Bracken Cave Preserve is home to the world’s largest known maternity colony of bats—an estimated 15 to 20 million Mexican free-tailed bats (Tadarida brasiliensis). Pregnant female bats migrate from Central Mexico to Bracken Cave each March and April to give birth. The yearly migration creates the world’s largest bat colony and one of the largest concentrations of mammals on earth.

BCI's Bracken Cave Preserve, Jonathan Alonzo
Visitors to Bracken Cave Preserve witness one of the largest assemblies of mammals on earth. Photo by Jonathan Alonzo.
Viewing events are family-friendly. Bat Conservation International.

From May to September, visitors to Bracken Cave Preserve assemble on wooden benches near the cave entrance. Anticipation builds. At dusk, millions of bats begin flying from the mouth of the cave into the evening sky for their nightly meal. The experience is sensory. Visitors hear bats in flight grow dramatically louder, watch increasing numbers of bats rise from the cave, feel the rush of air generated by flight motions, and catch whiffs of pungent bat guano from below.

Bat Conservation International owns and manages the cave and the surrounding 1,500-acre preserve. Bracken Cave is vital to the science of understanding migratory bat species. It also offers the public paramount opportunities to witness the wonders of bats.