By the end of November, San Antonio, Texas's colony of free-tailed bats will have flown south to Mexico. That's when the city plans to seal off the roosts under the Houston Street Bridge, leaving the bats homeless when they return in the spring.

Unlike Austin, Texas, just up I-35, which encourages bats to roost under its Congress Avenue Bridge -- and which draws tens of thousands of visitors each year to watch their en masse departures at dusk -- San Antonio has never really embraced its bats. If it had, the city could have had its own tourist bonanza. Instead, it complains that bat guano and urine are polluting the San Antonio River, even though, opponents argue, the bats in Austin haven't polluted its Town Lake, and there are 1.5 million of them.

A more plausible explanation for San Antonio's antipathy is that its bat roost is in the heart of its successful "River Walk" downtown shopping and dining district. The city has expressed concern over the smell -- its Parks and Recreation Department deodorizes the bat bridge every morning -- and fears that its leathery guests may lessen the spending splurges of its most upscale consumers.

It is unfair to say that San Antonio is anti-bat. The city would probably be happy if the bats relocate next year to another San Antonio bridge, in a part of town with less expendable income. Note: The photo here is a charming section of the Riverwalk, but not of the bridge preferred by the bats.

[Update: The bridge roosts were sealed in early 2007, and the bats are gone.]

[10/29/2006]