Bats are one of the most successful and diverse of all mammals. There are nearly 1,000 species known. Since there are about 4,450 species of mammals, this indicates that 22% of all the mammals across the globe are bats. Out of the 21 orders of mammals in the world, only Rodents with about 1,820 species are more diverse in comparison.
Bats range from small to medium in size and can be immediately recognized since they have wings which makes them capable of flight. They have a knee directed backward due to the rotation of the hind-limb. They give birth to live young and usually have complicated social lives. Contrary to popular belief which has might have caused you to think of them as dirty, scientific studies have shown that like all mammals, bats routinely groom themselves and are overall clean animals.
Due to some strange reason a lot of people seem to be afraid of bats. There is no solid evidence behind this since bats are harmless creatures. Also, despite the common superstition, they are very unlikely to get caught in somebody’s hair. Like most of the animals, if you tend to mistreat them they sure will bite in defense, however, if left unbothered they pose no such threat to humans. The dreaded vampire bat is said to be dangerous only because of the fact that it is highly likely to act as a vector for a number of diseases. However, the amount of blood it drinks is even less than the amount you might lose from a minor wound.
Bats might not be dangerous to mankind, however, mankind is dangerous to bats. A sharp decline has been observed in most of the bat populations over the last 50 years, the main reason being the modern agricultural policies along with increased hunting. A number of bat species are now endangered.
Classification of Bats
Taxonomically, bats constitute order Chiroptera, the meaning of which is ‘hand-winged’. The order is further divided into two suborders; the Megachiroptera and the Microchiroptera. Although scientists suggested in the past that both the suborders might have evolved separately, they have now come to an agreement that they are monophyletic, i.e. all bat species evolved from a single ancestral heritage.
The Megachiroptera are the fruit and blossom bats, they are generally larger than the Microchiroptera and are commonly found in Africa, Indochina, East Indies, and north and east of Australia. They are not typically found in the United States. The Megachiroptera comprise of a single family of about 180 to 190 species. They have long faces, especially the ones that feast on nectar, along with large eyes which makes them look a bit like foxes. This is the reason why most of them are given the common name of Flying Fox. A number of species lack the ability of echolocation and depend upon smell and sight to find their way around.
The Microchiropterans are known as the True Bats and are smaller in size. The largest members of the Microchiropterans are quite a bit bigger as compared to the smallest of the Megachiropterans. The largest species of the Microchiropterans weigh about 160 grams, whereas the average body mass of Megachiroptera species is nearly 200 grams. Most Microchiropterans species, in comparison, weigh less than 30 grams.
Over 1,100 different species of bats have been identified all across the globe. This is approximately 20% of all of the mammals on the planet. Following are a few commonly found bats:
The Fruit Bat falls into the class of Megachiroptera and is known as Flying Foxes in some areas. They vary greatly in their size from one location to the other.
The Indiana bat is a medium-sized mammal. It can range in color from brown, black, or grey. They range in size from one to two inches in length when fully grown. Their weight is about a quarter of an ounce.
The Vampire Bat is an amazing creature and one that has been a part of legends and folklore for centuries. This certain species of bat possesses a short muzzle that is the shape of a cone.
Egyptian Fruit Bat
The Egyptian Fruit Bat is a smaller species of bat varying in length from about six to eight inches. However, they have a huge wingspan of about two feet. They weigh less than half a pound.
Little Brown Bat
The Little Brown Bat species is very well known across the globe. It is extremely small with an overall body size varying from 3 to 3 ½ inches. They also weigh nearly half an ounce.
Giant Golden-Crowned Flying-Fox
The Giant Golden-Crowned Flying-Fox Bat is a very rare species and one that possesses very long wings. They are so large in size that they often wrap them around their body like a cloak.
Kitti’s Hog-Nosed Bat or Bumblebee Bat
The Kitti’s Hog-Nosed Bat is a species that has a very unique look to it. The reason why it is also known as the Bumblebee Bat is because of its extremely small size.
