Bat

Newborn bats rely on the milk from their mother. When they are a few weeks old, bats are expected to fly and hunt on their own. It is up to them to find and catch their prey, along with satisfying their thirst.

Hunting

Most bats are nocturnal creatures. Their daylight hours are spent grooming and sleeping; they hunt during the nighttime hours. The means by which bats navigate while finding and catching their prey in the dark was unknown until the 1790s, when Lazzaro Spallanzani conducted a series of experiments on a group of blind bats. These bats were placed in a room in total darkness, with silk threads strung across the room. Even then, the bats were able to navigate their way through the room. Spallanzani concluded the bats were not using their eyes to fly through complete darkness, but something else.

Spallanzani decided the bats were able to catch and find their prey through the use of their ears. To prove this theory, Spallanzani plugged the ears of the bats in his experiment. To his pleasure, he found the bats with plugged ears were not able to fly with the same amount of skill and precision they were able to without their ears plugged.

Bats seem to use their ears to locate and catch their prey, but how they accomplish this was not discovered until the 1930s, by Donald R. Griffin, a biology student at Harvard College at the time. He discovered bats use echolocation to locate and catch their prey. When bats fly, they produce a constant stream of high-pitched sounds only bats are able to hear. When the sound waves produced by these sounds hit an insect or other animal, the echoes bounce back to the bat, and guide them to the source.

The Philippines Bat Image Gallery This bat flies on top of the Muntingia attracted by its sweet red fruits. Giant golden-crowned flying fox hoves over the Aratiles Bats of the Philippines hunt foods, particularly fruits, flying at nights.

Feeding and diet

The majority of food consumed by bats includes insects, fruits and flower nectar, vertebrates and blood. Almost three-fourths of the world’s bats are insect eaters. Insects consumed by bats include both aerial and ground-dwelling insects. Each bat is typically able to consume one-third of its body weight in insects each night, and several hundred insects in a few hours. This means a group of one thousand bats could eat four tons of insects each year. If bats were to become extinct, the insect population is calculated to reach an alarmingly high number.

Vitamin C

In a test of 34 bat species from six major families of bats, including major insect- and fruit-eating bat families, bats in all tested families were found to have lost the ability to make vitamin C, and this loss may derive from a common bat ancestor, as a single mutation.

Aerial insectivores

Watching a bat catch and eat an insect is difficult. The action is so fast that all one sees is a bat rapidly change directions, and continue on its way. Scientist Frederick A. Webster discovered how bats catch their prey. In 1960, Webster developed a high-speed camera that was able to take one thousand pictures per second. These photos revealed the fast and precise way in which bats catch insects. Occasionally, a bat will catch an insect in mid-air with its mouth, and eat it in the air. However, more often than not, a bat will use its tail membrane or wings to scoop up the insect and trap it in a sort of "bug net". Then, the bat will take the insect back to its roost. There, the bat will proceed to eat said insect, often using its tail membrane as a kind of napkin, to prevent its meal from falling to the ground.

Forage gleaners

These bats typically fly down and grasp their prey off the ground with their teeth, and take it to a nearby perch to eat it. Generally, these bats do not use echolocation to locate their prey. Instead, they rely on the sounds produced by the insects. Some make unique sounds, and almost all make some noise while moving through the environment.

Fruits and flower nectar

Fruit eating, or frugivory, is a specific habit found in two families of bats. Megachiropterans and microchiropterans both include species of bat that feed on fruits. These bats feed on the juices of sweet fruits, and fulfill the needs of some seeds to be dispersed. The fruits preferred by most fruit-eating bats are fleshy and sweet, but not particularly strong smelling or colorful. To get the juice of these fruits, bats pull the fruit off the trees with their teeth, and fly back to their roosts with the fruit in their mouths. There, the bats will consume the fruit in a specific way. To do this, the bats crush open the fruit and eat the parts that satisfy their hunger. The remainder of the fruit, the seeds and pulp, are spat onto the ground. These seeds take root and begin to grow into new fruit trees. Over 150 types of plants depend on bats in order to reproduce.

