Masters of powered flight on a thin wing membrane is nothing short of miraculous in itself. Yet, the Nose leaf bat does it, and so does the blood-sucking Vampyrum spectrum bat.
No matter whether we discuss the Pteropus giganteus (Indian flying fox), Spectral bat, or the little Brown bat, their flight muscles are designed for precision.
They can make rapid, tight turns in mid-air in response to acoustic orientation, hover as they suck nectar from flowers, or glide over short distances as they view the world for prey.
Learn to love them because our future depends on their survival.
How Does Bats Look Like?
What do batslook like? From my perspective, they look a little like puppy dogs. Or, at least, their faces look like something between a puppy and a rat.
Bat ears can be large or small, depending on the species. They often have fairly large ears and big eyes (macrobats) filled with curiosity. Their torsos can be long or short, with short hind limbs and extended arms.
The long arms are adapted wings and hands with movable joints. The thin, fragile membrane connects these finger joints on the front limbs and the hind legs.
These flying mammals have short, dense fur all over their bodies. The color of this fur can be anything from black to brown, white, light orange, gray, red, or tan.
The bat’s underbelly is typically lighter than their backs. Some bats even have markings on their fur, like patches, stripes, or hair tips that are colored differently.
Natural History-Where Do Bats Come From?
Experts say that evidence of bats’ existence dating back about 51 million years is available. They have found fossils of bats in North America, Africa, Australia, and Europe that go back to the early Eocene epoch of the Cenozoic Era (roughly 33 to 54 million years ago).
Today, there are so many bat species that they make up 20% of all mammals across the world, second only to rodents. Like rodents, their sizes depend on the subspecies and vary greatly (more about that later)!
A long time ago, bats used to be known as the flittermouse, which has its origins in German and Swedish languages. This name was particularly suitable because it describes how bats flit about in the night sky. Another name for bats was Bakke, which has links with Natbakka or night bat in the Swedish language.
The Latin word for moth is Blatta, describing a nocturnal insect or moth. Experts believe that English people first started using the term bat in the 1570s. Additional background for the bat’s name comes from Ancient Greek in the form of Chiroptera, meaning hand wing.
Phylogeny and Taxonomy
Given below is an overview of the bat’s phylogeny and taxonomy.
Bats don’t make good fossils because of their delicate frames. But experts have found evidence of their existence about 50 million years ago. Evidence suggests they have not changed much physically, and the Archaeopteropus and Hassianycteris kumari looked very much like present-day microbats.
Studies suggest that the bat came from one genus of flying mammals or evolved from flightless insectivores. Current categorization places bats in the Chiroptera order, which has two suborders. The suborders are the Megachiroptera, or large Old World fruit bats, and the Microchiroptera, or small bats.
The Megachiroptera suborder consists of the Family Pteropodidae. This family includes Old World fruit bats and flying foxes.
The Microchiroptera suborder contains the following families that inhabit temperate and tropical climates:
- Family Vespertilionidae (Vesper bats)
- Family Phyllostomidae (American leaf-nosed bats, including Vampire bats)
- Family Rhinolophidae (Horseshoe bats)
- Family Hipposideridae (Old World leaf-nosed bats)
- Family Molossidae (Free-tailed bats)
- Family Emballonuridae (Sheath-tailed, or Sac-winged, bats)
- Family Nycteridae (Slit-faced or Hollow-faced bats)
- Family Mormoopidae (Leaf-chinned bats)
- Family Megadermatidae (False vampire bats)
- Family Natalidae (Funnel-eared bats)
- Family Rhinopomatidae (Mouse-tailed bats)
- Family Thyropteridae (Disk-winged bats)
- Family Mystacinidae (New Zealand short-tailed bats)
- Family Furipteridae (Smoky bats)
- Family Noctilionidae (Bulldog bats)
- Family Craseonycteridae (Hog-nosed or Bumblebee bat)
- Family Myzopodidae (Old World sucker-footed bat)
Scientific Classification of Bats
- Kingdom – Animalia
- Phylum – Chordata
- Class – Mammalia
- Clade – Scrotifera
- Order – Chiroptera
Here are suborders and species of bats, the only mammals capable of flying.
- Megachiroptera (megabats)
- Microchiroptera (microbats/echolocating bats)
Not all megabats are bigger than microbats. Several things distinguish these suborders. One is that microbats use echolocation and eat large insects, small vertebrates like frogs, mammals, blood, fish, pollen, and nectar. Microbats have ears that also don’t close in a ring shape.
Megabats don’t use echolocation because they have good eyesight. One megabat exception is the Rousettus genus which does use echolocation. Megabats also have a forelimb with a claw on the second finger. These bats like eating pollen, ripe fruit, and nectar, so they are excellent at dispersing seeds.
