They say never to invite a vampire over your threshold, but warmer temperatures may usher some bloodsucking creatures across our southern border, invitation or no.
The common vampire bat currently dwells in southern Mexico and up the country’s coastlines. Studies suggest you won’t find this bat anywhere the thermostat dips below 50 degrees Fahrenheit, but as North America warms, the bat’s range is expected to increase by at least a third, pushing north into parts of Texas and possibly other southern states, including Arizona and Louisiana.
“Vampire bats are a very opportunistic species,” says biologist Shahroukh Mistry. “It wouldn’t take much if the temperature limitation was removed.” Still, the shift would likely take place over decades, and other factors, like disease, might inhibit expansion.
Government agencies and biologists are interested in tracking vampire bats partly because they transmit rabies. Using their razor-sharp incisors to puncture the skin, a bat can lap up more than half its body weight in blood in a half hour.
Vampire bats prefer livestock but have been known to dine on other mammals, even humans. (People may benefit from the bat’s bite: Desmoteplase, an anticoagulating drug made from its saliva, is in clinical trials for stroke treatment.) While the risk of rabies—which the bats can get, too—is a serious concern, Mistry points out that livestock can be vaccinated. Noting indiscriminate killings in Mexico, he says, “The worst thing that could happen is a knee-jerk reaction that harms vampire bats when they move into a new area.”
See a photo gallery of more species affected by climate change, from the adorable American pika to the mysterious narwhal.