Holy Mansion, Robin! Texas Has Better Bat Cave

Out past the cattle pens and dripping springs on his ranch, J. David Bamberger is spending $200,000 of his own money to build the perfect home for his neighbors. It has some unusual features - such as large concrete- domed ceilings to hang from and nearby lakes full of juicy insects. For the Mexican free-tailed bat, it's going to be hard to resist.

Next March, Mr. Bamberger hopes more than a million bats will call this place home. After all, this is the largest man-made bat cave, or "chiroptorium," in the world. And it's all a part of Bamberger's campaign to restore habitat for the little bug-eating mammals, whose caves are rapidly disappearing in the pell-mell construction boom in the hill country of central Texas.

"There's been a major rush to develop land in the hill country, so we're losing caves right and left," says the lean, silver-haired rancher, driving his dusty pickup along the gravel road of his ranch. "People say I'm goofy about bats, but they play such an important role in our ecology, keeping the insect population under control. I just knew I could do something to help keep them around."

It's an attitude that Bamberger learned at home from his mother, an Ohio farmer and self-taught naturalist. In adulthood, when Bamberger made his fortune running a chain of fried-chicken restaurants, he decided that it was time to put his environmental ideals into practice, using "my back, my mind, and my checkbook."

Dedicated to wildlife

For conservationists and the scientists who study bats, the arrival of Bamberger, a wealthy rancher, has been a welcome surprise.

"J. David Bamberger is special, he's dedicated his life to conservation," says Bob Benson, spokesman for Bat Conservation International, based in Austin. "Bats are just one component of his effort to preserve the land and preserve the native habitat. It's pretty impressive."

Indeed, Bamberger's ranch itself is a living example of good environmental management. When he bought the property in 1969, there wasn't a drop of water on the land. But when Bamberger reintroduced native grasses to the ranch, rainfall stopped washing off into gullies and began seeping down into long-dead springs. Now, the ranch has several clear-water ponds big enough to water-ski on.

The chiroptorium (a word that Bamberger coined to describe a man-made bat cave with a separate observation room) has been built to impress. The 15-foot entryway, which faces north, leads in a spiral passage to three domed rooms. Visiting scientists will have windows and infrared lights to help them watch the bats as they breed, raise their pups, and jostle for a place to rest after their typically long nights of feeding.

Engineer Jim Smith spent months consulting with bat scientists before beginning construction this past March. Bats don't fly in straight lines, so he designed the structure with curved walls. Bats like warmth, so he built the domes on a slope so that the cold air would flow out the entrance and the collected bat body-heat would keep the cave at a toasty 110 degrees and more.

Good for bats

"If you were a bat, it would be a fun place to fly around," says Mr. Smith, pausing before installing a solar panel to power the cave's infrared lights. "If I were bat, I would consider staying."

For his part, Bamberger says man-made batcaves are just one example of the way farmers and ranchers can combine environmental methods with a profit motive. In Austin, for example, tourists come from miles around to see the millions of free-tailed bats that call the Congress Avenue bridge home.

Besides tourist income, a chiroptorium has other benefits. Farmers could generate up to $10,000 in revenue a year by selling the guano as fertilizer. "What other crop can you plant that you don't have to touch ever again, and it generates $10,000 a year?" he exults.

But even Bamberger notes that just because he built a cave, there's no guarantee the bats, now wintering in Mexico, will come, or stay. "It's up to them," he chuckles.