Begetting Bats

by Natasha Ball


A single bat represents one out of every four or five mammals on earth. The Mexican free-tailed bat is the speedster of the 1,000 species on earth, known to cut through the air at the same rate as the yellow lines of a freeway vanishing into a rearview mirror. But the size of their colonies, the largest of which can top the population of New York City twice over, form a huge target. When humans pave the way for things like farms, shopping malls, and cave tours, bat habitat is destroyed. And then there are the flying insects, laced with agricultural pesticides. A nursing, migratory Mexican free-tailed bat can eat its weight in them each night.

While bat tourism is changing some minds, not everyone is sending off for kits to build backyard bat houses. Daniel Duncan dealt the first blow to the relationship between human and bats with his Histoire De L’Animal in the 17th century deeming vampiric the animals that had been embroidered on silk in China, where the sounds for the words for “good fortune,” “blessings,” and “bat” are virtually the same. Bats were revered on this side of the planet, too, starring as heroes in stories told by the Aztec and the Cherokee. By the turn of the 20th century, though, we’d read Dracula and decided bats were the devil’s henchmen, driven from cracks in the earth to puncture the pallid necks of our guardians of virtue.

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This Land Radio explores the worlds of beekeeping, Russian steak, and bat caves.

We’d been bused to the viewing area from Alabaster Caverns in northwestern Oklahoma on a couple of school buses, our heads bobbing along the tops of the brown seats as we lurched through the haze caused by a nearby grass fire on Oklahoma 50. Here, just south of the city of Freedom, bat watching is a spectator sport. We’d all migrated there—the bats from central Mexico, the bat watchers from as far away as Florida. Some of us had heard from friends or family about the bat watch, about the chance to watch the unanimous exodus of a million and a half bats from their roosts.

It’s promise enough to draw some 365,000 visitors every summer to Carlsbad Caverns in New Mexico, home to one of the world’s largest bat caves. Austin artist Dale Whistler created a rotating 18-foot statue of a Mexican free-tailed bat for display at one end of Congress Avenue, a tribute to the colony there, North America’s largest of the urban variety. Hundreds of passes are sold each year to the bat watch at the Selman Wild- life Management Area, where we disembarked from our buses. Even Governor Brad Henry was intrigued. In 2006, he named the Mexican free-tailed bat the official flying mammal of Oklahoma. Since the first year for the Selman Bat Watch in Oklahoma in the nineties, more than 17,000 have made the trip for the show.

It was mid-July, and the temperature had topped 110 that day. The prairie seemed tense, pulled tight by loss of water. Birds of prey glided up and down in spirals alongside the road, like tornados made of hollow bones and wings, waiting for a meal to emerge from the baked, red dust below. We quenched our thirst with iced water from a tailgate cooler, which we dispensed into glow-in-the-dark cups. Tiny black bats had been printed on the sides.

The manila envelope had arrived in the mail from the Oklahoma Department of Wildlife Conservation headquarters in June, the image of a bat with wings outstretched stamped on the front, hovering over the words, “first class bat mail.” The headings on the advisories inside were printed in that font I’d seen on makeup packaging at the Halloween stores. “Confirmation,” one read. I felt like I’d just gotten my acceptance letter from a secret society.

The office where I checked in for the bat watch was stocked with bat t-shirts and winged children’s hats with googly eyes. We bat watchers waited in line at the front counter, pressed close in the small space suspended 80 feet over a cool pocket of the largest public gypsum cave in the U.S. We were told to report to the dry grass and grayed benches that form the amphitheatre outside, where the smiling Melynda Hickman, a wildlife diversity biologist with the state, reviewed the ground rules for the evening. Adults, you’re responsible for your children. There’s no smoking on the school buses or at the viewing site. Make sure your mouths are closed while you’re looking up, watching the bats. (“Think about it,” she said.) If you have a cell phone or other mobile device, put it on a silent mode: “Used to be,” she told us, “we didn’t have to worry about this because you couldn’t get a cell tower down here anyway. But that seems to be changing.”

Later, trying to sleep, I crawled out of my sleeping bag. Past midnight, the air still felt like it had rushed from an open oven. I’d ridden the brakes of my car down the hill from the park office after quitting the bus, flipping on the brights to alert anything that might have been lurking in the woods around where I’d set up my camp. From where I lay under some netting in the roof of my tent, the Milky Way looked like a road paved through the sky, a mix of dust and gravel, unobstructed by the lights of the nearest metro, which lay on the other side of 140 miles of dark.

Along the road leading back to the caverns office were bulldozers, crawling along the bottom of a shallow, football field-sized hole. It glowed white against the black of the sky. The light from the lamps of the machinery scattered in the floating dust, turning it into a ghostly fog that rose toward an orange sliver of a moon. Right off the surface like that is how most of the world’s gypsum is mined. It’s in our toothpaste, the drywall, tofu, Kit Kat chocolate bars. It’s the white powder that’s dusted onto individual pieces of chewing gum to keep them from sticking together. This gypsum, though, from what Hickman understood, was being mined for the oil and natural gas sites in western Oklahoma, which were connected by an invisible circuit that seemed to hum constantly with the traffic of flatbeds and white trucks, with the Chesapeake logo on the driver’s side door.

The bulldozers switched to reverse gear, and the rumble of exhaust and the cadence of the warning call flooded whatever sounds might have been playing underneath. The bleat came again and again, down from the RV camps and swing sets on the hill, spilling into the bowl between caves where I camped. When I noticed that the sound had dried up, I realized I’d slept.

