The Tennessee chapter has made the preservation of cave ecosystems one of its highest priorities – and for good reason – Tennessee has the highest number of known caves in the United States. 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. About 95 percent of the species are listed as vulnerable or imperiled by The Nature Conservancy. Although many of these species are known to exist in just 10 or fewer caves, few are listed under the Endangered Species Act. In Tennessee alone, our caves harbor hundreds of rare and unique species.
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. The Conservancy works with partners to monitor bat populations at caves across Tennessee.
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.
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.