The bat has long terrified man. Many legends and stories are made up around their unusual way of life and appearance. Their sharp teeth and nocturnal flight combined to create the illusion of potential danger when encountering them. However, in reality, everything is not so, and only a few rare species that live in certain places feed on the blood of large mammals. The rest are content with insects and have nothing to do with vampirism.
The origin of the species and description
First of all, bats are amazing in that they move through the air, flapping their wings like birds . However, they do this exclusively at night, without using one of the main senses – vision. Of course, they are not birds, because they themselves are viviparous and feed their young with milk. Yes, and they have nothing in common with birds, except for the ability to fly, even feathers.
Bats belong to the class of mammals of the chiroptera order. There are a huge variety of them. According to various sources, from 600 to 1000 species of bats are distinguished. Of course, it is impossible to consider each species separately without being a specialist in these animals.
The main species, the most common and with clear differences, can be counted on the fingers, namely:
- two-tone leather;
- giant evening bat;
- white leaf-nosed bat;
- hog-nosed bat;
- large harelip;
- water bat;
- brown long-eared bat;
- dwarf bat;
- common vampire;
- white-winged vampire;
It is believed that the first bats appeared about 70 million years ago, when small arboreal mammals began to develop membranes on the sides, which later evolved into wings. It is possible that the cause of the formation of membranes was a gene mutation. Scientists believe that the change in the structure of the body of animals occurred quite quickly, since not a single individual of a transitional species has been found to date. That is, the so-called high-speed evolution took place.
Appearance and features
Bats are quite small. The weight of the representative of the smallest species, the pig-nosed bat, is about 2 grams, while the body length of the individual is only 33 mm. This is one of the smallest representatives in general among the animal kingdom. The largest bat is a giant false vampire, whose wingspan is 75 cm, and the body weight of an adult is in the range from 150 to 200 grams.
Different types of bats differ from each other in appearance and structure skulls. But they all have common external signs. The main difference from many animals are wings. They are thin membranes stretched between the front and rear limbs. The wings of bats differ significantly from the wings of birds. They do not have feathers, but they have long fingers, to which membranes are attached.
An interesting fact: the wings are used not only for flying, but also as a blanket during sleep. Bats wrap themselves in them to keep warm.
They also have different hind limbs. They are deployed to the sides, with the knee joints back. The hind limbs are very developed. With their help, bats can hang upside down for a long time. Moreover, it is in this position that they sleep.
Almost all bats have large ears. Which is not surprising for an animal that does not have good eyesight. Ears are used by bats for echolocation and spatial orientation. The animal emits high-frequency subtle sounds, which are reflected from all objects and then perceived by the animal itself. The ears are equipped with a large network of blood vessels that feed them. The eyes of bats, on the contrary, are very small in size. Vision is monochrome and not sharp. Although there are exceptions, for example, the California leaf-beetle relies more on its eyesight than on hearing when hunting.
Most species of bats are not brightly colored. They are usually brown or gray, sometimes dark gray. This is due to the need to be unnoticed while hunting at night. There are also exceptions, for example, some species have white or bright red colors. The hairline of animals is thick, single-tiered. At the same time, the skin membrane is covered with very sparse hair.
Where does the bat live?
Bats are distributed everywhere, with the exception of the polar latitudes, starting from the tundra. There, mice simply have nowhere to hide from harsh climatic conditions, and there is also no necessary amount of food. Even more so, bats are not comfortable among the snows, even considering that they are able to hibernate.
Thus, we can assume that these amazing animals live on all continents except Antarctica. Of course, they differ in species, for example, one lives in Europe, and completely different in South America.
The most important condition for their existence is the presence of a shelter that will allow them to hide daily during daylight hours and sleep. These can be, as is well known, caves. Bats are simply attached to the ceiling of the cave with their paws upside down and spend daylight hours there. At dusk, they begin to fly out to hunt. It is very interesting that when flying out of the cave, bats always fly to the left.
According to the number of mice living in the caves, they promise an accumulation of their droppings on the lower part of the stone niche. Often its accumulation is about a meter.
If there are no caves nearby, then other shelters will do, in nature these are trees: mice find secluded places between twigs, fruits or in dense foliage. The most important thing for them is that sunlight does not fall on them. It is even easier for bats to find shelter in towns and villages — any attic of a residential building will suit them. They are not afraid of people and calmly settle in their houses.
What does a bat eat?
Despite tales of vampirism and the use of bats in horror films such as «From Dusk Till Dawn» or «Dracula», these creatures are completely harmless. They cannot bite a person. However, do not touch bats – they can carry diseases dangerous to humans or pets, such as rabies.
Most species of bats feed on insects: they can eat up to 200 mosquitoes in an hour of hunting. If we consider the ratio of the weight of the animal and the amount of food eaten, then it comes out quite a lot, about a fifth of its own weight.
Some species of bats are larger, it is not enough for them to consume small insects as food, and they are carnivorous – they eat frogs, toads, lizards, small birds and rodents. There are several types of fish-eating bats.
Blood-sucking bats, the so-called vampires, feed on the warm blood of animals, usually they bite livestock. Bites are painless for animals, because together with saliva they secrete a substance that has an analgesic effect. However, they can be dangerous because they carry various diseases that can even kill the animal.
There are also many types of bats that feed on plant foods:
- flower pollen;
- fruits of trees (usually dates, bananas, mangoes);
Such bats. They live in hot tropical countries, where vegetation abounds all year round. Now people are trying to keep exotic animals at home. The bat is no exception and is in demand in the pet market. But if you are not a specialist, you should not do this.
