The Ecology of Virginia Caves

Caves are a unique habitat. There is no light, so expect to find animals but not plants in a cave. The food chain for animals that live exclusively in a cave is based on the little bit of detritus that washes in, or on the animals that feed outside the cave. Bats can create great mounds of guano underneath their roosting sites, and various forms of life from bacteria to cave crickets can live on the energy provided by that food source.
Most commercial cave tours involve walking along a paved trail, looking at formations illuminated with lights hidden behind rocks or rock-colored shades. If the lights are left on regularly, then algae spores can germinate and grow on the cave formations in the moist environment. The chlorophyll used by the algae to photosynthesize food adds an unnatural green color and texture to the cave formations.

Caves are usually very moist environments. Salamanders, fish, and insects are protected against predators in a cave, making them an attractive niche. Obligate cave dwellers are those animals that have evolved to the point where they are no longer able to survive outside the cave, often because they have become blind. (Why should the Lee County cave isopod waste energy growing and maintaining eyes, when a cave is always pitch black?)

Caves also provide a steady temperature, reflecting the average temperature of the area. Only near the entrance of a cave will the temperature change between day and night, and with the seasons. Virginia caves are about 54-56 degrees, every day, every hour. (The one commercial cave in North Carolina, Linville Caverns, is always 52 degrees - it's higher in the mountains, so its average temperature is cooler even though it's further south.)

Caves are not always a static environment; they can change dramatically at times. A summer thunderstorm can result in a rush of water into a cave, importing leaf debris, raising the temperature, and even drowning bats and breaking cave formations if the cave fllods completely. (WARNING: cavers can also be caught... and drowned. Beware of entering wild caves if rainstorms are likely in the area. While you're underground, you won't hear the thunder and know when to head back.)

The Threat of Pollution

"Out of sight, out of mind..."


Caves and Springs in Virginia
Virginia Geology
Virginia Places