How To Make A Cave

1 human decides to give back to nature some of what nosotros have taken away . . .

By Susan Yard. Sander

"Open up for firsthand occupancy. Enjoy country living in the heart of the cute Texas Hill Country; one-of-a-kind spacious housing; 6,500 square anxiety of roostable wall space. Will commutation lodging for guano."

The first criterion for real manor is location. For bats, Key Texas, with its carved-out canyons, seems to be an ideal location. This is especially true for Mexican free-tailed bats (Tadarida brasiliensis), which migrate here each spring to give birth and raise their young. But with loss of caves to urban development, there is much contest for remaining housing. Fortunately, at that place'southward someone who wants to assist–BCI trustee
J. David Bamberger, who this year has created lodging for time to come generations of Texas bats by building his own cave, literally from the ground up, on his 5,500-acre ranch in Johnson City.

The Bamberger ranch, known as "Selah" (a Biblical give-and-take meaning "to suspension and reflect"), is defended to conservation, instruction, and research. The approach is multifaceted, including rangeland restoration with native grasses and trees, as well as protection of nesting habitat for two federally listed endangered birds. For Bamberger, "enhancing" bat habitat was a natural extension of Selah'south conservation and stewardship mission.

He was introduced to bats more than a decade ago by Andy Sansom, an advisory BCI trustee and the Executive Director of the Texas Parks and Wildlife Department. Sansom took him to Bracken Cave–the summer mecca of more than twenty 1000000 Mexican complimentary-tailed bats–which BCI now owns and protects. Seldom at a loss for words, Bamberger was rendered speechless by the endless stream of emerging bats. Several years later, he became a BCI trustee and chairman of the Bracken Cave Commission.

Over the years, Bamberger has organized volunteers to brand Bracken Cave more attainable and attractive for visitors, and in 1995 he began hosting Members-Only Nights (see folio nineteen). Simply in that location was another idea in the back of his mind. About five years agone, he asked BCI founder Merlin Tuttle what he idea about constructing a man-fabricated cave equally a bat roost. Tuttle thought information technology just might be possible.

Although Bamberger fabricated his fortune as a founder of Church's Fried Chicken, he had a dream since his humbler beginnings of doing something important for the surroundings. He considers himself a land steward and his ranch an investment in Mother Nature; the bat cave, though a chance, would be one way of giving back some of the habitat that humans take destroyed.

Money is a handy tool to make things happen, simply Bamberger likewise does his homework–finding people who have the skills to transform his dreams into reality. For building his vision of "the world'south largest human being- made habitat for the free-will utilize of wild mammals," that person turned out to be Jim Smith from Santa Fe, who had trained in industrial design at the Rhode Island School of Pattern.

Knowing trivial virtually bats, Smith began with a crash course on their habitat needs. A master of particular, he visited several area bat caves and then sought out the experts–not only at BCI, but also at universities and agencies across the country. He had many burning questions: Do bats have a preference for the height of interior spaces? How much flight room do they need? What about the variety of crevices and holes in the walls? At what point should the walls brainstorm to bend in? How much daylight is tolerable? Should the shape of the entryway somehow adapt to emergence patterns?

"Having BCI nearby in Austin was great," Smith comments, "I was able to call upon the staff for their scientific expertise. They gave ongoing feedback every bit I fine-tuned my designs."

The first step was to choice a expert site at Selah. Bamberger wanted an easily accessible spot with the right infinite for a future viewing platform. Merlin Tuttle advised that information technology should have a clear flight path, nearby water, proficient drainage, and the right orientation to capture warm air.

A canyon was selected, and structure quickly followed. Leroy Petri, the ranch engineer, cleared the vegetation, sculpted the canyon to divert natural drainage, and installed drainage culverts. He then poured footings and a foundation for the 3,000-square-foot floor.

Smith's pattern for the cave began with the shape of a nautilus shell. Ii domes would provide open space in the interior, as well every bit spanning strength. Tuttle confirmed the size of the large dome and its slopes (twenty anxiety high, 40 anxiety in diameter), stressing the need for a liberal opening for emergences. In Smith's stance, at that place's no reason something functional or structural can't likewise be aesthetic. True to this goal, after Smith's coiffure had bent and tied 20 tons of re-bar, his cavern structure became a magnificent sculpture–truly a piece of work of art.

