More than 1,400 bat species live around the world, except in Antarctica and a few remote islands. What makes these flying mammals so successful?
Over their 50 million years of evolution, bats have developed ingenious solutions to life’s challenges, from a built-in sonar system for finding prey to dexterous wings that create the fastest horizontal flight of any animal on Earth.
“There is still a lot to learn, but it is clear that bats really do have superpowers,” says Rodrigo Medellín, an ecologist at the Institute of Ecology at the National Autonomous University of Mexico and a National Geographic Explorer.
“Bats are showing us how to live a better life,” for instance by serving as models for healthy living and longevity.
(On the latest episode of our podcast Overheard, we chat with Medellín—who for decades has worked to show the world how much we need bats, from the clothes we wear to a sip of tequila at the end of a long day. Listen now on Apple Podcasts.)
Superpower #1: Echolocation
Despite the popular myth, bats aren’t blind. But many of them do not rely on vision as their primary sense, instead use echolocation to navigate and find food in complete darkness. (Learn more misconceptions about bats.)
Echolocation is a way of perceiving one’s environment by bouncing high-frequency sounds off objects and listening for their echoes. From these echoes, bats can calculate the distance, size, and shape of objects, such as a tasty mosquito. This natural sonar is so sophisticated that some bats can detect an object as small as the width of a human hair or recognize differences in echo delays of less than a microsecond.
“Echolocation is a flexible and versatile way of understanding the world,” Medellín says.
Recent research also suggests that bats may be less reliant on echolocation than previously assumed.
National Geographic Explorer and University of Colorado biologist Aaron Corcoran found that bats fly for extended periods of time in silence, seemingly to avoid being eavesdropped on by other bats. When not echolocating, bats may turn to vision and spatial memory to find their way.
Superpower #2: Speedy flight
Bats are the only mammals that use their muscles to fly via so-called self-powered flight. This makes their flight techniques unique in the animal kingdom.
Bat wings resemble modified human hands, with elongated “fingers” connected by a flexible skin membrane. The flexible wings, packed with blood vessels, nerves, and tendons, are supported by special muscles that make bats efficient and agile fliers. Unlike bird or insect wings, bat wings can fold during flight in various ways, similar to the way that a human hand can close into different shapes.
It may surprise some people to learn that “the fastest self-powered flight on Earth is the humble Mexican free-tailed bat,” Medellín says. In 2016, researchers in southwestern Texas recorded Mexican free-tailed bats reaching speeds of up to a hundred miles per hour, easily making this 10-gram bat the fastest mammal on Earth.
“The peregrine falcon is cheating,” quips Medellín. “He uses gravity to accelerate.” (Read how Medellín became the “Bat Man” of Mexico.)
Superpower #3: Longevity
As a general rule in biology, smaller animals have shorter life spans than larger ones. But bats are rule breakers: They’re the longest-lived mammals relative to their body size. The oldest bat ever recorded was a tiny Brandt’s bat in Russia, which weighed less than a quarter of an ounce, yet lived at least 41 years.
Recently, scientists looked inside bats’ cells for the secrets to their exceptionally long lives. They focused on telomeres, protective structures found at the ends of chromosomes. In most animals, telomeres tend to get shorter with age, a process that may be associated with age-related cell breakdown and death. But the telomeres of the longest-lived group of bats, a genus called Myotis, do not appear to shrink with age. (See 16 incredible pictures that show the beauty of bats.)
Understanding why bats live so long, and how they remain healthy into old age, may help extend human life spans one day.
Superpower #4: Resistance to viruses
In addition to living longer, bats remain healthy throughout their lives, with very low incidences of cancer.
Furthermore, bats can be infected with otherwise deadly viruses, such as rabies and Ebola, without getting sick. To figure out how, scientists are studying bat genetics, which has revealed some clues. A recent analysis of six bat species’ genomes revealed a long-standing evolutionary arms race between bats and viruses. For instance, bat genes involved in immunity and inflammation periodically changed over time, likely in response to infection by viruses, which themselves evolved better ways to infect bats.
Bats are the suspected reservoir for several viruses that can infect humans, such as the Nipah virus, which is often fatal. While some experts suspect that SARS-CoV-2, the coronavirus responsible for the COVID-19 pandemic, originated in bats, others question whether bats are the direct culprits.
In any case, wild bats carrying coronaviruses do not pose a threat to humans if left undisturbed, conservationists say. What’s more, research into their unique immune systems may actually give insight into how people can live with viruses and not get sick.
Superpower #5: Keeping environments healthy
Beyond their own abilities, bats also bolster many other parts of their ecosystems.
Three out of every four bat species eats insects, and each night, any of these species can eat their body weight or more in insects. Many are pests that cause damage to important agricultural crops, such as cotton. Scientists estimate that insect-eating bats may save U.S. farmers about $23 billion per year by reducing crop damage and limiting the need for pesticides. (Read why some bats hunt during the day.)
Many bat species boost plant health and diversity: At least 549 plant species either are pollinated or dispersed by bats. Those include many popular food crops, including bananas, mangos, guavas, and cacao (the main ingredient in chocolate).
We can also thank bats for our cocktails. The lesser long-nosed bat, which ranges from Central America to the southwestern U.S., is critical for the pollination of the blue agave cactus, from which tequila is made. These same bats also pollinate the saguaro cactus, a well-known symbol of the Sonoran Desert.
“Bats are unsung heroes of biodiversity,” says Medellín. “They provide crucial services to ensure our food, clothes, and drinks. It’s about time we appreciate them.”