Some bats prefer the nectar of flowers to insects or other animals. These bats have evolved specifically for this purpose. For example, these bats possess long muzzles and long, extensible tongues covered in fine bristles that aid them in feeding on particular flowers and plants. When they sip the nectar from these flowers, pollen gets stuck to their fur, and is dusted off when the bats take flight, thus pollinating the plants below them. The rainforest is said to be the most benefitted of all the biomes where bats live, because of the large variety of appealing plants. Because of their specific eating habits, nectar-feeding bats are more prone to extinction than any other type of bat. However, bats benefit from eating fruits and nectar just as much as from eating insects.

Vertebrates

A small group of carnivorous bats feed on other vertebrates and are considered the top carnivores of the bat world. These bats typically eat a variety of animals, but normally consume frogs, lizards, birds, and sometimes other bats. For example, one vertebrate predator, Trachops cirrhosus, is particularly skilled at catching frogs. These bats locate large groups of frogs by distinguishing their mating calls from other sounds around them. They follow the sounds to the source and pluck them from the surface of the water with their sharp canine teeth. Another example is the greater noctule bat, which is believed to catch birds on the wing.

Also, several species of bat feed on fish. These types of bats are found on almost all continents. They use echolocation to detect tiny ripples in the water’s surface to locate fish. From there, the bats swoop down low, inches from the water, and use specially enlarged claws on their hind feet to grab the fish out of the water. The bats then take the fish to a feeding roost and consume the animal.

Blood

A few species of bats consume blood exclusively as their diet. This type of diet is referred to as hematophagy, and three species of bats exhibit this behaviour. These species are the common, the white-winged, and the hairy-legged vampire bats. The common vampire bat typically consumes the blood of mammals, while the hairy-legged and white-winged vampires feed on the blood of birds.

Results of eating

Bats' dung, or guano, is so rich in nutrients that it is mined from caves, bagged, and used by farmers to fertilize their crops. During the U.S. Civil War, guano was used to make gunpowder.

To survive hibernation months, some species build up large reserves of body fat, both as fuel and as insulation.

Drinking

Generally, bats drink water. In 1960, Frederic A. Webster discovered how bats are able to acquire this water. To do this, Webster developed a high-speed camera and flashgun that could take 1000 photos per second. Webster's camera captured the bat's method of skimming the surface of a body of water, and lowering its jaw to get just one drop of water. It then skims again to get a second drop of water, and so on, until it has had its fill of water. Its precision and control is very fine, and it almost never misses. Other, such as the flying fox or fruit bat, gently skim the water's surface, then land nearby to lick water from their chest fur.

Conservation efforts

Through conservancy efforts of groups such as the Organization for Bat Conservation and Bat Conservation International, bats are becoming better understood and people beginning to understand the crucial role bats play in insect control and pollination.

In the United Kingdom, all bats are protected under the Wildlife and Countryside Acts, and even disturbing a bat or its roost can be punished with a heavy fine.

In Sarawak, Malaysia, bats are protected species under the Wildlife Protection Ordinance 1998 (see Malaysian Wildlife Law). The large naked bat (see Mammals of Borneo) and greater nectar bat are consumed by the local communities.

Bats can be a tourist attraction. The Congress Avenue Bridge in Austin, Texas is the summer home to North America's largest urban bat colony, an estimated 1,500,000 Mexican free-tailed bats, which eat an estimated 10,000 to 30,000 pounds of insects each night. An estimated 100,000 tourists per year visit the bridge at twilight to watch the bats leave the roost.

Artificial roosts

Many people put up bat houses to attract bats just as some put up birdhouses to attract birds. Reasons for this vary, but most centre around the bats being the primary nocturnal insectivores in most, if not all, ecologies. Bat houses can be made from scratch or from kits, or bought ready made. Plans for bat houses exist on many web sites, as well as guidelines for designing a bat house. Some conservation societies give away free bat houses to enthusiasts worldwide.

Constructed in March 1991, the University of Florida bat house is the largest occupied artificial roost in the world. The bat house has an approximated 300,000 insect-eating residents. These bats can eat upwards of 2.5 billion bugs (2,500 pounds or 1,100 kilograms) per night.

A 1987 fire caused a colony of bats residing in Johnson Hall's attic to become homeless. This forced them to move to the James G. Pressly Stadium on the north side of campus. The odour and the guano from this newly arrived colony did not please spectators, thus furthering the movement for a new bat-ordained structure. In September 1991, thousands of bats were captured and transported to the newly built bat house. In the following evenings, these bats flew away, and found new homes. For three years the bat house remained empty. Finally, in 1995, the bats moved in permanently, and the colony continued to grow. The colony grew so much, that in 2009, part of the original bat house collapsed, and a new “Bat Barn” was constructed next to it. Along with that, the interior of the original was rebuilt.

