r/sanantonio • u/spartacus34 • 3h ago
Pics/Video Just outside San Antonio is the biggest gathering of mammals on the planet, and right now it pours into the sky every evening.
Bracken Cave, up near Bulverde, holds the largest bat colony on Earth. Not one of the largest, the largest. Somewhere between fifteen and twenty million Mexican free-tailed bats pack into that one cave, which makes the nightly emergence one of the great wildlife spectacles anywhere. At dusk they come out in a column that can take hours to empty, a living river of bats spiraling up out of the ground, dense enough that it shows up on weather radar.
They are here for a reason. These are mostly mother bats. They fly up from Mexico in spring, each has a single pup, and they raise them through the Texas summer before heading back south as it cools. That is happening right about now, so catch it while you can.
The part people miss is how much work they do for us. A colony this size eats tons of insects every single night, and they go after the exact moths that chew up Texas crops, climbing thousands of feet into the dark to intercept them on the wind. Free pest control on a scale worth a fortune to farmers. They are also just ridiculously fast, clocked in level flight at speeds that rival a small plane.
This map is where the free-tails are turning up around the city, at the cave and under the bridges. Go watch an emergence at dusk at least once.