INSECTIVOROUS BEASTS(Insectivora), order of mammals; includes 7–8 families, including: slittooths, tenrecs, hedgehogs, shrews, moles, muskrats, about 300 species in total. These are the most ancient and primitive of placental mammals. The body length of insectivores is from 3 to 45 cm. Many representatives have 44 teeth. The body of most animals is covered with thick velvety fur, some have stiff bristly hair and short spines. Many are characterized by specific (musk and odorous) glands. The brain has a small olfactory region, the size of the hemispheres is small. Of the sense organs, the most developed are the organs of smell and touch. Almost everyone's organs of vision are poorly formed. Insectivores are common in Africa, Eurasia, North America and northern South America, but are absent from Australia and almost all of South America. Eight species are listed in the International Red Book.
Chiroptera(Chiroptera) - order of mammals; includes about 850 species, which are divided into two suborders - fruit bats and bats. Chiropterans include small and medium-sized animals, the forelimbs of which are turned into wings. Chiropterans are capable of flight; a thin flying membrane is stretched between the shoulder, forearm, fingers, sides of the body and hind limbs. The auricles are large, many with a well-developed skin projection - the tragus. The tail of most species is long. Skull with a large braincase. The eyes of carnivorous species are large and vision is moderately developed. Most species have small eyes. They navigate in space using ultrasonic echolocation (except for fruit bats). Chiropterans are common on all continents (except Antarctica) and on almost all large islands north of the forest-tundra zone. They are active at dusk and at night. During the day, most species are in shelters: caves, tree hollows, etc. Here they hibernate. The food is very varied. Some species prefer plants and tropical fruits (leaved bats), insects (bats, noctules); vampires feed on the blood of mammals. Herding (formation of colonies) is characteristic of most species. Reproduction in many bats - inhabitants of tropical countries - occurs 2 times, in other species - 1 time. Each litter will produce one baby (rarely 2). In most species, the baby is born large and grows quickly. Bats have few enemies (owls, owls). Most types are beneficial. Bats destroy harmful insects, leaf-nosed insects, by eating the fruits of wild trees, spread tree species, etc. Vampires are considered harmful. Bat droppings are high-quality fertilizer.
A bat is an animal that belongs to the class mammals, order Chiroptera, suborder bats (lat. Microchiroptera).
Bats got their name not because they are relatives belonging to the order of rodents, but most likely due to their small size and the sounds they make, similar to a mouse squeak.
Bat - description, structure. What does a bat look like?
Chiropterans are the only mammals on Earth that can fly. Often this entire squad is mistakenly called bats, but in fact this is not so. The order Chiroptera includes the family of fruit bats (lat. Pteropodidae), which does not belong to the suborder of bats (lat. Microchiroptera). Fruit bats, often called flying dogs, flying foxes, and fruit bats, differ from bats in their structure, habits, and abilities.
Bats are small mammals. The smallest representative of the suborder is the pig-nosed bat (lat. Craseonycteris thonglongyai). Its weight is 1.7-2.0 g, its body length varies from 2.9 to 3.3 cm, and its wingspan reaches 16 cm. It is one of the smallest animals in the world. One of the largest bats is the giant false vampire (lat. Vampyrum spectrum), which has a wingspan of up to 70-75 cm, a wing width of 15-16 cm and a mass of 150-200 g.
The structure of the skull varies among different species of bats, as do the structure and number of teeth. Both depend on the diet of the species. For example, in a nectar-feeding tailless long-tongued leaf-nosed bat (lat. Glossophaga soricina) the facial part of the skull is elongated to accommodate its long tongue, which it uses to obtain food. Bats, like other mammals, have a heterodont dental system, including incisors, canines, premolars and molars. Individuals that eat insects with a thick chitinous coating have larger teeth and longer fangs than those that eat insects with a soft shell. Small insectivorous bats can have up to 38 small teeth, while vampires have only 20. Vampires do not require many teeth since they do not need to chew their food, but their fangs, designed to make a bleeding wound on the victim's body, are razor-sharp. Fruit bats have upper and lower cheek teeth that resemble mortars and pestles used to crush fruit.
