December 2005, Volume 3, Issue 12

The Stars Come out at Night

Not too many years ago, the discovery that a colony of bats was living under a city bridge was cause for near-panic and demands for extermination. Now, however, the bats are a cause of celebration. Besides their prodigious appetite for pesky insects, bats have become a tourist attraction.
So Houston, Texas, is delighted to have 250,000 Mexican free-tailed bats roosting in the expansion joints of the underside of its Waugh Drive Bridge over Buffalo Bayou, reports the Houston Chronicle. Reporter Barbara Karkabi accompanied about 70 adults and children one recent evening to watch the bats soar out from under the bridge and streak out for their nightly bug hunt.
“It’s really cool,” says 8-year-old Hannah Miles. “It’s like they are flying at you in a 3-D movie. [Bats] are one of my favorite animals. I like the way they act and communicate together.”
“We all thought that you had to travel to Austin to see this, and it turns out we have the same kind of bats here. We don’t have as many but, oh, my goodness, it’s wonderful to watch,” Glenda Barrett told the newspaper. Barrett is director emeritus of the Park People, a nonprofit group that adocates for parks and green space.
Austin, a smaller city 160 miles north of Houston, is home to America’s largest urban colony – 1.5 million Mexican freetails that spend their summers under the Congress Avenue Bridge. An estimated 135,000 people visit the bridge during each summer to watch the bridge bats emerge from their roosts in the downtown bridge. A 1999 economic study found that bat-watchers directly and indirectly add about $8 million a year to Austin’s economy. The Houston bat colony was documented in 1999, and Bat Conservation International has advised Houston bat supporters on how to develop the attraction without disturbing the colony.
“I think what attracts people is the sheer volume of the bats and the choreographed symmetry of it all,” said Diane Schenke, Park People executive director.
The Waugh Bridge is smaller than the Congress Avenue bridge, so the bat colony is unlikely ever to grow to the size of Austin’s, but the Houston bats have their own claim to fame, the Chronicle said. “The Bayou City bats live here year-round,” the paper reports. “As far as I know,” Schenke said, “this is the only bridge in Texas that has such a large colony of Mexican free-tailed bats [that stay] all year. All the others migrate to Mexico in winter.”
In Austin, for example, the bats head south in October and November, ending the twilight emergences until the following spring.
Schenke said it’s unclear whether the whole colony stays under the bridge through the winter, or whether some migrate southward even as other bats move into the roost from elsewhere in the area.
The Chronicle notes that the bats come out each evening at about sunset, and volunteer naturalists are at the bridge to answer questions on the third Friday of each month.
The paper suggests it’s worth a visit. “We have the wild in the middle of the city,” exclaimed a bat-watcher. “Isn’t it wonderful?”

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