In Britain, British hardened field defences of World War II have been converted to make roosts for bats. Pillboxes that are well dug-in and thick-walled are naturally damp and provide the stable thermal environment required by bats that would otherwise hibernate in caves. With a few minor modifications, suitable pillboxes can be converted to artificial caves for bats.

Again in the UK, purpose-built bat houses are occasionally built when existing roosts are destroyed by developments such as new roads; one such has been built associated with bat bridges on the new (2008) A38 Dobwalls bypass.

Threats

While conservation efforts are in place to protect bats, many threats still remain.

White nose syndrome

White nose syndrome is a condition associated with the deaths of more than a million bats in the northeastern United States. The disease is named after a white fungus, Geomyces destructans, found growing on the muzzles, ears, and wings of afflicted bats. This fungus, which can be spread from bat to bat, is the sole cause of the disease. Mortality rates of 90–100% have been observed in some caves. At least six species of hibernating bats are affected, including the endangered Indiana bat. The cause of death in these species is due to two factors. The fungus desiccates the wings of the animal upsetting its hydrostatic balance during hiberation. It loses water more quickly and thus must go out more often to drink and maintain hydration. This drains its energy stores and because of a lack of food in the winter, leaves it either dead or severely emaciated when it emerges from hibernation. Because the affected species have long lifespans, and birth rates of only about one offspring per year, populations are not expected to recover quickly.

Barotrauma and wind turbines

Although sounds or vibrations emitted from wind turbines have no adverse effect on human health, evidence suggests barotrauma is causing bat fatalities around wind farms. The lungs of bats are typical mammalian lungs, and unlike the lungs of birds, they are thought to be more sensitive to sudden air pressure changes in their immediate vicinity, such as near wind turbines, and are more liable to rupture. Bats suffer a higher death rate than birds in the neighbourhood of wind turbines. Since there are no signs of external trauma, the cause has been hypothesized to be a greater sensitivity to sudden pressure fluctuations in the mammalian lung than in that of birds. In addition, it has been suggested that bats are attracted to these structures, perhaps seeking roosts, and thereby increasing the death rate.

Pathogens and role in the transmission of zoonoses

Among ectoparasites, bats occasionally carry fleas, but are one of the few mammalian orders that cannot host lice (most of the others are water animals).

Bats are natural reservoirs for a large number of zoonotic pathogens, including rabies, severe acute respiratory syndrome (SARS), Henipavirus (i.e. Nipah virus and Hendra virus) and possibly ebola virus. Their high mobility, broad distribution, and social behaviour (communal roosting and fission-fusion social structure) make bats favourable hosts and vectors of disease. Many species also appear to have a high tolerance for harbouring pathogens and often do not develop disease while infected. However, contrary to folklore, this is not true of rabies, which is as fatal to bats as it is to all other species. However, a bat may be ill with rabies for a longer time than other mammals.

In regions where rabies is endemic, only 0.5% of bats carry the disease. In the United States, bats typically constitute around a quarter of reported cases of rabies in wild animals. However, their bites account for the vast majority of cases of rabies in humans. Of the 36 cases of domestically-acquired rabies recorded in the country in 1995-2010, two were caused by dog bites and four patients were infected by receiving transplants from an organ donor who had previously died of rabies. All other cases were caused by bat bites. Rabies is considered fully preventable if the patient is administered a vaccine prior to the onset of symptoms. However, unlike raccoon or skunk bites, bat bites may go ignored or unnoticed and hence untreated. Rabid bats are broadly distributed throughout the United States; in 2008-2010, cases were reported in every state except Alaska and Hawaii, and Puerto Rico.

Rabid bats may be clumsy, disoriented, and unable to fly, which makes it more likely they will come into contact with humans. One should avoid handling them or having them in one's living space, as with any wild animal. If a bat is found in living quarters near a child, mentally handicapped person, intoxicated person, sleeping person, or pet, living in an area where rabies is known to occur, the person or pet should receive immediate medical attention for rabies. Bats have very small teeth and can bite a sleeping person without being felt. There is evidence that it is possible for the bat rabies virus to infect victims purely through airborne transmission, without direct physical contact of the victim with the bat itself.