Many bats have large ears, such as the brown long-eared bat. Plecotus auritus), and bizarre nasal projections, like those of horseshoe bats. These features affect the bat's echolocation abilities.
During evolution, the forelimbs of bats were transformed into wings. The humerus has shortened and the fingers have lengthened; they serve as the frame of the wing. The first finger with a claw is free. With its help, animals move in the shelter and manipulate food. In some species, such as clouded bats (Furipteridae), the first digit is nonfunctional. The second, third and fourth fingers strengthen the part of the wing between the first and fifth and form the interdigital membrane, or wing tip. The fifth finger is extended across the entire width of the wing. The humerus and shorter radius bones support the body membrane, or base of the wing, which functions as a load-bearing surface. The speed of the bat depends on the shape of the wings. They can be highly elongated or slightly elongated. The shape of the wing can be used to judge the bat's lifestyle. Wings with a slight aspect ratio do not allow you to develop high speed, but make it possible to maneuver well among the treetops. The highly extended wings are designed for high-speed flight in open space.
Small and medium-sized bats fly at speeds of 11 to 54 km/h while searching for prey. The fastest flying animal is the Brazilian folded lip (lat. Tadarida brasiliensis) from the genus of bulldog bats, which is capable of speeds of up to 160 km/h.
Taken from: www.steveparish-natureconnect.com.au
The hind limbs of bats, unlike other mammals, are turned to the sides with the knee joints backward. On them, animals hang in shelters with the help of well-developed claws.
Some species are able to walk on all four limbs. For example, an ordinary vampire (lat. Desmodus rotundus) during a hunt, landing on the body of the prey or next to it, it approaches on foot to the place where it delivers the bite.
Bats have tails of varying lengths:
- partially enclosed in the interfemoral membrane, with a free tip located on top of it, as in sacwings (lat. Emballonuridae);
- completely enclosed in the interfemoral membrane, like in the bats (lat. Myotis);
- protruding beyond the interfemoral membrane, as in folded lips (lat. Molossidae);
- long free tail, like that of mousetails (lat.Rhinopoma).
The body and sometimes the limbs of mammals are covered with hair. A bat's fur can be smooth or shaggy, short or not very short, sparse or thick.
The color of bats is dominated by gray, brown, and black tones. Some animals are lighter colored - fawn, whitish, yellowish. Occasionally bright specimens are also found. For example, in the Mexican fish-eating bat (lat. Noctilio leporinus) yellow or orange fur.
Taken from: www.mammalwatching.com
There are white bats with yellow ears and nose - these are Honduran white bats (lat. Ectophylla alba).
Taken from: faculty.washington.edu
In nature, there are bats with a body not covered with hair. There are two known species of bare-skinned bats from Southeast Asia and the Philippines (lat. Cheiromeles torquatus And Cheiromeles parvidens) they are almost completely hairless, with only sparse hairs remaining.
Bats have unique hearing. It is the leading sensory organ in these animals. For example, false horseshoe bats (lat. Hipposideridae) catch the rustle of insects swarming in the grass or under a layer of leaves. The ears of many bats have a tragus - a narrow cutaneous-cartilaginous outgrowth that rises from the base of the ear. It serves to enhance and better perceive sound.
Taken from: blogs.crikey.com.au
Bats' vision is poorly developed. There is no color vision at all. But still, bats are not blind, and some even see quite well. For example, the Californian leaf-nosed bat (lat. Macrotus californicus) sometimes, with appropriate lighting, searches for prey using the eyes.
Bats have not lost their sense of smell. By the smell of a female Brazilian folded lip (lat. Tadarida brasiliensis) find their young. Some pipistrelle bats distinguish members of their colony from strangers. Large nightlights (lat. Myotis myotis) and New Zealand bats (lat. Mystacina tuberculata) smell prey under a layer of foliage. New World leaf-noses (lat. Phyllostomidae) find the fruits of nightshade plants by smell.
How do bats navigate in the dark?
