Nature

Cavern

View up to entrance to Devils Sinkhole from inside the cavernLife thrives in the cavern, even though it’s underground with limited to no sunlight.

The most obvious life form found in the Sinkhole is the large seasonal population of Mexican free-tailed bats. Up to 3 million of these small, flying mammals pour out of the cave to forage for insects on summer evenings. Three to four thousand cave swallows live in the cave at night while the bats are gone.

Portions of the cave are below the water table. Because of this, several freshwater lakes lie around the cave’s perimeter. These lakes support two unique crustaceans: a native amphipod and a rare aquatic isopod.

A type of Mexican fern grows on the walls of the vertical shaft of the cave. These ferns only grow in a few locations in the United States.

Above ground

View of entrance of sinkhole from above with bats exiting.The 1,860 acres of the natural area are typical of the Edwards Plateau.

Deeply cut canyons are on the southern end of the site. These canyons support trees such as escarpment black cherry, Buckley oak, Lacey oak and pinyon pine. Plateau live oak dominates the uplands.

Small bird perched on a twig.
Black-capped vireo

Growing populations of breeding black-capped vireos and endangered Tobusch fishhook cactus now occur here.

Learn more about birds of this area by downloading Birds of the Edwards Plateau | PDF.