Did you know that bats are the only mammals in the world that can fly? That's right, these animals, although they are flying, also belong to the mammalia class. They are also called bats. For many years, wrong myths have been created about these animals, however, we must know that they are very important.
Let's know a little about bats
Like all other mammals, bats gestate within the female's placenta. Although these animals have 4 limbs, two of them develop as wings, which is why they can fly without any problem.
Bats are the second species of mammals with the most diversity and population, since they currently have approximately 1.100 species, which means that they occupy more or less 20% of the total population of mammals on Earth. Nowadays, bats can be found in almost every country in the world, however, we must except Antarctica and places where the cold is very strong.
The bat is the only mammal in the world that is capable of flying, which is why it is considered a cosmopolitan species, thus occupying a large part of the most important ecosystems in the world. Many are unaware of the importance of these animals within the ecological system, bats are pollinators, they have the ability to keep excess pests at bay and, in addition, they are very important for the distribution and expiation of various seeds, especially fruit. .
These Flying animals They have the incredible ability to be able to orient themselves at night through the echolocation system. When they fly at night, they are not guided by sight as many might think, in fact, it is echolocation that tells them if they are close to some object, and even some food.
More than half of the bats feed only on insects, while the rest of them have a fruit-based diet. However, we must bear in mind that a very small part of this animal species also feed on other animals, whether they are small reptiles, rodents, fish and even other bats.
We cannot forget the vampire bats, this subspecies receives its name due to the unique similarity it has with its mythological namesakes, as these also feed on blood. Although there are two other subspecies that share these characteristics.
The size of these animals will vary depending on the species to which they belong. A clear example is that of the botfly bat, which measures no more than 35 millimeters and its meso does not exceed 2 grams. While what, there is the Philippine flying fox, a kind of giant bat that can measure more than a meter and a half with its wings spread, while its weight exceeds a kilogram.
Due to the nocturnal habits of most bat species, these animals have been classified as undesirable nocturnal beings, since a large number of myths and erroneous beliefs have been created about them that cause great uncertainty and panic in people.
In addition to that, the multiple appearances of these animals in the cinema, cataloging them as annoying, evil and even bloodthirsty animals, has only increased these fears. However, we must be clear that there are only 3 species of these animals that, like the mythological vampire, feed on blood, and no, they are not dangerous at all for humans.
For a long time and even today, in China, bats are considered a sign of good fortune and happiness, because for this culture, they are always beneficial since they have eradicated large pests that attacked their crops and also help to the pollination and expansion of seeds that, over time, will bring much more abundance in flowers and fruits.
bat morphology
There are very few Vertebrate animals that are capable of being able to fly through the skies, among these are birds, pterosaurs (flying species from the age of the dinosaurs) and bats. In order to achieve this, these animals have modified their bodies until their front limbs are much longer. The fingers of these animals, with the exception of their thumbs, are extremely long, in addition, between them, there is a thin membrane of skin called patagium, which allows them to stay in flight.
The coat of bats will vary depending on the species, however, in general, the tones will be in shades of brown, reddish, yellowish, gray and black. As we said before, the size will also depend on the species, currently the smallest mammal in the world is the botfly bat, which has an approximate size between 29 and 33 millimeters. However, there are other much larger bats, such as the Philippine flying fox, Indian flying fox, Livingston's flying fox or the great flying fox.
Bats have a very particular bone structure, because, unlike other mammals, bats have very unique lower extremities, since the hip is joined with a 90º turn, this means that their hind legs are projected forwards. the sides. If we see an image of the skeleton of these animals, we can notice that their knees are almost inverse to those of other mammals.
The arrangement of their lower extremities makes the walk of these mammals a bit unique and clumsy if we compare it with the rest of the four-legged animals. The way these limbs are positioned helps bats have that incredible ability to remain upside down for a long period of time.
In addition to all of the above, bats have thumbs on their hind legs that have a claw which they use as an aid to stay hanging and climb different surfaces. When these mammals are upside down and hanging, the weight of their bodies causes their tendons to contract, in this way, their nails are in a way that allows them to remain hooked even if they are sleeping, in this way they do not have the need to expend energy even when they spend many hours in that inverted position.