If a bat is found in a house and the possibility of exposure cannot be ruled out, the bat should be sequestered and an animal control officer called immediately, so the bat can be analysed. This also applies if the bat is found dead. If it is certain nobody has been exposed to the bat, it should be removed from the house. The best way to do this with live bats is to close all the doors and windows to the room except one that opens to the outside. The bat should soon leave.

Due to the risk of rabies and to health problems related to their faecal droppings, bats should be excluded from inhabited parts of houses. The Centers for Disease Control and Prevention (CDC) provide fullly detailed information on all aspects of bat management, including how to capture a bat, what to do in case of exposure, and how to bat-proof a house humanely. In certain countries, such as the United Kingdom, it is illegal to handle bats without a license.

Where rabies is not endemic, as throughout most of Western Europe, small bats can be considered harmless. Larger bats can give a nasty bite.

Mythology

In European cultures, bats have long been associated with witchcraft, black magic and darkness. The witches incorporate bat in their brew in Shakespeare's Macbeth. Because bats are mammals, yet can fly, this gives them status as liminal beings in many cultural traditions.

The bat is sacred in Tonga and is often considered the physical manifestation of a separable soul. Bats are closely associated with vampires, who are said to be able to shapeshift into bats, fog, or wolves. Bats are also symbols of ghosts, death, and disease. Among some Native Americans, such as the Creek, Cherokee and Apache, the bat is a trickster spirit.

Chinese lore claims the bat is a symbol of longevity and happiness, and is similarly lucky in Poland and geographical Macedonia and among the Kwakiutl and Arabs.

Pre-Columbian cultures associated animals with gods, and often displayed them in art. The Moche people depicted bats in their ceramics.

In Western culture, the bat is often a symbol of the night and its foreboding nature. The bat is a primary animal associated with fictional characters of the night, both villains, such as Dracula, and heroes, such as Batman. The association of the fear of the night with the animal was treated as a literary challenge by Kenneth Oppel, who created a best-selling series of novels, beginning with Silverwing, which feature bats as the central heroic figures much as anthropomorphized rabbits were the central figures to the classic novel Watership Down.

An old wives' tale has it that bats will entangle themselves in people's hair. One likely source of this belief is that insect-eating bats seeking prey may dive erratically toward people, who attract mosquitoes and gnats, leading the squeamish to believe the bats are trying to get in their hair.

Mesoamerica

In Mesoamerican mythology during the Classic-Contemporary period, bats symbolized the land of the dead, which was considered to be the underworld. They also symbolized destruction and decay. Bats may have symbolized in this way because they fly only at night and dwell in caves during the daytime and are associated with human skulls and bones by classic Maya ceramists. Central Mexicans sometimes depicted bats having snouts that looked like "sacrificial knives and carrying human head" in the Postclassic era. Bat images were engraved onto funerary urns, and were emphasized with large claws and round ears by Zapotecs. They were commonly associated with death. The depiction of bats on funeral urns and goods took on some the characteristics of the jaguar, which was, and still is, another entity of the night and the underworld. There have also been instances where bats are portrayed next to other animals portrayed negatively in Mesoamerica, including scorpions and other nocturnal animals such as owls.

A gigantic, life-size, ceramic bat-man has been discovered and dug up from the Templo Mayor. The Templo Mayor is located in the centre of the Mexica capital of Tenochtitlan. Known as a god of death, this statue has the clawed feet and hands of a bat, but the body of a man. The statue's human-like eyes bulged out from the bat-like head, making the Zapotec images very realistic and living. In the 1930s, the Kaqchikel Maya were said to have proclaimed the bat was the Devil’s provider. Kaqchikel would leave the Devil’s underworld home and collect blood from the animals to be used for scrumptious meals to feed the Devil. “In the myths, the beast of prey and the animal that is preyed upon play two significant roles. They represent two aspects of life—the aggressive, killing, conquering, creating aspect of life, and the one that is the matter or, you might say, the subject matter”. In the Devil’s underworld, dead sinners would work off their sins to get to heaven, indicating the bat, too, was a sinner and worked under the authority of the Devil.