The main means of orienting bats in space (for example, in dark caves) is echolocation. Animals emit ultrasonic signals that bounce off objects and echo back. The animal makes sounds originating in the throat with its mouth or directs them into the nose, emitting them through the nostrils. In such individuals, the nostrils are surrounded by bizarre projections that form and focus sound.
People only hear how bats squeak, because the ultrasonic range in which these animals transmit echolocation signals is inaccessible to the human ear. Unlike a human, a bat analyzes the signal reflected from an object and determines its location and size. The mouse echo sounder is so accurate that it detects objects with a diameter of 0.1 mm. In addition, winged mammals clearly distinguish between various objects: for example, different types of trees. Bats hunt using echolocation. Using reflected ultrasonic waves, winged hunters not only find their prey in complete darkness, but also determine its size and speed. While searching for prey, the frequency of sounds reaches 10 vibrations per second, increasing to 200-250 just before the attack. In addition, the bat can squeak while inhaling, exhaling, and even while chewing food. Before the discovery of ultrasound, these mammals were thought to have extrasensory perception.
Representatives of the suborder are capable of producing both low-frequency and high-frequency sounds, and simultaneously. The animal screams and listens at a speed incomprehensible to humans. Some bats, hunting nocturnal insects, emit up to 250 calls per second when approaching them. Some potential victims (crickets) have developed the ability to hear the squeak of a bat in advance and respond to it by feinting or falling to the ground.
By the way, echolocation is developed not only in bats, but also in seals, shrews, moths, and also in some birds.
Where do bats live?
Bats are widespread throughout the world, with the exception of Antarctica, the Arctic and some oceanic islands. These animals are most numerous and diverse in the tropics and subtropics.
Bats are nocturnal or crepuscular animals. During daylight hours, they hide in shelters, which can be located in a variety of places underground and above ground. These can be caves, rock crevices, quarries, adits, various buildings built by man. Many species of bats live in trees: in hollows, bark crevices, branches, and foliage. Some mice take refuge in original shelters, for example, under bird nests, in bamboo stems and even in cobwebs. American suckers (lat. Thyroptera) spend the day in young rolled leaves, which unfold after the animals leave their home. Leaf-nosed builders (lat. Uroderma Peters), by biting the leaves of palm trees and other plants along certain lines, they get something like an awning from them.
Some species of bats prefer to live alone or in small groups, for example, the lesser horseshoe bat. Rhinolophus hipposideros), but mostly they keep in colonies. For example, females of the great bat (lat. Myotis myotis) gather in colonies from several tens to several thousand individuals. The record for the number of members is one of the colonies of Brazilian folded lips (lat. Tadarida brasiliensis), numbering up to 20 million individuals.
How do bats winter?
Bats that live in cold and temperate latitudes hibernate during the cold season, which can last up to 8 months. Some species migrate seasonally over distances of up to 1000 km, such as the red hairtail (lat. Lasiurus borealis).
Why do bats sleep upside down?
Chiropterans stand out among mammals not only because they can fly, but also because they know how to rest: during daytime rest or hibernation, bats hang upside down on their hind legs. This position allows the animals to instantly take off straight from their starting position, simply falling down: this way, less energy is wasted, and time is saved in case of danger. Hanging upside down, bats cling to wall ledges, tree branches, etc. with their claws. Being in this position, animals do not get tired, because the tendon mechanism for closing the claws of their hind limbs is designed in such a way that it does not require the expenditure of muscle energy. Some species, when settling down to rest, wrap themselves in their wings. Species such as the great bats gather in dense heaps, and the lesser horseshoe bats always hang on the ceiling or arches of the cave at some distance from each other.
What do bats eat?