Bat Species in Florida
Florida serves as a home to thirteen different species of bats that live there either all year round or for specific seasons. All thirteen types feed on insects. Some live in large colonies while some roost alone. There are seven other bat species that have been occasionally found in Florida but are not known to normally reside here. These are called the accidental species. Three of them belong to the cold northern regions whereas four are from more tropical areas. Those from the colder regions feed on insects while the tropical ones are known to eat fruits and nectar. The latter is specifically found in south Florida and the Florida Keys. Following are the 13 different species:
- Big brown bat
- Tricolored bat (Eastern pipistrelle)
- Evening bat
- Gray myotis
- Northern yellow bat
- Seminole bat
- Velvety free-tailed bat
- Brazilian free-tailed bat
- Eastern red bat
- Florida bonneted bat
- Hoary bat
- Rafinesque’s big-eared bat
- Southeastern myotis
- Accidental species
Bat Distribution and Habitat
The bat is a mammal that is highly adaptable. Research reveals that there are very few regions in the world where they are not present. They normally live inside caves where they have easy access to water, a safe place to hide from enemies during the daytime, and an abundance of food. They often live in large colonies and it is very rare that you’d find just a small number of them in a particular location.
Abandoned, ancient mine shafts can also sometimes provide a suitable environment for bats to colonize. Another common location for bats to be found is under the bridges. This provides them with the best suitable environment that even gives them protection from predators. An additional benefit is that they don’t have to worry much about too much disturbance from humans at such locations either. They are known to roost under huge trees having full branches and leaves in many areas. Such trees help them remain camouflaged from a number of predators.
Such a type of environment can prove to be a problem as well. For instance, when bats begin occupying trees in public parks or wildlife locations. Humans often make use of such locations for bird watching, camping, star gazing, and a number of outdoor events such as wedding ceremonies and concerts.
Bats can also be found in other safe and dark structures as well. For example, they can be seen occupying your chimney, the attic, and even old abandoned buildings. As long as the habitat has its safety factor in place, more and more bat populations will be attracted to it. During nighttime they tend to fly out in different directions, however, they will continue to come back to that undisturbed colony when they wish to rest.
Bats are known to typically roost at the exact same location in that particular colony when they come back to rest. They do make some changes in the structural framework from time to time. For instance, when females are pregnant they make certain maternity areas in the colony. They will huddle close with each other in order to remain warm. Once they give birth to their young, they will huddle so that they could protect their offspring from predators as well as harsh weather conditions.
Many people ponder upon the fact that why bats hang upside down. The reason for this behavior is that it helps them hide from predators with greater ease. It even makes it possible for them to take off in flight. They are unable to run with their legs to take off like birds do since their legs are too small for that.
During the winter season, a number of bat species migrate so that they could hibernate. They move in search of a safe, protected place where they could rest with ease. During this time, their body rate slows down for about six months. The locations they choose to hibernate include mines, caves, and abandoned buildings. They will no longer reside in open areas like trees or under a bridge otherwise their bodies will get too cold.
These colonies can be extremely large for hibernation so that they could huddle close to each other. The greater in number they are, the warmer they can remain during the harsh winters.
Such close proximity of the bat habitat is known to be associated more with survival than with their need for socializing. Thus if you disturb a colony of bats then be ready for them to emerge in large numbers.
Since the echolocation abilities of bats are disturbed when they fly in the rain, you will seldom observe them doing so. They tend to wait for the rainfall to end before going out in search of food. Under certain circumstances, however, they might need to go out in the rain, which can lower their chances of successfully finding sufficient food to eat.
The Reproduction System of Bats
Since bats often live in very large colonies, it isn’t difficult for them to find a partner to mate. However, the females and male members of the colony normally remain segregated unless it is time to mate. Once the females are pregnant, about a hundred or so of them would form a maternity colony which is a sub-area of the main colony.