- Yinpterochiroptera (includes the megabat family and Rhinolophidae, Hipposideridae, Craseonycteridae, Megadermatidae, and Rhinopomatidae)
- Yangochiroptera (includes the other bat families, which use laryngeal echolocation)
Behavior and Life History
Here is an overview of bat behavior and its life.
Social Structure and Family Life:
Some live alone while others live in colonies. The social system may be a fission-fusion where large numbers of bats meet in roosting areas.
They can also create subgroups and socialize between these, including long-distance relationships between mothers and pups. Social behavior in these groups consists of mutual grooming and sharing food to strengthen bonding.
Bats communicate with hair, shoulder, or wing sac secretions. They also communicate via low-frequency or loud vocalizations, including singing like birds (Mexican tree-tailed bats), buzzes, trills, and chirps.
Most of these sounds are conventional. But bats vary these sounds in distinctive order, phrase repetition, and syllable numbers.
Reproduction and Lifecycle Nursery Colonies:
Many bat species are polygynous, monogamous, or promiscuous. Some breed late in summer or early autumn, leaving mating plugs in the females. Others mate with females during torpor.
Females from specific species can control the timing of their pregnancies or delay fertilization. Keeping the sperm alive can continue for long periods due to a specialized gas exchange system.
Mothers birth one bat pup a year and raise them in maternity colonies unless they belong to a monogamous species. In that case, the males will help raise the pup. In nurseries, females often help raise the young through all suckling.
Lifespan of Bats
Bats’ average lifespans are between 20 and 30 years. Also known as the Bumblebee bat, Kitti’s Hog Nosed bat has a lifespan of five to ten years. In contrast, the largest bat in the world, the Giant Golden-Crowned Flying Fox, lives for between 15 years (in the wild) and 23 years (in captivity).
One from Siberia (Brandt’s myotis) made history by living for 41 years in the wild.
Most bat species are active at dusk and dawn and throughout the night. This nocturnal behavior ensures they take advantage of ambient temperatures and low humidity to protect their delicate wings.
Nocturnal foraging also means other benefits, like avoiding daytime predators. Some nocturnal creatures are Vampire bats, Fishing or Bulldog bats, and Carnivorous bats, which are mainly microbats.
In contrast, a few species are adapted to forage during the day and roost at night. These include the Pteropus samoensis (Flying fox), Saccopteryx bilineata (Greater sac-winged bat), and the Lavia frons (Yellow-winged bat).
Bats can crawl, but they mainly fly. Some bat groups, like Free-tailed bats, fly better in open spaces and at high altitudes. These Free-tailed bats roost high in the trees because when they want to fly, they must first jump and lose height before they can fly.
Other bat groups, like Fruit bats, can hover, so they fly better in forests where they feed on nectar and fruit. These hovering groups include species like the Megadermatidae (False vampire bat) and Nycteridae (Slit-faced bats).
Depending on the wing design, bat species like the genus Macrotus can take off from the ground by flapping their wings. Others must jump into the air before they can fly, like Demodus (Vampire bat).
Unlike birds, bats maneuver better in the air. Also, their flight speeds range from almost 12 mph to nearly 21 mph, although this is difficult to record.
There are over 1,400 bat species, so it is safe to assume that their roosting preferences are diverse. Their roosting behavior also depends on the climate, weather, season, light, reproduction, and other reasons.
Roosting colonies can number in hundreds of thousands or be much smaller, like a few dozen or a handful. Bats can roost in the open or in trees.
But most bats like an isolated, secure roosting space. Bat roosts include caves, tree hollows, abandoned buildings, tree branches, rock surfaces, and elsewhere. Whatever the species, they want a safe place to rest and raise their bat pups.
Migration can depend on the weather, genetics, food sources, or a combination. Biologists think some pregnant and lactating female bats will migrate for abundant food sources and avoid competing with adult males for food.
Experts have found that female Mexican free-tailed bats migrate between Texas and central Mexico and surrounding states.
Other bat migrations include the N Lasiurus borealis and L. Cinereus (North American red and Hoary bats), and Lasionycteris noctivagans (Silver-haired bat) that migrate southwards in the fall to the warmer southern states and further south.
Microbats or Microchiroptera use echolocation or ultrasonic sounds to orient themselves and detect prey. Although they are not blind, the bats in this subspecies have small eyes and don’t have excellent eyesight.
Instead, they send out high-frequency pulses that bounce off objects. The quality of the echo-response gives the bat information about its surroundings, including if there are flying insects, predators, and other things around it.
The evolution of Rousette bats is so advanced that it has a separate echolocation system to avoid objects and another for everything else. The skulls, noses, and ears are all part of their orientation or echolocation systems. Unlike microbats, macrobats use their eyes, smell, and hearing to navigate their environments.