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When it’s time, the mother-to-be Mexican free-tailed bat forms a hammock out of the skin that stretches between her legs and her tail, like a cupped palm, soft and strong. She hangs by her thumbs from the roof of the cave as she gives birth, kept warm by the heat of hundreds of thousands of bat bodies. Her pup, already a quarter of her size, emerges feet first, then climbs her to nurse with its wrinkled lips. She grooms her young, nosing her scent into its pink skin. The two are still connected by umbilical cord as the pup fills its bare belly with her milk. She can identify her pup from as many as 3,000 other newborn pups, which will be left in the same square meter as hers. At dusk the new mothers will leave them clinging to the ceiling of the cave. The mothers join their aunts and sisters and grandmothers for the evening hunt. There are 17 caves in the U.S. hot enough for this colony, a coven of migratory, pregnant bats. Five of them are in Oklahoma.

Waiting outside are hawks. Some of them are content swooping in on the vermin that the emerging bats manage to stir up. Others have a taste for nursing bats, plucked from the sky—sometimes right out of the cave. And then, of course, was us. Bat caves have been vandalized in ignorance. Barriers have been built into entrances to guard against trespassers, unwittingly affecting accessibility for the bats and the temperature inside the cave. Orphaned pups that aren’t adopted by mothers that have lost their young eventually lose their grip and fall to the floor of their caves, sometimes in clumps, since they cling as much to each other as the ceiling of the cave. A certain type of beetle patrols there, through the guano terra, and they can pick clean the feather-light bones in minutes.

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It begins late in the winter over central Mexico, where the moths of the corn earworm emerge from the stalks, gravid and bent on migration, climbing thousands of feet into the sky. The Mexican free-tailed bat flies up to meet them, trapping the moths in the folds of their wings before snapping their bodies with their smiling jaws. It’s said that the economic impact of these bats is practically immeasurable. A group of bats the size of the Freedom colony will consume up 10 tons of insects each night. The insect force that could cost Texas farmers millions in pesticides and lost crops are headed off by these animals, each of which measures less than a foot across.

The male and female bats are together at this point. It’s been a year since they saw each other last. At night, they press north, hunting as they travel. During the day, the males trill and chirp to the females, singing love songs that are mostly inaudible to the human ear. Sometimes, a male hovers over a cluster of females, selecting one seemingly at random from the bunch and, while hanging upside down, mates her without fanfare. But then there’s the other way, when a male cordons off a female as a dangerous lover would do, isolating her from her family and friends. Then, he seizes her, digging his thumbs into her fur and pinning her wings so she can’t move. For just a few minutes, he whispers into her ridged, wide-set ears.

Once pregnant, the females usually travel to the same cave in which they were born, consuming their weight in flying insects each night along the way, wings beating 12 times every second, since bats can’t glide. Mike Caywood, the 20-year park manager at Alabaster Caverns, can smell when they’ve arrived. “They have a somewhat unique odor,” he told us.

The audience was small at the state’s first bat watch, made up of naturalists and biologists eager to evaluate the area for tourism. The department is allocated nothing from the state budget. Instead, it cobbles together its operating budget from the money it charges for things like hunting and fishing licenses. The bat watch stirs up enough cash to pay for payroll and the cost of the buses, Hickman said. Ticket sales from the commercial caves like Alabaster Caverns—where the slick mud along the lighted paths is packed hard from foot traffic, and visitors are asked not to touch the soft, clammy walls, soft enough to chip with a human fingernail—goes to the state Tourism and Recreation Department. Weekend visitors to the caves and bat tourists can match the population number on the welcome sign outside Freedom, which hovers just under 300.

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First, you see them. Then comes the sound, like your pulse when your ears are under water, as a million and a half pairs of long, thin wings swim through the air, pushing the wind behind their long tails with a breaststroke, mixing it with the air we breathed. A few times a bat would drop from the formation and swoop toward us, then lift suddenly out of view, like an acrobat swinging into the rafters, back into the dark. We sat in lawn chairs in the mowed viewing area, snapping the shutters on our cameras, shushing each other. The angry sound of cicadas in the woods behind us ruined the recording I attempted of the deep, almost nauseating sound of the colony in flight. All I could hear on my half-hour of tape were the vibrations of the timpani hidden inside those hard shells, the drumming of another kind of wing.

After we’d arrived at the watch area, a volunteer passed around a sheet of brown foam that’d been cut, she told us, to the approximate shape and size of a Mexican free-tailed bat. On its back was a similar figure, cut from pink foam—it’s bald, she pointed out, just like the babies when they’re born. A range man named Jerry McLaughlin was our tour guide for the evening. He’d learned the hard way growing up amongst these gypsum caves, he told us, speaking with a feathery lisp, that the water that flows from them are so alkaline that it will neutralize a car battery. He led our group on a nature walk through what he called a patchwork of plant families, which he was disappointed he didn’t get to illustrate with a quilt made for the purpose, which he’d forgotten to bring along. We stared at the top of the cliff Jerry pointed out to us, waiting for a sign of the scout bat that would serve as a sort of dimming of the lights for the evening’s performance. Jerry whispered to us that if we listened close, we might hear the sound of the bats in flight. He’d never heard it himself. Hearing aids are good, he told us, smiling, but not that good.

Frantic, a flying beetle crashed into my ear. A river of Mexican free-tailed bats had begun to flow through the airspace above us, twisting serpentine against the graduated colors of the sunset, hungry and on the hunt. The bats were still up there after dark, invisible but electric in the air like radio waves. As the ribbon evaporated, we gathered our water cups and camera bags from the clearing where we’d landed at the end of the tour, a path worn through shoots of little bluestem and buffalo grass. McLaughlin was still whispering: “That might have been the best one we’ve ever seen,” he told us.

Originally published in This Land Vol. 3, Issue 21. Nov. 1, 2012.