The Congress Avenue Bridge is home to North America’s largest urban bat colony. Throughout the spring and summer, locals and tourists gather to watch as the bats emerge from below the bridge and blanket the sky as they begin their nightly hunt for food.

Bats have always called Austin home. In 1980, after reconstruction of the Congress Avenue Bridge, the Mexican free-tail bats found the vertical crevices below the bridge to be a perfect nesting spot. There are 15 of these crevices, which provide 14,000 linear feet of potential bat habitat. At the peak of the season, an estimated 1.5 million bats reside under the bridge.

The Mexican free-tail bats live in Austin during the spring and summer. At full size, they are about 2-5 inches long and only weigh about 1 oz, but they have a wingspan of 10 inches. Female bats give birth to a single pup each year in June. By August, the pups join the adult bats in their nightly flights for food. It is estimated that the bats travel up to 20 miles and consume between 10,000 and 30,000 pounds of insects each night!

When to view the bats:

The Mexican free-tail bats live in Austin from mid-March through November. Summer is the peak season for viewing bats, especially in August when the pups join the flight.

The bats emerge just before dark. During the summer, it is best to plan to be at the bridge by 8:00. The Bat Hotline (512.416.5700, x3636) can provide more specific estimates of bat flight times.

Where to view the bats:

Map and directions: Congress Avenue Bridge

• Stand on Congress Avenue Bridge. The bats will fly out towards the east.
• The grassy knoll at the Austin American Statesman (305 S. Congress Avenue, Austin, Texas 78704)
• Several local companies also offer guided tours that include bird watching. Two to check out: SegCity and Capital Cruises.

Bat Fest!

Austinites are very proud of their bat population. Every August, thousands gather for Bat Fest!, a 2 day festival on Congress Bridge that features live music, arts and crafts, food, and bat education. In 2008, Bat Fest! had to move one block west to the South First Street bridge amid protest from the owner of YLR, a local furniture store located at the south end of the Congress bridge. Many of the 40,000 attendees enjoyed the festival from the First Street bridge, then walked to the Congress bridge to view the bats at dusk. YLR has since gone out of business, and the festival will go on as planned on the Congress bridge on August 22, 2009.