The breeding season for this flying mammal is in the spring season when temperatures begin getting warmer. This also tends to be the time of the year when they can easily find most of the food supplies. Although they normally have only one breeding season, it may be possible for a female bat to have two or even three litters during that time period. Regardless, only one young will be born at a time.
Caring for her young can be a very difficult process for the female bat. She has to keep flying in search of food even while she is pregnant. The offspring drinks milk from the mammary glands of the mother’s body. When born, the young don’t have fully developed wings. Once their wings develop, they will become capable to start hunting for their own food. When their wings get completely developed, it isn’t long before they move out on their own.
While females do take time to properly look after their young ones, they don’t get that time with them. The young ones can be fully independent of six weeks to four months of age, depending upon their species. This is the reason why a number of bat species are successfully able to reproduce a number of times in a given mating season.
When the young are being looked after, they normally hang from the soft, furry belly area of their mother. This is where they eat and sleep. Also, the heat from the mother’s body allows them to remain warm. It is a common behavior for a number of these mothers and their offspring to huddle up in order to keep each other warm enough.
Experts are amazed by the bat reproduction process. The female is extremely intelligent regarding manipulating the time for her pregnancy and the birth of the offspring. This normally happens when food is in abundance. It is also going to happen during the season when the remaining environmental factors are most suitable.
Since these factors can vary in different environments where bats live, observing these behaviors can be very interesting. Such control from the mother’s side gives their progeny optimal chances of ultimately surviving and becoming mature. In order to attain such control, nature has given such an ability to the female that it can delay the fertilization process of her eggs.
Keeping that in mind, it is highly likely for the actual mating process to occur in the fall. However, the female would not release the sperm to fertilize with her eggs until a certain time in the spring season. For other mammalian species though, the actual mating and the fertilization process both occur at the same time.
Regardless of all of this, the bat is considered to be one of the slowest reproducing animals on the planet. This the reason why the situation gets alarming when large populations of them get killed due to humans destroying their natural habitat. Large numbers of them are also being wiped out due to the White-nose syndrome, which is a disease-causing fungus.
Under suitable conditions, bats are known to live for about twenty years in the wild. Some bat species tend to have a longer life span than the others.
Echolocation and Bats
A number of bat species depend upon echolocation to help them find food. This is the reason why they have no difficulty at all to find their prey even in complete darkness. The calls from bats can reach up to 130 decibels. These are known to be the most intense of all the airborne animals on the planet.
The phenomenon of echolocation is rather complex, the various aspects of which have been thoroughly studied by various scientists. What is observed is that they have the ability to identify the different signals coming in and going back out. This is how they can effectively send signals as well as receive them. One can think of the process like what happens when you are in an empty room or a cave and your own voice echoes back to you.
The process of echolocation has been divided by researchers into two categories; high duty cycle echolocation and low duty cycle echolocation. The low duty cycle is used by bats with short calls. This enables them to finish making their own calls before they get to receive signals. The bat tends to contract the muscles of its middle ear as they call so that they don’t harm their eardrums with their own calls.
When bats relax their middle ear muscles, they are able to hear returned echoes. This difference is what they utilize to estimate the location of their prey along with its distance.
When it comes to the high duty cycle, a continuous release from the bat is observed in terms of calling. They get an echo back with a different frequency which tends to occur when they are in flight.
The great deal of information that we know about echolocation in bats is credited to Lazzaro Spallanzani. He conducted a number of tests in the late 1900s which involved putting various bat species in darkness. Even without light, they were able to successfully move around looking for food. However, when Lazzaro plugged their ears, they experienced difficulty moving around and locating their food sources. This study proved that the bats were depending upon their ears rather than their eyes for movement.
The clicking behavior of bats is also linked with echolocation. These clicks have a particular meaning in a manner similar to the Morse Code. Bat detectors have been very useful in a number of studies in order to determine various frequencies and to gather information regarding how echolocation is utilized by various bat species.