Anatomy and Physiology
Skull and Dentition
The head and teeth shapes of the different bats vary. Vampire bats have short snouts and mouths with prominent incisors, canines, and 20 teeth. The absence of enamel on the teeth keeps them sharp.
Mega bats have longer noses, big eyes, and small ears. Microbats have longer snouts for feeding on nectar. Insectivores have up to 38 teeth. Insectivores can have fewer teeth adapted to crush bugs and stronger lower jaws than bats that eat fruit.
Wings and Flight
Bats are capable of sustained flight. The wing membrane or patagium incorporates blood vessels, muscles, nerves, connective tissues, and elastic fibers. These wings are adapted across the types of bats to hover, glide, or fly for long distances.
Roosting and Gaits
When bats rest, they hang upside down by holding onto something with their feet. This behavior is known as roosting. Most bats have lateral gaits that allow them to move one after the other. They can move faster if they move their limbs in unison. Others can use their wings and legs to hop or crawl.
Bats have well-developed circulatory systems, venomotion to support rhythmic contraction of venous wall muscles and blood flow, a respiratory system designed to enhance powered flight, and digestive systems that are specific to their diets.
Their senses include echolocation in some species, which allows them to bounce signals off objects. Bats that don’t have echolocation have excellent vision. All bats use magnetoreception, ensuring they can distinguish between north and south.
Some bats have a stable body temperature, whereas it varies in others. They use thermoregulation to adapt their body temperature as needed. Other bats use torpor, a semi-hibernation state, for many reasons, including saving energy.
Bat sizes depend on the species. Wingspan can range from slightly more than an inch to over five feet. Their body shapes, sizes, and weights also differ.
The distribution of bat species is worldwide. Bats live everywhere except in the icy polar regions of the Arctic and Antarctic and high mountains. Experts also say you are unlikely to find bats on isolated sea islands.
These mammals favor sub-tropical and tropical regions and warmer areas. Because they prefer warmer regions, they live in most areas, including North and Central and South America, Europe, Australia, Africa, and Asia.
Large colonies live in caves or in hollow trees, rock crevices, mines, buildings, and habitats where they like roosting.
Ecology of Bats
Keep reading to learn more about bat ecology.
Food and Feeding
Vampire bats suck the blood of animals and sometimes people, which is pretty unpleasant. They choose an area and latch onto the animal’s skin near its anus, ear, or nostril. Then they make a small incision and suck about 15mm of blood.
Other species, like insectivorous bats, eat flying insects. They track them with echolocation and capture them in flight in their wing membranes. These bats also eat arthropods on the ground, walls, or vegetation. They hover above the prey and kill them with their teeth.
Some bats catch fish and eat crustaceans. The same types of bats (Myotis and Noctilia) may also eat flying insects. These bats have large claws on big hind feet, which are ideal for grasping their meals.
Other bats are frugivores, which eat pollen, and nectar from flowers that hang away from the tree bark. These flowers are often white and have unpleasant characteristics like rancid, sour, musky, or mammalian odors.
Many bats are generalists and will eat anything, but there are also certain species that are carnivores. These bats feed on birds, lizards, other bats, rodents, and shrews.
Predators, Parasites, and Diseases
Some bat predators and diseases are:
- Predators: Besides humans, bat predators can include domestic cats, hawks, raccoons, or owls.
- Internal parasites: This includes Gastrointestinal (GI) parasites
- External parasites: These include fleas, ticks, parasitic bat flies, bat bugs, chiggers, and mites.
- Fungus: White-nose syndrome (WNS – Pseudogymnoascus destructans), Histoplasmosis Laboulbeniales
- Viruses: Hantaviruses, Ebola, Hendra
- Zoonotic diseases: Histoplasmosis, salmonellosis, yersiniosis, Ehrlichia sp., and Rickettsia africae. Some bats also carry rabies disease but not more so than other mammals.
- Bacteria: Leptospirosis
Awesome Facts about Bats
- There is a cave in Texas called the Bracken Bat Cave. The biggest bat colony in the world lives in this cave. The Mexican free-tailed bat species flies here from Mexico to roost between March and October yearly.
- Bats are not blind, but some microbat species have small eyes, so they use their echolocation to “see” instead of their eyes.
- Flying foxes are mainly fruit-eating bats. They are also tropical bats that live in South Asia, Southeast Asia, Australia, East Africa, and some Indian and Pacific Ocean islands. It is not a picky food eater but mostly lives on fruit.
- Pallid bats feast on North America’s Arizona bark scorpion. It is the most venomous scorpion, but the Pallid bat seems immune to its venom.
- Bat wings have tiny Merkel cells in the form of bumps. Each bump contains tiny hair. As the bat flies, these hairs pick up environmental clues, assisting the bat in flying better.