Skeleton
The skeleton of bats is very special and different from the rest of the mammals, since they have an elongation of the limbs that the others do not have. A clear example is the elongation of the fingers of the upper extremities, which are almost the total length of its entire body, and even a little more. In addition to the fingers, it can be seen how several of the bones that make up the arms and legs of these animals have been lengthened and modified in such a way that they benefit them while they fly or are held upside down.
As the movement that is exerted at the time of flight falls especially on the shoulders of the bat, the humerus of its arms is much longer than normal and has a much more prominent head, while it is unique to the bat. scapula in a rather particular way. The elbow of these animals is not used for anything other than stretching or flexing the arm.
Head
The shape of the bat's head can be different depending on the species we are referring to. Although many of these mammals have heads very similar to those of rodents, they also have some structures specially designed for bats and that makes them special. Most bats have some structure on their face that helps make the ultrasound they emit much more powerful and precise.
In general, the ears of these animals are large, which makes them very conspicuous. In addition to their large size, they have a kind of groove inside them and a fairly large lobe with a lot of skin that helps them have a greater hearing capacity for echolocation that characterizes this species.
According to studies carried out on these animals, it is said that microchiropterans can only see in black and white, while macrochiropterans can see in color. Although it is true that microchiropterans have small and not very well developed eyes, the reality is that they are not blind, in fact, they use their sight to be able to visualize at those distances where echolocation does not reach.
At present, several studies have been carried out on this species of chiropterans where it has been known that these animals are capable of seeing the ultraviolet light that some species of flowers have, this would be what helps these animals find the flowers they they possess the nectar with which they feed.
Some others are said to have a sixth sense, that of magnetoreception, that is, they can orient themselves through the magnetism of the Earth, something widely used by other animals, such as birds when they migrate. This magnetoreception helps bats to orient themselves when they are flying at night.
On the other hand, the macro chiropterans have a much clearer vision than that of the micro chiropterans, this is because they do not have the echolocation system. That is why their vision is much more developed, in addition to this, they are also able to use their sense of smell together with their sight to be able to find their food.
In general, bats have teeth made up of around 32 and 38 teeth, of which the canines stand out, these are created in a special way that makes them stand out from the rest. The adaptation that this species of animals has had to undergo and the diverse forms of feeding that they possess, have made them one of the species of mammals with the most configurations in their teeth, since at least 50 formulas of them are known.
The species of bat that is known and that has fewer teeth is the common vampire bat, since they only have 20 teeth. Now, we can say that microchiropterans have teeth very similar to those of other animals that base their diet on insects, since mimes are extremely sharp and sharp, capable of penetrating the thick and hard skin of the various insects. insects that eat or the skins of some fruits.
Meanwhile, the teeth of the macro chiropterans are specially designed to be able to penetrate the hard skins of the various fruit groups that they consume. Another of the species, especially speaking of pollinators, has a fairly long tongue, the longest of mammals. With this long and narrow musculature, these animals manage to reach the deepest part of some flowers to be able to feed through their conical-shaped receptacle. When they retract their tongue, it is coiled inside the animal's rib cage.
Alas
Bats are the exact example of the various possibilities that mammals have to be able to develop their limbs a priori to be able to survive in an environment that does not favor them. Well, these animals have managed to make all the fingers of their extremities, with the exception of the thumb, lengthen in such a way that the skin membrane or patagium can be adequately supported and that, in this way, they can take flight.
This skin membrane is nourished by various blood vessels, nerves and muscle fibers that allow the animal to have control over them when flying and being on the ground.
The patagium is divided into different forms:
- Propagation: This goes from the neck of the animal to the first finger of the same.
- Fingerprinting: it's the one between each of the bat's toes.
- Plagiopathy: this is located between the last toe and the hind legs of the animal.
- Uropatagium: This is the membrane that joins both lower extremities to each other, including all or part of its tail. The size of it will depend on the species of bat. Some species do not even have it.
Bats lack calcium in the fingers of their body, this makes them especially flexible, which is why they can be twisted and moved in such a way that it would be impossible if they were calcified, since they would break. In addition to this, they, unlike those of other animals, are flattened instead of circular, which makes them even more flexible than they usually should be. The membrane between the toes of bats is much more elastic than the skin of any other mammal.
