Each night, thousands of bats emerge from a cave deep in the heart of Mexico’s Yucatán Peninsula to feed on flying insects in the surrounding forest. With so many individuals racing toward the cave mouth at once, there’s no shortage of hazards along the way—from the cave’s uneven walls and overhangs to other members of the colony. Indeed, as bioGraphic’s video “Lens of Time: Bat Ballet” illuminated, collisions during these nightly emergences are commonplace—albeit generally not harmful. But, as the hapless Mesoamerican mustached bat (Pteronotus parnellii mesoamericanus) in this photo might attest, something far more deadly often awaits.
Drawn to this place by the seemingly limitless source of mammalian meals, Mexican night snakes (Pseudelaphe flavirufa) climb the cave walls and dangle from crevices in the ceiling like beads strung at the entrance of a dim curio shop. There they hang, waiting for a bat to pass close enough for a lucky strike. It’s not known exactly what information the snakes rely on most to time and direct their lunges, but Rutgers University herpetologist Sara Ruane thinks this particular species likely uses both tongue flicks to taste the air for bats, and sight whenever there is enough light to see a bat fluttering by. Success, however, is by no means certain. In a bat cave in Jamaica, scientists watched as a snake—a species of boa that uses a similar hunting strategy—made 200 unsuccessful strikes over a period of an hour and forty minutes.
What may seem like an unusual, and haphazard, hunting strategy is actually common and widespread, occurring essentially wherever large colonies of cave-dwelling bats live—from Florida, Texas, and Colombia to Guam and Southeast Asia. Scientists have found that at least 20 different snake species enter caves to prey on bats. Clearly, even though the odds of catching a flying bat with any one strike might be low, a high number of bats can overcome even those bad odds.
Despite the pressures that snakes place on bat colonies, scientists aren’t too worried about the impact of these predators. According to Angelo Soto-Centeno, a bat biologist at the American Museum of Natural History, the colony here in the Yucatán is likely much too large for the snakes to have any significant impact—at least for now. While white-nose syndrome, a disease caused by a fungus (Pseudogymnoascus destructans) that infects hibernating bats, has devastated bat populations across North America, so far it has had little impact on bats that live in warmer climates. Habitat destruction, pesticide use, and the commercialization of caves currently pose much greater threats to this and other colonies—and to the critical roles that these animals serve as pollinators and consumers of agricultural pests and insects that spread human diseases.
Kantemo, Quintana Roo, Mexico
Fernando Constantino Martínez Belmar was born in Yucatán, México, and developed a fascination for nature at an early age. This enthusiasm led Belmar to study biology in college, and ultimately to pursue a career as a wildlife and conservation photographer. Through his work, he aims to show not only the beauty of nature, but also the issues that it faces and its relationship to humans. He uses his images to tell stories that inspire greater environmental awareness.