Since these pets are very specific. They require huge returns and strictly defined conditions. From food, carnivores can eat sliced u200bu200bmeat or offal of birds or animals, herbivores should be fed fruit, and drink water and milk. Also, the owners treated the animals with condensed milk as a treat.
Peculiarities of character and lifestyle
Bats lead nocturnal lifestyle. During the day they sleep, and at the same time they usually hide in various shelters, including underground. They are very fond of caves, tree hollows, earthen burrows, as well as quarries and mines, they can hide under tree branches and under bird nests.
They usually live in small colonies of several dozen individuals. Although there are more populated colonies, including those consisting of several different subspecies of bats. Today, the Brazilian folded lip colony, consisting of 20 million individuals, is considered to be the largest in numbers.
In winter, most of the bats hibernate. But some are capable of migrating like birds to warmer climes, covering distances of up to 1000 km. Hibernation, depending on the area, can reach 8 months.
Hibernation occurs upside down, by hanging on its hind legs. This turns out to be convenient so that you can immediately go on a flight, spending less effort and time. No energy is spent on hanging due to the structure of the limbs.
Interesting fact: on the island of Borneo there is a unique carnivorous plant that attracts bats with special sounds. But it does not eat them, but rather provides bats with its inflorescences as a refuge. Animals leave their excrement to the plant, which it uses as fertilizer. In nature, such a symbiosis is unique.
For orientation in space and for hunting, echolocation is used, which helps them maneuver, control the flight altitude and the distance to the walls of the cave. It is believed that during the hunt, bats become aware not only of the distance to the pursued target, but also the direction of its flight, and even what kind of prey it belongs to.
Social structure and reproduction
Living together in a colony does not make bats gregarious. Animals do not perform any joint actions and also hunt exclusively alone. They also do not create families. Two individuals unite only for the moment of mating, and then immediately forget about each other.
Most of the bats that live in temperate climates begin breeding in the spring. Usually there are two to five cubs in a litter, but the exact number is highly dependent on environmental conditions. The female produces offspring once a year. She feeds her young until they develop wings. Growing up in different subspecies lasts different times.
For small subspecies of bats, a period of 6 to 8 weeks is typical until they become independent. For large subspecies of animals, this period can be up to four months. In the first week, the female usually takes the cub with her for night hunting. At the same time, he clings tightly to his mother during the flight. In the weeks that follow, he gets heavy, so she leaves him in the hideout for the duration of the hunt.
An interesting fact: female bats have the ability to control their pregnancy time, as well as delay the birth of offspring. This is necessary for them so that the offspring are born at a time when the amount of food is maximum. Very often, mating occurs in the fall, but fertilization occurs only in the spring.
The life expectancy of bats directly depends on the specific subspecies. Most bats live for 20 years, but there are subspecies with a lifespan of no more than 5 years.
Natural enemies of bats
Bats quite a few enemies. This is primarily due to their small size and nocturnal lifestyle, when much larger predators go hunting. For them, bats serve as excellent prey.
Among predators especially dangerous for bats, it is fashionable to single out the following:
- falcon, golden eagle and other birds of prey;
- carnivorous fish;
In addition to ordinary predators, which mice serve as food, they have enemies of a different kind. Bats are very susceptible to parasites such as mites, fleas or bed bugs. Often, bloodsuckers can kill these animals.
Humanity is very actively fighting rodents and other parasites, calling exterminators and disinfectors to spray the premises with poisons. Bats very often get into the attics of such premises and die from poisoning. This has significantly affected their numbers at the present time.
Not only do they get poisoned from these procedures at home, they also lose some of the food. Insects that live in the area also die from these poisons, and mice may not have enough food. Therefore, it is believed that bats do not live easily, and they need additional protection from humans. However, the specific way of life does not allow even this, because these animals are selective and difficult to follow.
Population and species status
Most species bats have the status of endangered. Some subspecies have the status of vulnerable, requiring constant monitoring.
Basically, the population in the 20th century was negatively affected by the development of agriculture, environmental pollution, and the disappearance of habitats. But at the same time, there were facts of deliberate extermination, destruction of nests and treatment of roofs and attics of houses with repellents. Studies have also been conducted in the United States that have shown that wind farms also affect the number of bats. Bats are killed by collisions with wind turbine blades and from lung damage due to pressure drop near the blades.
But since bats are central to the ecosystem, measures are being taken to protect them. In Europe, they are in fact the only natural regulator of the number of insects that are nocturnal. Thanks to efforts to protect bats, the populations of some subspecies have stabilized, and some have increased.
The European Environment Agency, based on the results of a study of about 6000 nesting sites, concluded that the number of bats in the period from 1993 to 2011 increased by 43%. But these are average figures, and, unfortunately, the number of some subspecies continues to decline.
In the countries of the European Union, all bat species are protected in accordance with EU directives and international conventions. Russia has also signed all international agreements on the protection of bats. Many of them are included in the Red Book. According to Russian law, not only the bats themselves are subject to protection, but also their habitats and shelters. In particular, even the bodies of sanitary supervision and veterinary control cannot take any measures in relation to the settlements of bats in the city.
As measures for the protection of bats, the existence of settlements of animals and their migration routes are taken into account during the construction of parks wind generators. Supervision is carried out in protected areas and informing visitors to protected areas about the rules established for the protection of bats. Artificial lighting is being reduced in their habitats.
To inform citizens about the need to protect animals and to draw people's attention to the problem of their protection, the environmental holiday «International Night of Bats» is celebrated annually on September 21. In Europe, the night of bats has been celebrated for almost 20 years. It has been held in our country since 2003.