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Bats-The Only Flying Mammal
To many people bats are ugly, live in dark caves, are associated with creatures of the night, suck blood, and in general are a nuisance to man.
But, is that viewpoint really accurate? Let`s look at what bats are, and whether they are good for man, or bad.
There are more than a thousand bat species worldwide. They are the only flying mammals, and are in the order Chiroptera. An important point is that over two thirds of bats are insectivores, and help to keep down the numbers of insects which can cause damage. Most other bats are fruit eaters. And, not widely known, is that many bats are valuable in flower pollination, and the dispersal of plant seeds, including a variety of tropical plants.
Basically, bats are small, winged, furry creatures whose body resembles that of a mouse. In fact, the Germans call the bat Fledermaus, meaning `flying mouse.` Among mammals, bats alone can fly. There are other mammals that can glide, such as the so-called flying squirrel, but they can not fly.
Depending on the species, a bat`s face may resemble a bear, a dog, or maybe a fox. One is called the horse-headed bat, for obvious reasons. In some cases, the nose has a growth on it-perhaps one looking like a leaf. Sensory nerve endings are found in those growths.
Bats` colors vary greatly. Many of them are brown, gray or black. But there are variations. For instance, the ghost bat is white, maybe with some gray mixed in. There is a fruit-eating bat with a blackish head and dark-brown wings with yellow spots.
How do bats fly?
Their wings consist of thin skin. It stretches from their front limbs along each side of our bodies to their hind legs. The skin or membrane runs between their five digits, that is, the four fingers and thumb.
They usually roost by hanging upside-down by their feet. Generally, they `take off` merely by dropping from a roosting place. They just spread their wings and they are flying. They can also take off just as easily from a level place.
When it comes to wingspan, there certainly are big differences among bats. For instance, the little brown bat, with a body under 10 centimeters long, can spread its wings to 35.5 centimeters. The smallest known bat is the Kitti`s hog-nosed bat. Sometimes they are referred to as the bumblebee bat because of its size. Kitti`s hog-nosed bats are to be found mainly in the Sai Yok National Park in Thailand. Amazingly even though they really are tiny, weighing around two grams and being only around 30 millimeters long, their wingspans are approximately 13 centimeters!
However, the prizewinner is the flying fox, so named for its looks. These dark-brown bats that inhabit most of the tropics, other than South America, have a wingspread that may exceed 1.5 meters! To turn in flight, or to stop, the little brown bat moves its tail downward, making it act like a brake. The lump-nosed bat flies slowly, but it can also hover over something of interest.
Bats` habitats
It`s true that millions do roost in deep, pitch-black caverns. But, some of them roost in trees, various buildings, ancient temples-yes, and in tombs, too. Others take over vacant bird nests and animal burrows. Bats also live in bell towers and church steeples.
What they eat
Insect eaters are the most numerous. Generally, they catch their prey in flight. Fruit eaters are tropical bats mostly dependent upon wild fruit, though they are known to cause great damage to orchards. Some bats are small flower feeders with long tongues. Pollen and nectar are their fare. Lizards, frogs, small mammals and birds are on the menu of moderate-sized carnivorous bats, although they also eat other things. Then there are the fish eaters. Their powerful feet have hooked claws capable of snatching prey near the surface of the water.
What about the infamous vampire bat?
Who has not heard the fictitious tales about dead people who supposedly rise from their sepulchers at night, transform themselves into bats, and suck the blood of hapless humans. You know the old vampire story. Well, mainly in the tropical and subtropical regions of America there such creatures as vampire bats. They do feed on blood, sometimes that of sleeping humans.
The vampire bat has razor-sharp teeth. In fact, they`re so sharp that the bite is just about painless and the sleeping animal or human rarely is awakened by it. Maybe for some twenty minutes or so this bat gorges itself, taking in so much blood that its little body becomes spherical before the meal is over.
Actually, the amount of blood lapped up (not sucked) is not so great as to endanger humans. But there is another peril. Vampire bats may have rabies. So, left unchecked, their bites can result in hydrophobia and death. Vampire bats also transmit other diseases, such as murrina, which affects livestock. These little bats are dangerous, too, because their bites can cause secondary infection.
And it isn`t just vampire bats that can carry rabies. Never handle a bat, if you see one in the home look for signs that are out of the ordinary, such as seeing one during the daylight, which would be unusual, as they are nocturnal creatures by habit. If you think you or someone else has been bitten get checked over by a doctor.
Always harmful?
Bats are not always harmful villains. Some serve a useful purpose in helping to control the insect population. Others unwittingly carry pollen from flower to flower. Then, too, bat manure, or guano-plentiful on the floors of bat caves-can be used as fertilizer. Did you know that for two decades guano for fertilizer was acquired in commercial amounts from the noted Carlsbad Caverns in New Mexico?
During the American Civil War, from guano the Confederate Army got niter (sodium nitrate) for gunpowder. For that matter, while World War II was raging, there was some effort made to use certain bats to carry little incendiary bombs.
In some places, like northern India, those bats called flying foxes are eaten. People say their meat resembles that of chicken. Bats are also on the menu of certain types of snakes, birds of prey and other creatures (even some bats).
And bats are by no means unclean. They groom themselves every morning and after each meal. In grooming, they use their tongue and toes. They usually just reach up with one of their hind limbs and scratch the back, face and top of the head.
Bats` uniqueness!
Some of them hibernate. The bat is warm-blooded while active but cold-blooded while slumbering. It is able to go into hibernation more quickly and easily than other mammals which is why it can so readily be put in the refrigerator. (Some bats are kept there in research laboratories.) It just drops its body temperature and falls asleep; the heart slows from 180 beats a minute to three, respiration drops from eight breaths a second to eight per minute. While the bat has some accumulated fat (as it ordinarily has in early fall before winter hibernation) it can live for months in cold storage, unfed and unattended.
Those bats which do not hibernate in caves or elsewhere during the wintertime migrate to places where they can find food.
Some of pregnant females get together in maternity colonies. Noctule bats are a good example of this. Sometimes as many as four hundred of their pregnant females get together and set up `maternity wards` in buildings or trees. Furthermore, some female bats evidently store male sperm. In many cases, they mate in the fall and hibernate during the winter, but the females don`t ovulate until the next spring, permitting fertilization to take place at that time.
Bats` Echolocating System
Forget the expression "as blind as a bat." Bats are certainly not blind and some see very well. Even in pitch dark conditions bats can `see` using a method called echolocation, which even the scientists struggle to fully understand.
As bats fly about, they emit squeaks, chirps, clicks, buzzes and the like through their mouths or noses. Since these sounds range from 25,000 to 70,000 vibrations a second, us humans with an auditory range up to only about 30,000 vibrations can `t hear most of the sounds. But, bats don`t hear their own sounds either, because when they are sent out their ear muscles contract, momentarily turning off the sound. What they do hear is the echo that bounces off any object that happens to be in their path. In that way, even in total darkness, they can maneuver so as to avoid obstacles.
Some think it is possible that each animal has its individual sound pattern and is guided only by its own echoes. Otherwise, it would seem, there would be complete confusion from the echoes of several hundred bats moving in a flock.
Unfortunately there are many misconceptions which have grown up about bats. Getting more acquainted with them can dispel some of the myths, and help us to live in harmony with these unique flying mammals that are such an important part of the ecosystem.
In many parts of the world bats are a protected species. One organization which is devoted to bat conservation, education, and research initiatives involving bats and the ecosystems they serve is Bat Conservation International (BCI).
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