One of the more unique advantages to living in Austin, Texas is the opportunity to see the largest urban bat colony in the US. While some people find them spooky and scary, others enjoy the natural wonder of watching more than a million Mexican Free-tailed Bats emerge from the Congress Avenue Bridge every night from late March to late October. There are a number of viewing spots available, and even in the wintertime a few strays can be found flying out over Town Lake from under the bridge. Whether living in the area, visiting on vacation or in the city looking for Austin real estate, the bats are a curious site that most residents would agree should be experienced at least once.

Purpose

Bats are nocturnal animals and wait until dusk or dark to leave their Austin home under the Congress Avenue Bridge to venture out for food. They eat mostly insects and help to keep the Austin mosquito population relatively low. The bats began congregating under the bridge after renovations were made to the structure, seeming to create an ideal environment for the mostly female colony.

Viewing

There are a number of ways to view the bats. Rent a kayak and paddle out in the water, or sit on the banks with a blanket and a picnic. Some stand on top of the bridge as they fly out, while others congregate on building balconies on the northeast side of the water. There are a number of restaurants that have prime viewing, and even a company that rents bicycles for people to ride down to the bridge.

Time

The bat flights commonly last about 20 minutes, but have been known to take up to an hour. The creatures resemble a plume of smoke as they fly out in a semi-orderly fashion and can be heard coming before they are seen. Depending on the viewing method, most places recommend visitors to arrive early. Boats and cruises require reservations. Restaurants that offer a prime view have limited outdoor seating.

Bat Facts

The Mexican Free-tailed Bat is about three to four inches tall and weighs about a half ounce. These creatures, dubbed the official "flying mammal" of Texas, live to be about 30 years old and usually have one pup each year. Bats are mammals and nurse their young. The babies are typically born in the summer months of June and July. Once the young bats are old enough to fly out on their own, they may join the nightly foraging party. The majority of bats are gray or brown in color and leave the bridge in late October through early November to migrate in Mexico for the winter.