Oaxaca

According to Oaxacan mythology, the bat's nocturnal nature can be traced back to its ancient jealousy of birds' feathers. One day, as the myth goes, the bat felt isolated and undesirable, and told God that he was cold. God, fair and just, turned to birds in the animal kingdom and asked if they would show compassion and donate a feather to the bat to help him keep warm. The birds all agreed and began to pluck one feather from their bodies to give to the bat. With all of these feathers, the bat became even more magnificent-looking than all birds, and was able to spread colour to the night sky. During daylight the bat created rainbows that reflected vibrant colors from the sun. With his new beauty and abilities, the bat soon became arrogant and conceited. The birds grew tired of the bat’s self-glorification and decided to fly up to heaven and ask God to do something. When the birds told God of the bat's behaviour, He was surprised and decided to take a look Himself. When on earth, God called on the bat to show him what he was doing. The bat began to fly across the light blue sky where, one by one, each feather began to fall out, uncovering the bat’s natural, ugly-looking body. When all his feathers were gone, the bat became distressed and ashamed of his appearance. He decided to hide in caves during the day and only come out during the night to search for his long-lost feathers.

East Nigeria

According to a particular East Nigerian tale, the bat developed its nocturnal habits after causing the death of his partner the bush-rat. The bat and the bush-rat would share activities such as rummaging through the grass and trees, hunting, talking and bonding during the day. When at night, the bat and the bush-rat would alternate in cooking duties, cooking what was caught, and eat together. It appeared to be a dedicated partnership, but the bat hated the bush-rat immensely. The bush-rat always found the bat’s soup more appetising, so when eating dinner one night, asked the bat why the soup tasted better than his own and also asked how it was made. The bat agreed to show him how to make it the next day, but instead was forming a malicious plan.

Next day as bat prepared his soup, the bush-rat came, greeting him and asking if he could be shown what was agreed yesterday. Earlier, the bat has found a pot looking exactly like the one he used usually, but it held warm water and so decided to use this instead. The bat explained to the bush-rat that to make his soup, he had to boil himself prior to serving the soup, where sweetness and flavor of the soup came from the flesh. The bat jumped in the pot seemingly excited, with the bush-rat mesmerised. After a few minutes the bat climbed out and while the bush-rat was distracted, switched pots. The bat then served his soup out of the soup pot, both tasted it. Overanxious and eager, the bush-rat jumped into the pot of warm water. He stayed much longer in the pot, dying in the process.

When the bush-rat’s wife returned that night to find her husband dead, she wept and ran to the chief of the land's house, telling him about what happened and what she was sure what the bat had done. In hearing this, the chief became angry, ordering for the immediate arrest of the bat. It just so happened that the bat was flying over the house and overheard what was just said. He quickly went into hiding high up in a tree. When the chief’s men went looking for the bat, he could not be found. The search to arrest the bat carried on over several days, but he still could not be found. The bat needed to eat, so flew out of hiding every night to hunt for food to escape of being arrested. This, according to Eastern Nigeria mythology, is why bats only fly at night.

Heraldry

The bat is sometimes used as a heraldic symbol. The coats of arms of certain cities in eastern Spain, such as Valencia, Palma de Mallorca and Fraga, have the bat over the shield. Formerly, the Barcelona city coat of arms also had a bat crowning it, but the bat has been removed in the present-day versions.

The heraldic use of the bat in Valencia, Catalonia and the Balearic Islands has its origins in a winged dragon ( vibra or vibria), which featured in King James I of Aragon's helmet or cimera reial. This is the most widely accepted theory, although there is also a legend that says that due to the intervention of a bat, King James was able to win a crucial battle against the Saracens that allowed him to win Valencia for his kingdom.

The use of the bat as a heraldic symbol is prevalent in the territories of the former Crown of Aragon and it is little used elsewhere. However, it can be found in a few places, as in the coats of arms of the city of Albacete, in Spain, as well as the town of Montchauvet (Yvelines), in France.

Certain Spanish football clubs including Valencia CF and Levante UD use bats in their badges.

The Burgee of the Royal Valencia Yacht Club (Reial Club Nàutic de València) displays a bat on a golden field in its centre.

State symbols

Three U.S. states have an official state bat. Texas and Oklahoma are represented by the Mexican free-tailed bat; Virginia is represented by the Virginia big-eared bat.