Meanwhile, he had been consulting on design ideas with Brian Keeley, who, equally BCI's Bats and Bridges Project Coordinator, specializes in artificial habitat. Keeley emphasized that the ceiling and walls would need texture; he then began thinking of ways to increase the available roosting space. In the finish, the pair decided to extend textured panels from the ceiling and add together an assortment of eye hooks for "curtains" that bats could roost on if needed.

In keeping with the ranch'southward education and research goals, Keeley, Smith, and Selah's instruction director, Margaret Campbell, realized that as long as they were building such an astonishing construction, it would be a waste not to incorporate an area for observation. Bamberger agreed. This idea of an adjoining observation room gained enthusiastic support at a June open house for members of the scientific community. Visitors included university researchers, such as noted free-tail expert and BCI scientific advisor Gary McCracken, also as wildlife biologists from the U.S. Fish and Wild animals Service, Texas Parks & Wildlife, and the San Antonio Zoo.

Balancing input from the scientists, Smith worked out more details of the room, such as the design of custom-made windows, which will allow researchers to monitor colony activities. The finished ascertainment room now looks like Control Central: There are port holes for positioning lights and cameras within the domes; monitors for temperature probes; mounts for future installation of infrared lights; and even a special drop-door for cleaning the cave side of the observation windows. Of class, everything is solar-powered.

The last stage of the cave construction was the application of 300 cubic yards of gunite–a blazon of physical used for swimming pools (jokingly referred to on this job equally "guanite"). It was peradventure the first time gunite was ever sprayed upwards rather than downwardly, and with a consistency like mashed potatoes, the messy material caused a fair amount of grief. With a picayune ingenuity and modification, however, it adhered to form an outer shell, 12 inches thick at the base, tapering to half-dozen at the top.

Except for minor details, the cavern was completed in October–seven months after Smith beginning arrived in Texas. The exterior will presently be waterproofed and covered with a layer of soil. Native vegetation volition be planted on top, and the entrance will exist mitt painted to wait more than natural, so that, in the future, the cave will blend into the landscape like any other Texas Hill Land cave.

But what practise you telephone call it? Bamberger is combining chiroptera (for bat) and auditorium (an area for assembling) to coin his new give-and-take, chiroptorium, defined as "a man-made cavern-like habitat for bats consisting of several big dome structures with connecting passages and a split observation room."

Even before the chiroptorium was completed, it had attracted more media attention than anyone expected. So far, stories near the unique venture accept been featured in national newspapers and in the New York Times Magazine, People, Texas Monthly, and Texas Parks and Wildlife Magazine, as well as on idiot box and radio interviews, including the "Voice of America" radio program broadcast effectually the world. Few reporters could resist calling the idea "batty," but well-nigh have likewise given information technology due respect every bit a positive attempt for the environment.

Now the just question remaining is: If you build it, will they come? Unfortunately, no one will know until next spring or across, when the bats return to Texas.

"Given the Central Texas location and the quality of the design," comments Keeley, "I won't be surprised if bats claim it as home next year."

Tuttle concurs, adding "Mexican gratis-tails have moved into every structure we have inadvertently made for them in this area over the past century."

Sometimes, notwithstanding, it takes years for bats to observe and move into bogus habitat. Bamberger is willing to wait, but he calmly adds that he does have a redundancy plan: "It'll certainly make one heck of a vino cellar."

[AUTHOR BIO]

BCI fellow member Susan G. Sander, founder and education director of the Riverside Nature Centre Association in Kerrville, Texas, writes on environmental and land-employ topics.

Cave designer Jim Smith, left, and owner J. David Bamberger, correct, inspect the completed interior of the primary dome.

The offset cave structure, made of re-bar with temporary supporting beams.

The view of the unabridged re-bar construction from backside.

Workers spray gunite onto the cave shell to form a last hard coating.

J. David Bamberger, left, and Jim Smith, right (both pictures), stand in the high-tech observation room, looking out onto the main chamber, where they hope to see bats roosting in the near future.

The October BCI board meeting concluded with a visit to the chiroptorium. The cavern will soon be covered with soil and vegetation to blend into its surround.