Bat wings are much thinner than bird wings in general, which is why bats can fly much more effectively and with greater mobility than any other flier. However, this thinness in the skin makes it much more fragile and tends to be much easier to tear than that of any bird. However, the advantage that bats have is that it can regenerate quickly, so it does not represent a great inconvenience for these animals.
In addition to enabling them to fly, the wings of bats serve as a means of protection for their body, this is because they serve as a kind of thermal regulator that helps them maintain heat when the animal is at rest. In this way, the cold weather does not affect them too much.
Contrary to this benefit, they also fulfill the task of being able to cool the animal's body while it flies, since the blood that circulates through the wings cools with their movement, making this help their body regulate itself. thermally.
How is the echolocation of bats?
In the year 1793, the researcher Lazzaro Spallanzani, while investigating the way in which bats hunted and flew, discovered that they could not maintain their concentration when they could not hear, however, even when they could not see, they were able to be able to avoid objects and reach its prey.
It was not until 1920 that another researcher began to propose the idea that bats could orient themselves and capture their prey using their sense of hearing as a locator. But it was finally in 1938 when Donald Griffin, by means of what were now new high-frequency microphones, managed to record that bats were capable of emitting ultrasound.
Just as the sperm whales and the Dolphin, bats are able to use echolocation. This is a system capable of using sound to create waves that, when they return to the emitter, go to their brain through the auditory nervous system which allows them to orient themselves, know if they have an obstacle in front of them, find their prey or simply, to be able to communicate with their kind. This system could be compared to the sonar used by ships but it is totally biological.
Micro chiropterans manage to make these sounds thanks to the contraction of their larynx, which should be noted, are much wider than those of other mammals. These sounds can be very varied, that is, they will not always have the same frequency or the same duration, their intensity and the rhythm that they emit at the moment of being transmitted, can also be different for each time of environment or situation that occurs. the animal requires.
These ultrasounds are emitted through the bat's mouth or nose, but it is the nasal plates that are responsible for giving them the necessary amplification. The frequency of each species is going to be very different, because it is something that differentiates each one of them.
Human beings are only able to perceive up to 20 kHz, however, bats can emit from 15 kHz to 200 kHz, which is why it is not uncommon for humans to be unable to hear them. There are two types of frequencies used by bats, the constant ones, which do not vary while the signal is transmitted, and the modulated ones, which will go from the highest intensity to the lowest.
The sound emitted by the bat can be silent suddenly or gradually, that is, they will go off as time goes by until it turns off completely, this will depend, again, on the species of the animal.
The vast majority of microchiropterans stop emitting echolocation sounds when they are in places that are already known by heart and that are easy for them to navigate without using sound, since it is believed that, in this way, , they prevent their predators from knowing where they are and thus manage to safeguard their lives.
The mega chiropterans, which have a diet based on fruits, nectar and pollen, do not have this echolocation system, since the mimes depend solely on their sight to be able to guide themselves either in their environment or to be able to reach their food.
bat feeding
The feeding of bats can be very varied, just like all other mammals, these animals can have a quite diverse diet. Generally, the diet of these animals is largely responsible for the physical, morphological and ecological differences that can be observed in all these animals and in their diversity of species. They can feed on insects, fruits, pollen, flowers, blood, and can even become scavengers and eat some of their own species or other mammals.
The types of ditas will depend on the two orders of bats that exist:
- Mega Bats: These animals usually feed on fruits, pollen and the nectar of flowers, however, in some given moments, they could also feed on carrion or eat some types of small birds or fish.
- Micro chiropterans: In this order there is a great variety of diets, there are those that feed on insects, which also, like the mega chiroptera, eat fruits, pollen or nectar, which eat carrion, birds, fish, reptiles, other bats and even those that feed on blood.
Let's learn a little about the types of bats according to the feeding of these animals:
insectivores
The vast majority of bats belong to this group, that is, they feed only on insects. Thanks to the great availability, variety and abundance of insects, this is one of the easiest foods to obtain, so it greatly benefits them.
