The 1.5 million Mexican free-tail bats fly off on their nightly hunt for insects is one of the many free attractions that brings hundreds of visitors to Austin. Photo by Stephanie Bathurst.

J.P. Foley recently spent a Sunday evening standing under the Congress Avenue Bridge for the third time in four years, waiting for the city’s famous million-bat colony to take flight.

“I have some friends in from out of town,” said Foley, an Austin resident, “and I wanted to show them something different, unique to Austin.”

From March to November, hundreds of Austin residents and visitors line the sidewalks above and trails under the bridge at dusk to watch approximately 1.5 million Mexican free-tail bats fly off on their nightly hunt for insects. In all, about 100,000 people come to see the Mexican free-tail bats every year, according to Bat Conservation International, the not-for-profit research and advocacy group.

And while watching the bats can be as cheap as securing a good spot on the bridge, the flights also contribute a bit of financial lift. The BCI estimates that bat-watching adds about $10 million to Austin’s economy. Most of this money comes from bat-themed river cruises, kayak and Segway tours and restaurants offering a riverside view of the nightly flight. Their insect consumption also contributes to the prevention of $3.8 billion in damage to American agriculture, according to a study released in March.

Austin’s annual Batfest, held on Aug. 27 and now in its seventh year, also contributes to tourist activity by drawing people downtown for more than 50 food, art and specialty vendors. Organizers had expected 40,000 attendees this year before the record-high temperatures resulted in a light turnout. But the Sunday before Labor Day, an especially large group of people came to see the colony, according to a refreshments vendor, Lee Spalding. “The crowds definitely exceeded our expectations,” he said. “This was even bigger than the Fourth of July.”

Spalding says that he encounters travelers from afar all the time. “Tonight I’ve met people from England and India,” he said.

There are no numbers on how many people come primarily to see the bats, but the scene clearly seems to add to out-of-towners’ Austin experience. Paul Tanenbaum of Boston remarked on the uniqueness of the experience. “I’ve seen bats before at Carlsbad Canyon,” he said, “but never so many like this, and never in an urban area.”

Lorena Vustos of Albuquerque said that she loved the experience of seeing the colony take flight: “It engages all your senses—you can watch them, hear them waking up and rustling, even smell them.”

And the bat buzz can mean good business. Spalding reported, to his pleasant surprise, that he sold out of everything in his refreshment cart that particular Sunday. For those lounging on the banks of the lake, it was an easily accessible live show in Austin.

“It’s like an old church picnic,” Spalding said about the appeal of the bats. “It’s about the last thing out there you can do with your family for free. It’s entertainment without the flash, and a good excuse for people to get together and see something different.”