Media & Education
BATS Magazine

Volume 14, Issue 4, Winter 1996

Time Out in Texas

A British bat worker lends her talents to BCI and the bats of Texas for an unusual sabbatical . . .

By Childs, Joan

A British bat worker lends her talents to BCI and the bats of Texas for an unusual sabbatical . . .

By Joan Childs

As I walked across the Congress Avenue bridge in Austin, Texas--the realization of an ambition for more than 10 years--I had to suppress the urge to shout out "I'm here, I'm actually here!" It takes seven years of work with Britain's Royal Society for the Protection of Birds (RSPB) before you're let out for good behavior on sabbatical, but I never had any doubt about where I wanted to spend my month of conservation work. When BCI said yes, I was over the moon.

I was assigned to the Bats and Bridges Project headed by Brian Keeley. He asked me to undertake a regular survey of the McNeil Bridge, used by 600,000 Mexican free-tailed bats (Tadarida brasiliensis). Until then, bats in bridges conjured up thoughts of stone arches over babbling streams. Well, I was in for a surprise. The McNeil Bridge resembles England's notorious Spaghetti Junction at rush-hour--roads and cars everywhere, plus a railroad thrown in for good measure. But as I peered into each expansion-joint crevice under the bridge, I could see hundreds of little faces peeking back out at me.

A number of experiments have been set up under the bridge to help determine the bats' preferences for temperature, crevice width, and surface texture. I noted the presence or absence of bats in each section of crevices (fortunately, I didn't have to count each bat individually), and then I checked to see if the bats were clustering more on a black surface rather than a white one, if they were roosting on plastic mesh or smooth concrete, and where they were positioned on artificial dividers. A removable partition was also inserted in one of the crevices, and this allowed us to view the bats to determine their sex ratio and general health. Brian called this the "batometer."

Until I went to Texas, the largest bat roost I'd ever seen was 500 bats under the eaves of a modern house in Bedfordshire, England. When 600,000 bats emerge, it's rather more of a spectacle! A few scouts flying in tight circles herald the main smoke-like ribbon of bats that lasts for 45 minutes.

While I was surveying the bridge one evening, I found a very weak female free-tailed bat on her back under the bridge. In the U.S., any mammal might have rabies, and it is recommended not to handle grounded bats. However, my rabies shots were up to date, so I gently picked her up and popped her into the bag I carry for such occasions.

Barbara French, a bat rehabilitator who works for BCI, soon had the little bat rehydrated. She thought the bat had used up too much energy migrating from Mexico back to the bridge. Barbara invited me over to her house "out in the boonies" to see her collection of waifs and strays: an eastern pipistrelle (Pipistrellus subflavus)--amazingly yellow compared to our pipistrelle in the U.K.--a big brown bat (Eptesicus fuscus), a red bat (Lasiurus borealis), and lots of Mexican free-tailed bats. Barbara put a cage of free-tails and a pot of mealworms in front of me, and I got to work feeding the hungry little group. I discovered that bat rehabilitation work in the States really isn't so different from that back home. Our species may not be the same, but the basics of bat first aid are identical; I felt quite at home. One of the bats I fed was "my" female. She was very hungry--hardly surprising once we had discovered she was eating for two. Barbara planned to release her the following weekend.

No trip to Texas would be complete without a visit to the spectacular bat colonies that inhabit some of the state's caves and tunnels. Doppler radar shows that when Central Texas's millions of bats emerge for the evening, they disperse to cover a massive area [BATS, Fall 1996]. We began at Eckert James River Cave, which hosts six million free-tailed bats and a few cave bats (Myotis velifer). Here I experienced, in true David Attenborough style, the huge guano piles heaving with insects. At dusk the emerging ribbon of bats is not only an experience for the eyes, but also for the ears and the nose! The flapping of twelve million wings sounds just like standing underneath electricity pylons on a foggy day, and the ammonia smell makes you catch your breath.

The jewel in the Texas crown is undoubtedly Bracken Cave. The sight of twenty million emerging free-tailed bats is a never-to-be-forgotten experience. For up to three hours before sundown, the giant columns of bats are visible for miles around. I saw a few bats with white fur and dark membranes, and one completely white albino. In the swirling mass of emerging bats, the albino showed up like a bright beacon. Red-tailed hawks swooped to catch unwary individuals.

I also spent one day out in the field with Jim Kennedy, who runs the North American Bat House Research Project. U.S. bat houses are very different from the bat boxes I'm used to. In England, our bat boxes are much smaller, with just one compartment, and typically not painted. I'm now setting up a project on a local nature reserve in England to compare the success of European bat boxes and U.S. bat houses side by side.

On our travels to inspect and advise on bat houses, we checked one of the famous Campbell Bat Towers. This historical tower was built in the early 1900s, designed to attract bats to control malaria-carrying mosquitoes. Guano was also collected and sold as fertilizer. I removed the latest guano accumulation and, with the aid of a ladder, climbed inside to check on the bats and view its internal structure.

I couldn't have wished for a better--or battier--trip to Texas, or for nicer people to live and work with. I'm now looking forward to sharing everything that I've learned and putting it to practical use. I would like to thank the RSPB for their assistance with this sabbatical project, and all the staff at BCI who helped me feel so welcome and shared so much with me.

Joan Childs works as an Investigations Officer with the Royal Society for the Protection of Birds in Bedfordshire, England. She also is an active bat worker and runs the Bedfordshire Bat Group.

The BCI staff adds: Thanks again, Joan, for choosing BCI. You were a joy to work with, and your contribution was immeasurable.

The author explores one of the historic Campbell Bat Towers.

The author counts the bats that have taken up residence in BCI's "bat abode," a type of bat house custom-designed to create roosting crevices under bridges.

All articles in this issue:

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