As the sun sets on the New Mexico desert, what appears to be a desolate landscape comes alive. A flash of movement from a cave and then, suddenly, thousands upon thousands of Mexican free-tailed bats flood into the fading daylight. But they are not alone. Swainson’s Hawks soar near the cave awaiting their prey. As the bats emerge, the hawks plunge into the swarm talons-first.
For those who have been keeping up with National Geographic’s Hostile Planet since the TV series premiered on April 1, such scenes of intense survival are not unfamiliar. As its name implies, the series explores how animals survive in some of the world’s harshest habitats, and the ways in which climate change is making their lives tougher still. In each episode—four out of six have aired so far—demanding environments challenge animals time and again. Baby Barnacle Geese jump from cliffs hundreds of feet high. Golden Eagles fight for a bite of a fox carcass. Pounding surf batters Rockhopper Penguins. It's survival of the fittest on the small screen.
The newest episode of the series, "Deserts,” premieres tonight and includes the showdown between the hawks and bats. Swainson’s Hawks typically eat small mammals, reptiles, and insects, but these hawks have learned the skills needed to catch and eat the swarming bats, says Geoff LeBaron, director of Audubon’s Christmas Bird Count. “For the Swainson's Hawks that would be nesting in the area where these bats are emerging, they know this is something that's a food source for them that happens nightly,” LeBaron says. “But it's a pretty specialized thing, because there really aren't many of these bat caves.” Swainson’s Hawk isn’t the only raptor species able to snatch bats out of the air; LeBaron says he has seen Prairie Falcons and Red-tailed Hawks engage in similar displays.
LeBaron, who has witnessed the spectacle of bats flying out of their cave firsthand in south Texas, says that it’s a matter of safety in numbers. With such a huge concentration of bats emerging from the cave at the same time, it’s difficult for the hawks to focus on any single one, he says. Instead of diving into the fluttering stream, the hawks wait near the edges to spot unlucky stragglers.
The confrontation between the bats and hawks was chosen for the show because it’s a classic example of desert survival, says Renée Godfrey, director of the bats shoot and producer for the episodes on oceans and grasslands. Life is not easy for the bats, which must leave the safety of their cave during daylight hours and travel perhaps 50 miles each direction to feed on flying insects numerous enough to sustain the colony. “It's a mesmerizing sight, thousands upon thousands of bats taking to the sky,” Godfrey says. “And then seeing the hawks coming in and predating on them, racing through the sky towards the bats and just picking on their prey, it was extraordinary.”
Over the month Godfrey and her team spent filming, she says they saw between 8 and 15 hawks at a time preying on the bats. The birds waited by the cave every day, knowing they’d be guaranteed a meal. While the scene is visually spectacular, Godfrey says it’s important to keep in mind that climate change is rapidly altering the desert Southwest and other ecosystems. More changes are on the way. The Swainson's Hawk, for instance, is climate-endangered, according to Audubon's modeling, and likely to lose more than three-quarters of its summer range by 2080. “The environments in which a lot of wildlife live are changing and becoming, in many cases, more hostile,” Godfrey says. With so many species already going to extremes just to survive, Hostile Planet proves to be more than mere entertainment—it's a call to action.
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Watch Hostile Planet: Deserts tonight at 9 p.m. ET (check local listings) on National Geographic and tune in on May 6 for the season finale, “Polar.”