Most bats are insectivores. Some catch insects on the fly, others pick up bugs sitting on the foliage. Among tropical species, there are those that feed exclusively on fruits, pollen and nectar of plants. But there are also varieties that eat both fruits and insects. For example, the New Zealand bat (lat. Mystacina tuberculata) feeds on various invertebrates: insects, earthworms, centipedes and, but, at the same time, consumes fruits, nectar and pollen. The diet of fish-eating bats (lat. Noctilio) consists of fish and other aquatic inhabitants. Panamanian big leaf-nosed bat (lat. Phyllostomus hasstatus) eats small birds and mammals. There are also species that feed exclusively on the blood of wild and domestic animals, some birds, and sometimes humans. These are vampire bats, among which there are 3 types: hairy-legged (lat. Diphylla ecaudata), white-winged (lat. Diaemus youngi) and ordinary (lat. Desmodus rotundus) vampires. Other types of vampires live in other places around the globe, but they don’t really drink blood.
Types of bats, photos and names
Below is a brief description of several species of bats.
- White leaf-nosed bat(lat. Ectophylla alba)
A tailless species that belongs to the genus of white leaf-nosed insects. These are small animals with a body length of 3.7-4.7 cm and a weight of no more than 7 grams. Female leaf-nosed insects are smaller in size than males. The color of the animal’s body corresponds to its name: the boiling white back turns into a grayish sacrum, the lower abdomen is also gray in color. The animal's nose and ears have a yellow tone, and the eyes are emphasized by a gray frame around them. White leaf-nosed bats live in South and Central America, namely in countries such as Costa Rica, Honduras, Nicaragua, and Panama. Animals prefer moist evergreen forests, climbing no higher than seven hundred meters above sea level. Typically, these white bats live solitary lives or live in small groups of no more than 6 individuals. The animals feed at night. The diet of these bats includes fruits and some types of ficus.
- Giant noctule(lat. Nyctalus lasiopterus)
This is the largest species of bat in Russia and European countries. The body length of the animal varies from 8.4 to 10.4 cm, and the weight of the bat is 41 – 76 g. The wingspan of the animal reaches 41-46 cm. The giant noctule has a brownish or fawn-red color on the back and a lighter belly. Darker colors predominate on the head behind the ears. The bat lives in forests, and its range extends from France to the Volga region and the Caucasus. The species is probably also found in the Middle East. Often the animal inhabits tree hollows together with other representatives of the suborder, and less often forms its own colonies. The wintering grounds of this species are unknown; apparently the animals make long-distance seasonal flights. In nature, the bat feeds on fairly large insects (butterflies, beetles), as well as small passerine birds, which it catches in the air at fairly high altitudes. This bat is listed in the Red Book.
- Hog-nosed bat (lat.Craseonycteris thonglongyai)
This is the smallest bat in the world, which due to its modest size is called the bumblebee mouse. The body length of the animal is 2.9-3.3 cm, and the weight does not exceed 2 grams. The mammal's ears are quite large, with a large tragus. The nose looks like a pig's snout. The color of the animal is usually grayish or dark brown with a slight shade of red, the belly of the animal is lighter. Hog-nosed bats are endemic to southwestern Thailand and nearby areas in Myanmar. The animals hunt in groups of up to five individuals at night. They fly over bamboo and teak trees in search of insects that sit on the leaves of the trees, and when they find food, they hover above the prey right in the air due to their small size and the structure of their wings. The number of pig-nosed bats in the world is extremely low. These animals are among the ten rarest species on Earth and are listed in the International Red Book.
Taken from: www.thewildlifediaries.com
- Two-color leather (two-color bat) (lat.Vespertilio murinus)
It has a body length of up to 6.4 cm and a wingspan of 27 to 33 cm. The bat weighs from 12 to 23 grams. The animal got its name because of the color of its fur, which combines two colors. The back is colored in shades from red to dark brown, and the belly is white or gray. The ears, wings and front part of the animal are black or dark brown. These bats live throughout Eurasia - from England and France to the Pacific coast. Northern border of the range: Norway, Central Russia, Southern Siberia; southern border: southern Italy, Iran, Himalayas, Northeast China. The habitat of the two-color leatherback is mountains, steppes and forests. In Western European countries, these bats are often found in large cities. Two-colored bats do not mind being in the neighborhood with other species of bats, with which they share common shelters: attics, eaves, tree hollows, rock cracks. Animals hunt for caddisflies, moths and other small insects throughout the night. The species is endangered and protected in many countries.
