Prepare the Bat-Signal: Subdivision Plan Encroaches on Globally Significant Preserve
Published: May 22, 2013
Each summer our local weathermen look at the Doppler and tell us to disregard a cloud hanging over the Hill County. No, it’s not sign of some impending rainstorm, but the nightly exodus of at least 10 million bats from their summer home.
Bracken Cave in southern Comal County is widely regarded as the largest bat colony in the world, the summer nesting and breeding grounds for the Mexican free-tailed bat. Each night, a thick column of bats swarms out of the cave to feed before retuning at dawn.
“This is a globally significant site,” said Shanna Weisfeld with the nonprofit Bat Conservation International, which owns the nearly 700-acre nature preserve surrounding Bracken Cave. “We should be careful not to do anything that disturbs it.”
Like, say, create a 3,800-home subdivision bordering the preserve, situated right in the bats’ nightly flight path.
“This is a unique situation, so we have nothing to compare it to,” Weisfeld said. “We simply do not know what could happen to this treasure.”
Galo Properties, the site's developer, did not return several calls for comment.
For thousands of years, BCI estimates, young bats have been born and raised in Bracken Cave, learning to fly and forage in the surrounding area. Each night, those bats eat their bodyweight in insects, some of which are agricultural pests like the corn earworm and the cotton bollworm. A 2006 study of the eight-county region surrounding the cave estimates the bats are worth an annual $741,000 in pest control. In its recently updated Texas Conservation Action Plan, Texas Parks and Wildlife designated the bat a “species of greatest conservation need.”
Building homes, streetlights, schools, and pools next door could forever alter the bats’ flight pattern, BCI worries, contending those bats may instead roost in and around nearby homes instead of the cave.
And building a subdivision in the bats’ flight path threatens to expose residents to rabies, BCI claims; while instances are still rare, bats are the primary source of human rabies infection in North America.
The proposed site also sits atop the Edwards Aquifer’s environmentally sensitive recharge zone, where our main source of drinking water gets replenished with each rainfall. Under a city aquifer protection plan passed in 1995, developments over the recharge zone can only have 15 percent of its land covered by buildings and paved roadway (so-called “impervious cover”).
“We were surprised to see they’re planning such a high-density development because of where they are in San Antonio’s [extraterritorial jurisdiction],” said Annalisa Peace with the Greater Edwards Aquifer Alliance. While some developers have managed to sneak dense developments through by exploiting a loophole that allowed certain development plans to be grandfathered without the restrictions, it doesn’t appear Galo has taken that route, Peace said. She doubts, given the density of the proposed subdivision (at least 3,800 homes on roughly 1,500 acres), Galo could build within that 15 percent impervious cover cap.
> Email Michael Barajas