many kinds of bats, including gray bats and Indiana bats (both listed as endangered species and both found in Tennessee). They form large colonies numbering in the thousands and sometimes the tens of thousands.
Waking bats during hibernation causes them to use up energy that they have stored to survive the winter often leading to their death. During the summer, some bats will again form large colonies in caves. Disturbing summer maternity colonies can cause the death of flightless young bats when they are knocked from the walls to the floor by panicked mothers.
Fighting White-Nose Syndrome
Over the past decade, an epidemic called white-nose syndrome has devastated bat populations in the eastern United States and Canada. More than 6 million bats have died. Some species may go extinct.
The culprit is the invasive fungus Pseudogymnoascus destructans (Pd.), which is not native to North America. It infects cave-dwelling bats, damages their wings, causes them to wake more frequently and raises their metabolism during winter hibernation. As a result, bats exhaust critical stores of fat they need to get through the winter, which leads to starvation. Most caves where the fungus has appeared have seen bat die-offs of 90 percent or more.
We work with partners to monitor bat populations at caves across Tennessee, determining how white-nose syndrome is affecting bats across the state and sharing that information with scientists working on treatments to fight white-nose sydrome.
TNC and partners have funded scientific research projects designed to test methods of fighting and controlling white-nose syndrome. One extremely promising project, which employs bacteria used to keep bananas from ripening too fast, has been shown to stop the WNS fungus from growing. It led to the release of healed bats!
But because we don’t know what tools or techniques for fighting WNS will be most effective and cost efficient, it’s imperative that we try many approaches. Controlling this disease may require employing several different strategies.
Unique and Complex Systems
Protecting Tennessee’s cave creatures means protecting cave ecosystems, and that poses no small challenge to conservationists. The Nature Conservancy’s Tennessee Cave Program has been working for the last 30 years to protect these unique and complex systems. Collaborating with partners, the chapter completed a survey ranking the state’s top 100 biologically significant caves and developed protection strategies for endangered caves throughout the state.
Little is known about the animals living in this complex subterranean landscape. In 2001, the Conservancy began working with world-renowned zoologist Dr. Julian Lewis to launch the largest cave-survey project ever undertaken in Tennessee--to survey 100 caves on the Cumberland Plateau. The results have been astounding: the collection of 48 previously unknown species, as well as more than 150 insects considered globally rare.
The Conservancy will use this information to develop protection strategies for these delicate ecosystems. "Even in a field where I have become pretty accustomed to spectacular results, I find this to be stunning. Fieldwork in the Cumberlands is, to a cave biologist, like unwrapping presents on Christmas morning--everyday," said Lewis.
Our Partnership with the National Speleological Society
The Nature Conservancy works closely with local members of the National Speleological Society to achieve our cave conservation, research and management goals. This long-standing and valuable partnership was formalized in 1992 through a Memorandum of Understanding. Local cavers help TNC with stewardship activities such as fencing, cave gates, and sink hole clean-up.