Taken from the website: www.aku-bochum.de
- Greater harelip (fish-eating bat)(lat.Noctilio leporinus )
It has a body length of 6.5-13.2 cm and weight from 60 to 78 g. The colors of males and females differ: the former have a reddish or bright red body, the latter are painted in dull grayish-brown shades. A light stripe runs from the back of the head to the end of the animal’s back. These bats are found from southern Mexico to northern Argentina and are found in the Antilles, southern Bahamas and the island of Trinidad. Bats settle near water in caves, rock cracks, and also climb into hollows and tree crowns. Greater harelips feed on large insects and aquatic inhabitants of fresh water bodies: fish and crustaceans. Sometimes they can hunt during the day.
Taken from: reddit.com
Taken from: mammalart.wordpress.com
- Water bat (Dobanton bat)(lat.Myotis daubentonii)
It got its name in honor of the French naturalist Louis Jean-Marie Daubanton. This small animal has a body length of no more than 4.5 - 5.5 cm and weighs from 7 to 15 g. The wingspan is 24 - 27.5 cm. The color of the fur is inconspicuous: dark, brownish. The upper part is darker than the lower part. The animal's habitat extends from Great Britain and France to Sakhalin, Kamchatka and the Ussuri region. The northern border runs near 60°N, the southern - from southern Italy, along southern Ukraine, the lower Volga, through northern Kazakhstan, Altai, northern Mongolia, to the Primorsky Territory. The life of a bat is associated with bodies of water, although animals are also found far from them. During the day they can climb into a hollow or attic, and at nightfall they begin to hunt. These bats fly slowly, often fluttering over the surface of water bodies, and catch small insects, mainly mosquitoes. If there is no body of water nearby, then water bats hunt among the trees. By destroying blood-sucking insects, water bats help fight malaria and tularemia.
- Brown long-eared bat ( aka common long-eared bat)(lat. Plecotus auritus)
It has a body length of 4-5 cm and a weight of 6-12 g. The most characteristic thing in the appearance of the long-eared bat is its huge ears. The body is covered with uneven, dull fur. The long-eared bat's habitats cover almost all of Eurasia, including Portugal in the western part of its range and up to the Kamchatka Peninsula in the eastern part. The brown long-eared bat is also found in northern Africa, Iran and central China. The lifestyle of bats is sedentary. These winged animals overwinter not far from their places of residence in the summer, inhabiting caves, various cellars, well log houses and hollows of powerful trees, sometimes found in the attics of houses that have been insulated for the winter. A bat with large ears flies out to hunt in complete darkness and hunts until the sun rises.
- Dwarf pipistrelle ( aka small or small-headed bat) (lat. Pipistrelluspipistrellus)
Quite a numerous species belonging to the genus of inexperienced bats, the family of smooth-nosed bats. This is the smallest species of bats in Europe. The body of the dwarf pipistrelle resembles that of a mouse, its length is 38-45 mm, and the tail length is 28-33 mm. The weight of the dwarf pipistrelle is usually 3-6 g. The wingspan of this small bat reaches 19-22 cm. The body is covered with short, even hair, which is colored brown in the European form of the animal, and pale grayish-fawn in the Asian form. The lower part of the body is lighter in color. The dwarf pipistrelle is widespread in Eurasia: from west to east from Spain to Western China, and from north to south from southern Norway to Asia Minor and Iran. In addition to Eurasia, this species of bat is found in North Africa. Settles in places associated with human habitation, does not occur in the depths of forests and steppes, avoids caves, and sometimes settles in tree hollows. In winter, bats make seasonal migrations. Adult males are extremely rare in the spring and summer, as they stay solitary or gather in small groups separately from females and young individuals. Bats hunt after sunset. They fly low, in the lower part of tree crowns. This tiny mouse's diet consists of small insects. The dwarf pipistrelle is one of the most useful bats in the Eurasian fauna.
