Bats
Bats are one of the largest groups of mammals on the planetwith around 1,300 recognized species in the order Chiroptera. They come in various shapes and sizesfrom the tiny bumblebee bat that weighs less than two grams to the flying foxwhich has a wingspan of up to 1.5 meters. Aside from polar regions and extreme desertsbats can be found almost anywhere on Earthas they live off a wide range of dietsfrom the blood of large animals to flying insectsfruitand even fish.
Though there are many bat species—and some have very large populations—these mammals have some of the slowest reproduction rates in the animal kingdom. Females typically give birth to just one pup per year—but when 100 million females gather to give birththat still results in a very large number of baby bats.
Bats and bat pups are indicators of a healthy ecosystem and help to maintain its balance. Insect-eating bats control insect populationswhile fruit-eating bats disperse seeds and pollinate flowers.
What is a bat’s scientific name?
The scientific name for bats is Chiropterawhich means ‘hand wing’ in Greek. This name refers to a bat’s long fingerswhich are connected by a thin membrane to form their wings.
Though there are over 1,300 species of batsthey all fit into two main types: microbats and megabats. The former can live nearly anywhere and mostly feed on insects or bloodwhile the latter live in the tropics and survive on a diet of fruitnectarand pollen.
Are bats endangered?
There are many species of bateach with their own conservation status. While some bat species are classed as ‘least concern’others are critically endangered or have already gone extinct.
Critically endangered bat species include the Seychelles sheath-tailed batwhich has a population of fewer than 100 mature individuals; Livingstone’s flying foxwhich has around 1,300 mature individuals; the New Caledonia long-eared batwhich has between 150 and 250 mature individuals; and the Thongaree’s disc-nosed batof which accurate population numbers are unknownthough the population is reportedly decreasing.
The Bonin Pipistrellewhich was last seen in 1889; the Guam flying foxwhich was last observed in the 1960s; and the Lord Howe long-eared batwhich was last seen in 1972are all classed as extinct.
Where do bats live?
Bats are found worldwideexcept in polar regions and extreme deserts. They live in forests and wetlands as well as urban areas. During the daythey rest in shelters known as roostswhich include cavesminesold buildingsand hollowed trees. To stay protected and out of sightbats usually rest in small cracks and crevicesmaking it difficult for researchers to find them and learn about their roosting spots. They also rest upside down so they can drop quickly and fly away if needed. Bats that live in temperate climates tend to migrate in the winter to a cool roost where they can hibernate—some caves end up providing space for millions of bats to hibernate together.
There are over 100 species of bats in Africa and around 45 in the US. The UK only has insect-eating bat species. In totalthere are around 829 known species that live in forests496 that live in caves247 that live in urban areasand 188 that live in savannahs.
Threats
Bats face a number of threatsmany of which are due to human activity. Climate changehabitat losshuntingand wind energy all increase bat mortality and are perpetuated by humans. Bats also struggle to recover from population decreases because of their slow reproduction rates and the effects of white-nose syndrome.
Climate change
Climate change affects ecosystems in extensive and unpredictable waysso it’s difficult to know exactly how bats might be affected. It’s thought that bat mortality may be affected by the increased severity and frequency of natural disasters like droughts and heat waves. In drier climatesincreased aridity might affect the survival and reproductive success of bat speciesand changes in weather patterns worldwide might affect migration timing and food availability during bats’ journeys.
Habitat loss
Forests and tropical rainforests are bats’ main habitatsbut these areas are experiencing high levels of human disturbancedevelopmentand deforestationreducing the amount of space available to these mammals.
Mines and caves where bats hibernate are also disturbed by miners and tourists. This is extremely destructiveparticularly between November and Maywhen bats hibernate. These disturbances can prematurely wake bats from hibernationcausing them to quickly burn through their fat stores and risk starvation.
Hunting
Bats are incorrectly labelled as disease spreaders in many parts of the worldwith some cultures associating them with vampirism and evil. This can lead to unnecessary killings in areas like Latin Americawhere all three species of vampire bats live. Alsoin Southeast Asiafruit bats and flying foxes are hunted for meat and used in traditional medicine.
White-nose syndrome
White-nose syndrome (WNS) is a fungal infection that affects numerous species of bats in the US and Canada. A fuzzy white substance grows on the nosesearsand wings of infected bats. Much is still unknown about the diseasebut it appears to cause irrational behavior in batssuch as flying during the day or in cold temperatures and waking up during hibernation. The disease is causing significant population declinesmostly in hibernating species. The Northern long-eared bat (also known as the Northern myotis)native to Canada and the UShas become endangered specifically due to the effects of WNS.
Wind energy
Although wind energy is a positive development in the fight against climate changewind turbines present a significant threat to migratory bat species. Bats are prone to colliding with the turbine bladesand death estimates are in the hundreds of thousands in the US alone. To minimize the risk to batsit is necessary to research and develop protective measures that reduce collisions.
FAQs
Are bats blind?
Despite the famous phrase ‘as blind as a bat’bats aren’t actually blind. Many species have advanced vision that’s attuned to low light and helps them hunt in the dark.
Bats are associated with blindness because they’re nocturnal and because they use sound to locate their prey. Over timethis ability to ‘see’ with their ears became associated with an inability to see with their eyes.
What do bats eat?