- Mexican free-tailed bats are the fastest mammals in the world. Recent studies show they can reach speeds of up to 100 mph.
- Without bats pollinating fruit, you won’t have avocados, mangos, or bananas.
- Insectivorous bats eat over 1,200 mosquitoes every hour.
- Most bat species eat their body weight every night.
- Scientists have found bats frozen in ice that have survived.
- Not all bat species hibernate.
- The common little Brown bat in North America has the longest lifespan of any mammal for its size, living up to 32 years or more.
Interactions with Humans
Given below is more information about bats and their relationship with humans.
When it comes to culture, bats may be symbolically linked with positive traits, such as prolonged life, rebirth, and safeguarding against certain diseases or risks. Some cultures associate bats with joy, like the Chinese. Others use it as their state symbols.
In the West, bats are often analogous to all things evil, like malice, vampires, witchcraft, and death. Others believe the bat is a messenger from beyond the veil.
National Geographic wrote that Hernan Cortez traveled to Mexico from Spain in 1519. On his arrival, vampire bats sucked the blood of their horses. This news reached Spain and Europe, and these mammals became a part of Bram Stoker’s vampire stories.
Since then, storytellers and Hollywood have made the Vampires and other bats something fearful.
Because bats control insect pests, they save the U.S. agricultural community between $4 and $53 billion annually in pesticides and crop damage.
Another benefit of bats is that using fewer pesticides means less environmental damage and spending less money on restoring the environment. Pesticides also create insect resistance, which is why bats are vital to the economy and our survival.
Another economic benefit of bats is that their guano is exceptionally nutrient-rich. Because of this, it is a valuable fertilizer for home gardens and lawns.
Bats consume large numbers of insects in just one night, ensuring natural population control. Because they control insect numbers, they also limit the spread of diseases carried by insects, such as the West Nile virus. Bats are also valuable in controlling insects that eat crops, such as leafhoppers, moths, and beetles.
Besides pest control, fruit eaters are nature’s conservationists because of seed dispersal and pollination. Both these acts support the natural ecology of their environments, securing sustainable growth of their food sources and ours.
According to the IUCN, about 40% of bats are endangered or threatened with imminent extinction. This organization also states that most bats are data deficient. This description means they need more conservation to help the species survive and thrive.
Over half the bat species in the U.S. have been declining for years, so they are on the IUCNs list of endangered species. Examples of endangered bats include the Little Brown bat and many other bats. Examples of declining species are the big Brown bat and the Indiana bat.
One example of an endangered bat in Central and South America and Mexico is the Leaf-nosed spectral bat, which is exclusively carnivorous. It is on the IUCNs list as a near-threatened species due to its low population numbers.
Bats face threats from habitat loss, windmill turbines, pesticides, and climate change. Additional threats to their populations are diseases like white-nose syndrome, which is a fungus. Windmill turbines primarily threaten three species, the Tricolored bat, the Hoary bat, and the Silver-haired bat.
Why Bats Aren’t as Scary as You Think
National Geographic describes how significant bats are for the environment and our economies. Bats pollinate different fruits and are essential because they spread seeds that help to regrow rainforests and orchards. Without them, our food sources decline.
They are also responsible for keeping insect populations in check. Otherwise, crops would fail without bats eating large insects and small insects that feed on food on farmlands.
Learn to love them because their benefits far outweigh any negatives they may have or you think they have. Like bees, we depend on them to help grow our food and to survive.
What Can You Do to Help the Bat Colony?
You can take several steps to protect bats in your area, like the following:
- Plant a garden that attracts insects that bats love to eat
- Erect a bat house where they can live and thrive
- Make your home bat friendly
- Do not use pesticides in your garden
- Avoid entering caves and potentially disturbing bat colonies or spreading white-nose syndrome
- Educate yourself by reading as much as possible about bats
- Please share what you learn with others so they can help save bats
- Give your support to conservation organizations that specialize in preserving bats
- Are bats mammals? Bats are mammals that fly and are the only flying mammals on earth.
- How many species of bats are there? More than 1,400 bat species live on earth.
- How big are bats? The smallest bat is the Kitti’s Hog Nosed, which has a body weight of two grams (1.1 to 1.3 inches long – a wingspan of 6 to 7 inches). The largest is the Giant Golden-Crowned Flying Fox which weighs 1,300 grams or three pounds (11 inches long – a wingspan of 5.5 feet).
- What is a group of bats called? The collective term is a colony or a camp of bats.
When you think of the bat’s thin wing membrane, it’s incredible it can fly at all. But they do. More than that, they are natural conservationists who do good for the environment by spreading seeds, growing forests, and boosting country economies by keeping insect populations down.
Instead of fearing them, we should all protect them and their habitats to leave a healthy planet for our children. It starts here and continues with further education. Protect bats for yourself and your world!