- Great horseshoe bat(lat. Rhinolophus ferrumequinum)
The dimensions of the animal are 5.2-7.1 cm, the wingspan reaches 35-40 cm, and the weight of the bat is 13-34 g. The color of the back varies depending on the habitat from dark chocolate to pale smoky fawn. The animal's belly is whitish with a gray tint, lighter than the color of the back. Young animals have a uniform grayish color. The species is widespread in northern Africa (Morocco, Algeria), in Eurasia, the habitat of the horseshoe bat extends from Great Britain and Portugal through the mountainous regions of Central Europe, covers the Balkans, the countries of Asia Minor and Western Asia, the Caucasus, the Himalayas, Tibet, and ends in the south of China, Korea peninsula and Japan. On the territory of Russia, this bat is found in the Crimea and the North Caucasus, covering a range from the Krasnodar Territory to Dagestan. The usual places of settlement of the horseshoe bat are mountain crevices, grottoes, basements and ruins, as well as caves. In Central Asia, these animals live under the domes of tombs and mosques. Bats live relatively sedentary lives, making local seasonal migrations. They winter in damp caves and dungeons. They hunt low above the ground for moths and small beetles. The great horseshoe bat is listed in the Red Book of Russia.
- Common Vampire ( aka big bloodsucker, or Desmod) (lat.Desmodus rotundus )
The most numerous and famous species of real vampires. It is largely thanks to this genus that bats have their bad reputation. An ordinary vampire does indeed feed on blood, including drinking human blood. This animal is small in size: the length of the bat is 8 cm, weight is 50 g, wingspan is 20 cm. Bloodsucking vampires live in large colonies. During the day they sleep in the hollows of old trees and caves. An ordinary vampire flies out to hunt late at night, when his future victims are immersed in deep sleep. It attacks large ungulates such as,. It can also bite a person sleeping in an open area or in a house with open and unprotected windows. Using hearing and smell, vampire bats find a sleeping victim, sit on it or next to it, crawl to the place where the vessels come close to the surface of the skin, bite through it and lick the blood flowing from the wound. A special secret contained in the saliva with which the vampire wets the victim’s skin makes the bite painless and affects blood clotting. As a result, the victim may die from blood loss, since the blood flows out for a long time without clotting. But this is not the only danger of an ordinary vampire. Its bite can transmit the virus of rabies, plague and other diseases. Vampires themselves suffer from rabies. The spread of disease within a species occurs, among other things, due to the tendency of vampires to share regurgitated blood with hungry fellow tribesmen, a habit that is extremely rare among animals. Vampire bats live only in the tropics and subtropics of Central and South America. There are other types of vampires in other places around the world, but they do not feed on blood. Thanks to these three species of bats, a negative attitude towards bats, which are not only harmless, but also useful animals, has taken root.
Known approx. 1000 species of bats. The smallest of them, the pig-nosed bat ( Craseonycteris thonglongyai), is the smallest living mammal. Its length can reach only 29 mm (no tail) with a mass of 1.7 g and a wingspan of 15 cm. The largest bat is the Kalong flying fox ( Pteropus vampyrus) up to 40 cm long (no tail) and weighing 1 kg with a wingspan of 1.5 m.
As experiments have shown, bats do not distinguish colors, and since their typical activity is nocturnal or crepuscular, a brightly colored skin is useless for them. The color of most of these animals is brownish or grayish, although some of them are red, white, black or even piebald. Their fur is usually formed by longer guard hairs and thick underfur, but two species of naked-skinned bats ( Cheiromeles) are almost completely hairless. The tail of bats can be long, short, or completely absent; it is partially or entirely enclosed in a skin caudal membrane extending from the hind limbs, or is completely free.
Among mammals, only bats are capable of active flapping flight. The flying squirrel rodent, the woolly wing and some other “flying” animals do not actually fly, but glide from higher to lower heights, stretching the folds of skin (patagial membranes) that protrude from the sides of their body and are attached to the front and hind limbs (in the woolly wing they reach to the ends of the toes and tail).
Most bats cannot match the flight speed of faster birds, but nocturnal bats ( Myotis) it reaches approximately 30–50 km/h, in the great brown leatherback ( Eptesicus fuscus) 65 km/h, and the Brazilian folded lip ( Tadarida brasiliensis) almost 100 km/h.