Food habits vary between the 1,300 species of batbut the most popular food choice is flying insects. The types of insects they eat depend on the regions they live inbut they don’t hunt for specific species—they eat whatever comes their way. Some species also eat larger invertebrates like spiders and scorpions. Other species have extra-large feet and claws for catching fish and crustaceans. Megabats eat fruitusually ones that grow on treesand some fruit bats also eat pollen and nectar. Other types of bats are carnivorous and eat small rodentsbirdsfrogsand lizards. Vampire bats live off the blood of large mammals and birdsdrinking around 15 milliliters of blood per night.
Are bats mammals?
Bats are the only flying mammals. They are one of the largest groups of mammalssecond only to rodents (the order Rodentia contains over 2,000 species).
Do bats hibernate?
Bats that live in temperate climates and live off food sources like insects and fruit that dwindle during winter go into hibernation during colder months.
Hibernation spots need to have a coolstable air temperature. Cavesminestunnelsand cellars serve as popular bat hibernation sites. There also needs to be high humidity to decrease bats’ chances of dehydrationbut they can wake up and drink water when the weather is a little warmer. When they hibernatebats breathe as little as once per hourand their hearts beat only 10 times per minute.
Are bats rodents?
Although bats are sometimes nicknamed ‘flying rodents’ or ‘rats with wings’they’re not rodents and aren’t related to rats or mice. It’s difficult to gather information on bat evolution and their relatives because bat bones are so small and delicate that they don’t fossilize well. Howeverit’s currently believed that bats are part of a superorder that includes animals as varied as pangolins and whales.
Are bats birds?
Bats are not birdsthey’re mammals—the only mammals that can fly. While there are some mammals that can glidesuch as the flying squirrelbats are the only ones with wings that are capable of true flight.
What is a group of bats called?
A group of bats is known as a colony. This might be because bats gather in large numbers in the same locationsuch as the Mexican free-tailed bats that gather in five large caves in Texas in groups of 100 million.
Why do bats hang upside down?
There is a theory that hanging upside down is the safest position for bats to rest in because they can react to danger and fly away more quickly. When flying animals take off from the groundthey need a small run-up to achieve lift and overcome gravity. Bats can’t runhoweverso it’s not possible for them to take off from a standing position. Insteadthey hang upside down from a high placelet goand spread their wings to begin flying.
Are bats dangerous?
Bats are shy creatures that tend to stay away from humanseven when they live in urban areas. Most of the timeyou’ll only see bats flying around outside during the nightand you won’t experience many close encounters. If you do see a bat in close quartersit’s important to remember that they’re wild animals that can attack if they feel threatened. Many species have claws and teeth that are strong enough to pierce human skinand there’s a small chance this could spread diseases like rabies.
Do bats have tails?
Most bats have tails that support the wing membrane that extends between their legs. This tail varies in length depending on the species. Howeverthere is a genus named Anoura which is known as the tailless bat. These bats either have no tail or a tail shorter than one centimeter.
How long do bats live?
Life expectancy varies between species but most bats live less than 20 years in the wildwith six species known to live longer than 30 years. The oldest known bat lived for 41 years in Siberia.
Do bats lay eggs?
Despite their wings and ability to flybats are mammalswhich means they give birth to live young rather than laying eggs. Mothers nurse their young with milk until they’re ready to hunt for themselves.
Do bats migrate?
Bat species that prefer temperate climates migrate each year between summer roosts and winter hibernation sites. Scientists don’t yet know how bats learn where to migrate or how they navigate during the journey. When female Mexican free-tailed bats migratescientists believe they’re travelling to regions with higher food availability where they don’t have to compete with males to feed themselves and their young.
What sound does a bat make?
Bats make sounds when they use echolocationeither by contracting their voice box or clicking their tonguedepending on the species. Some types emit the sounds through their mouthswhile others use their noses. Most echolocation calls aren’t audible to humans because they’re ultrasonicmeaning they exceed the 20-kilohertz frequency limit that human ears can pick up. We can hear some callsthoughsuch as the echolocation clicks from the spotted batwhich sounds like someone hitting two pebbles together.
Do bats eat mosquitoes?
Many bat species eat flying insects as a part of their dietincluding mosquitoes. Bats use echolocation to seek out their prey mid-flight and then use their wings to interrupt the insect’s flight path and catch them. They can also land on insects that sit on walls or vegetationpicking them up with longstrong claws. Mosquitoes are just one of many types of insects that bats can eat—they don’t hunt specifically for mosquitoes.
Our work
IFAW is part of multiple projects that help to protect bats.
At Two Thumbs Wildlife Trust Sanctuaryimportant tree hollows that took between 100 and 200 years to develop were destroyed by devastating bushfires in 2020. IFAW is working to provide the recovering area with specially designed nest boxes that mimic tree hollows and provide instant new homes for hollow-dependent bat speciesamong other animals.
IFAW is also working with the Ukrainian Bat Rehabilitation Centre to help rescue bats in Ukrainewhere the ongoing war is causing significant disruptions to their hibernation. IFAW equipped the center with batteriesa back-up driveand extra crates so that they could continue their work despite electricity shortages after the attacks on the Ukrainian energy infrastructure. We also supported training for the bat rescue network in 2023 and the construction of new hibernation facilities for rescued bats. The rehabilitation center succeeded in rescuing a hibernating colony of 576 bats from an underground location near Kyiv.
How can you help?
Bats around the world face threats of climate changehabitat losshuntingand wind energy.