The nighttime exodus of millions of bats ranks as one of Texas finest natural wonders. In season, Old Tunnel State Park, located in the heart of Texas Hill Country, provides prime bat viewing. If you plan a summer visit to Fredericksburg, Texas, be sure to reserve an evening for the bats.
Mexican Free-tailed Bats
Unlike their northern cousins, Mexican free-tailed bats do not hibernate in winter. Instead, these flying mammals spend time between Mexico in colder months and south Texas in warmer months. The bats arrive in Texas Hill Country around March and return to their winter homes in Mexico around October. Up to three million Mexican free-tailed and 3,000 cave myotis bats have repurposed the abandoned railway tunnel at Old Tunnel into their summer home.
The little Mexican free-tailed bat is less than five inches long and weighs about 14 grams (that’s just half an ounce), and are a tasty bite for hawks and owls. The bats emerge en masse to increase their odds of escaping predators flying outside the tunnel opening. The counter-clockwise emergence vortex serves the additional function of helping the bats to gain lift as bat bones are denser than those of birds.
Aerial River
At dusk, onlookers see a streaming black river flowing above the tree canopy as the little critters make their way south towards the Guadalupe River. The bats will swoop down to the river for a quick, in-flight drink of water and then fly to feeding grounds in farm fields as far as 100 miles away. The bats are insectivores, eating whatever nighttime insects they find. Their primary food are moths, and a Mexican free-tailed bat can consume as many as 40 in a night. Once full, the tiny creatures return to the tunnel to rest until the next evening feeding flight. Viewing a bat emergence is a must on any nature lover’s bucket list. My husband and I were transfixed in awe as the river of bats continued for almost fifteen minutes, and intrigued by the scent left in the bats’ wake. Yes, you can smell the bats! It’s a little like an umami scent.
Bat viewing tips
Old Tunnel has two viewing areas. Aligned with the tunnel entrance, the lower level is space limited and no children under four are allowed. The upper viewing area is also a wonderful option. Both areas require an advance reservation that can be made online at the Texas Parks and Wildlife website. Bats emerge most but not all nights. The mammals are fair-weather feeders and often stay put in the cave during rainy evenings. That makes sense as fewer insects are available during inclement nights. Docents were on site the night we visited. These volunteers are a wealth of information and source of great bat trivia.
Old Tunnel State Park
At a mere 16-acres, Old Tunnel is the smallest Texas State Park. The 920-foot tunnel, now home to our bats, was built at the beginning of the twentieth century to link Fredericksburg to Comfort by rail. The railroad venture didn’t pan out and the line was abandoned in the forties. In an effort to protect the bat colony, Texas Parks and Wildlife Department purchased the land in 1991 with the express purpose of protecting the bat colony. The area became a state park in 2012. The park has a mile-long trail that follows the old railroad bed. No camping is allowed at the park.
Alamo Springs Café
Why not have dinner before seeing the bats? Alamo Springs Café, adjacent to the park, claims to offer the best burger in Texas. It’s a funky café that looks like a house with a few too many additions on it. We ate there on a Saturday night and were treated to tunes from a local band. The café and patios are packed at dinner time, so be patient. The service is friendly and efficient. The burgers are great, but my favorite were the onion rings….awesome!
When You Go
Old Tunnel State Park is at 10619 Old San Antonio Road, Fredericksburg. Bat viewing for both the upper and lower areas requires an advance reservation. Bats don’t use alarm clocks, so you need to check the Old Tunnel hotline at (866) 978-2287 or check the park’s Facebook page to get the latest emergence time. Alamo Springs Café is at 107 Alamo Road. The café is open 11 a.m. to 9 p.m., Thursday through Sunday. There are also a few outdoor tables at Old Tunnel if you want to bring your own picnic.
Be careful driving home. The area is chocked full of deer, we almost hit a buck making our way back to Fredericksburg.
Tip
Frankie the Free-tailed Bat is a cute book for kids. It’s loaded with information about the bats. You can download a free copy courtesy of Texas Parks and Wildlife.