Researchers are still unable to understand what the entirety of communication between bats means. The reason being that the pitch of their sounds is usually so high that it is out of the normal hearing range of humans. The intensity and frequency of these echoes are used to determine at what distance are food or other colonies of bats located.
Since some bat species have poor vision, echolocation is typically used in conjunction with their sense of sight. Paleontologists have proved that ancient fossil remains of bats show that echolocation was something that they were unable to do nearly 52 million years ago. Therefore this process is believed to be evolved especially for bats as a survival and defense mechanism.
As technological advancements continue to progress, researchers are hopeful that bat echolocation can be studied even further with added depth. Improvement in data collection, as well as interpretation methods, is a part of the current efforts that a number of scientists are involved with. They are struggling to find out exactly when and how the concept of echolocation came into being through the evolutionary process.
However, for that to be determined a lot more bat fossils need to be discovered. Some fossils were found a few years ago therefore scientists are hopeful that more will be found in the future.
Role of Bats in Pollination
When we talk about pollination, it is usually the bees and the birds that we think of. A number of people have no idea that the bat species also play a significant role in this process. This process occurs on a large scale around the globe. Some regions do rely on pollination by bat species more than the others. These include Asia, Africa, and the Pacific Islands.
Bats help with the pollination of a number of different types of fruit in the world. These include mangoes, bananas, and peaches. It is believed that nearly 500 various types of tropical plants are successfully pollinated each year through bats. Bats are able to fly large distances before they drop off seeds, this helps maintain great diversity in the areas of growth.
Bats are particularly attracted to flowers that don’t have a strong scent and are of dull, light colors; quite the opposite of what attracts birds and bees. The types of flowers that bats are attracted to seem to produce lots of nectar. Experts even believe that the bees and birds take the day shift whereas the bats take the night shift pollinating different plants.
Bats, unlike birds, don’t have a long beak to procure nectar but are still able to pollinate. This is because they have a very long tongue. When it is not being used by the bat, this tongue is rolled up inside the body’s rights underneath the rib cage. While using it, they have complete control over their movement.
Since many bats are typically migratory in nature, they can efficiently carry out the pollination process at great distances. This behavior introduces new plant species to various habits. Sometimes they grow there successfully. In short, bats play a key role in the overall pollination process across the globe.
Tequila is derived from the agave plants. The Mexican Long Tongued Bat plays a significant role in the spread of its seeds so that these plants can successfully grow in diverse regions.
The fact that bat species contribute this much towards pollination is one of the main reasons why their populations are conserved in many areas. Scientists realize that if bats cease to exist at certain locations it will have a drastic impact on the growth and development of a number of plants, fruits, and flower species.
Bats are also known to keep insects, pests, and bugs away from crops. They consume tons of them every year which would have otherwise destroyed important cash crops. Some of the pests they feed on include Stink Bugs, June Beetles and Corn Worm Moths. Without bats, we would have to use chemical pesticides to control these insects.
Bats and Coronavirus
It is a fact that some of the worst viral disease outbreaks seen by mankind in recent years; SARS, Ebola MERS, Marburg and possibly the novel coronavirus have originated from bats.
A new study conducted by researchers in the University of California concludes that the fierce immune response of bats to various viruses could cause viruses to replicate much faster, so that when they get transferred to mammals with a weak or average immune system, such as humans, then these viruses wreak havoc.
This is what makes bats an extraordinary reservoir of quickly reproducing and highly contagious viruses. The organism itself can tolerate a variety of such disease-causing viruses. However, when these bat viruses get transferred into hosts with a slow-response immune system, these viruses rapidly overpower their host’s organ systems, resulting in death or disability.
Researchers have also found out that disturbing the habitat of bat colonies creates an environment of stress for the animals which causes it to shed even more virus in their urine, saliva, and feces that infects other animals.