Thanks to the fact that bats have a nocturnal habit, these animals do not have great competition during their hunts, since most of the birds that share their diet are asleep at that time. They do not despise any type of insects, so the vast majority of them are welcome as food. In some cases, although not very often, bats can also feed on spiders, scorpions, centipedes or even the odd crustacean.
Most insectivorous bats are small in size, in addition to that, they hunt their prey while they are in flight, so they do not need to stop to capture them. Some of these animals use their own wings or legs to capture their prey, although some others have a membrane on their hind legs that helps them catch it, this membrane sometimes has a shape like a bag, where the insects it hunts are trapped.
frugivores and polynivores
There is an approximate 25% of bats that are vegetarian, that is, they do not need to feed on any other animal and only consume fruits or pollen. These species can be found mainly in the tropical and equatorial areas of our Earth. In general, their food is based solely on fruits or the nectar of flowers, however, there are some cases where mimes can also eat leaves, although this is not very common.
These animals prefer to eat those fruits that are sweet or have a large amount of pulp or meat, however, they avoid the consumption of those fruits with strong odors or excessively bright colors. These bats take the fruit with their teeth and literally rip it from the trees that contain it.
Once they have ripped it out, they fly with it in their mouths until they settle in a quiet place where they will begin to ingest it. These animals eat until they are satisfied, so the surplus of the same fruit or its seeds end up in the ground under them, in this way, they begin a new cycle of growth where they will begin germinating and taking root until one day they grow and can provide their own fruits.
carnivores and piscivores
There are very few species of bats considered completely carnivorous. In this specific case, we determine carnivores, those bats that feed on other small vertebrates, except fish, and that they are a fundamental part of their daily diet. However, it seems that there are some species that are essentially carnivorous or that do so for occasional reasons, that is, they use this feeding method when they need it, while there are others that do it opportunistically, which means that they , if they get a prey, they take advantage of it or steal it if necessary.
In some cases, we can find some species of bats that we could call piscivores, that is, they feed on fish, although as with carnivores, the vast majority of them do not have a diet that is specifically based on food intake. Of fishes.
Hematophages
Although many people, even today, still think that bats are blood-sucking animals, the reality is that there are only 3 species of these animals that actually feed on blood, these animals are known as hematophagous. These three species of bats are located within the American continent. Since the existence of these animals was known, the mimes were baptized with the name of vampires, referring to those mythological beings so feared that they feed on human blood.
The three species of vampire bats are:
- Common Vampire: which is that it has more specimens today; This animal feeds especially on the blood of farm cattle, although it can also feed on small domestic animals such as dogs, toads, tapirs, guanacos and also seals if they are within its reach.
- Hairy-legged vampire: this species of bats is much smaller than the previous one; it feeds on the blood of the birds that are in its ecosystem.
- White Winged Vampire: Of the three species of vampires, this is the least known and the one with the fewest specimens. It also feeds on birds. Very little is known about this species, the little information that has been collected has been from those specimens that have been found inside some chicken coops.
When night falls, these animals go out in pairs or in small groups of up to 6 specimens in search of their food. Its prey can be one of the previously mentioned animals that are asleep or distracted. The bat will approach or reach the area where there is less hair or that ideal place to bite. These animals have a kind of thermal sensor in their nose which helps them find the specific place where the blood circulates closest to the skin of their prey.
When they find the ideal area, it will get ready to bite, unlike popular beliefs, bats do not suck blood, but consume it by licking, that is, they lick the blood that is exposed from the animal. The saliva of these bats has a series of chemicals that help the prey not to bleed easily, that the blood does not coagulate quickly and even that there is no capillary thrombosis in the adjacent blood vessels.
Does the bat have predators?
In general, bats do not have many natural predators, most of them are some birds of prey, mammals with a carnivorous diet, some species of snakes and some reptiles of the lizard type that are of considerable size.
In some tropical areas, giant foxes are hunted by snakes when they are resting on a branch, the snake climbs slowly through the branches of the tree until it reaches the bat and thus can catch it. In some other cases, there are some other varieties of animals that could hunt them and make bats an occasional food source, which while not very easy to hunt, if you do, is a great food source.