Appearance and structure.
The scientific name of the order, Chiroptera, is composed of two Greek words: cheiros - hand and pteron - wing. They have very elongated bones of the forelimb and especially the four fingers of the hand, which support and, with the help of muscles, move the elastic membrane of skin that runs from the sides of the body forward to the shoulder, forearm and fingertips, and back to the heel. Sometimes it continues between the hind limbs, forming a caudal, or interfemoral, membrane, which provides additional support in flight. Only the first finger, equipped with a claw, is not elongated in the hand. The toes of the hind limb are approximately the same as those of other mammals, but the calcaneus is elongated into a long spur that supports the posterior edge of the tail membrane. The hind limbs are turned outward, probably to facilitate landing upside down and hanging on the toes; This causes the knees to bend backward.
Fruit bats.
The fruit bats (Pteropodidae) include the largest bats - flying foxes ( Pteropus). In total, the family has 42 genera and 170 species, which are distributed from tropical Africa to Australia and the Pacific Islands. Most feed on fruits, some, such as the Australian fruit bat ( Syconycteris), – nectar and pollen. Species of this family have large eyes, and they navigate using vision, only flying dogs or night fruit bats ( Rousettus), use a simple form of echolocation. Male African hammerhead fruit bat ( Hypsignathus monstrosus) is distinguished by a large head with a hammer-like snout, and its huge larynx occupies a third of the body cavity. He uses a loud croaking cry, among other things, to attract females to the mating site, to “leak.”
Free-tailed bats
(Rhinopomatidae) from North Africa and South Asia are small animals with a long tail, similar to a mouse. This family has one genus and three species.
Case-tailed or sac-winged bats
(Emballonuridae) are small to medium-sized animals. They feed on insects and are found in tropical regions of both hemispheres. 11 genera and 51 species are known. One species from Central and South America is distinguished by its pure white color, and it is called the white casetail ( Diclidurus albus).
Hog-nosed bats
(Craseonycteridae) are the smallest modern mammals. The only species of this family was discovered in a cave in Thailand in 1973.
Fish-eating bats
(Noctilionidae) from the tropical regions of America and the West Indies are relatively large reddish-brown animals with long hind legs and feet, but short muzzles, reminiscent of a bulldog. One genus with two species is described. The already mentioned great fisher, or Mexican fish-eating bat, feeds mainly on fish.
Slit-faced bats
(Nycteridae) live in Africa, on the Malay Peninsula and the island of Java. These are small bats with a deep longitudinal groove in the middle of the muzzle. One genus with 12 species has been described.
False vampires
(Megadermatidae) are so named because they were once thought to be bloodsuckers, but in fact they are carnivores, feeding on birds, mice, other chiropterans, lizards and insects. They gather to rest in caves, houses, tree hollows, abandoned wells and in dense tree crowns. Yellow-winged false vampire ( Lavia frons), which eats insects, is distinguished by huge ears and long, silky fur with orange, yellow and green tints, which fades after the death of the animal.
Horseshoe-nosed
(Rhinolophidae) are widespread in the Old World. The nostrils of these bats are surrounded by complex skin projections, one of which resembles a horseshoe, hence the name of the whole group. One genus of the family unites 68 species of insectivorous bats.
False horseshoe bats
(Hipposideridae) are closely related to horseshoe bats, and some experts consider them to be a subfamily of the latter. Their skin growths around the nostrils are somewhat simpler. The family consists of 9 genera and 59 species.
Chinfolias
(Mormoopidae) live in the tropics of the New World. Their tail protrudes beyond the tail membrane. There are 8 species of these insectivorous mice, classified into two genera.
American Leaf-nosed
(Phyllostomidae) are found only in warm areas of America. Almost all of these creatures are characterized by a triangular or spear-shaped skin projection at the end of the snout directly behind the nostrils. This group includes the false vampire ( Vampyrum spectrum), the largest bat of the New World, approx. 135 mm with a weight of 190 g and a wingspan of up to 91 cm. The Godman longnose ( Choeroniscus godmani) a long, extensible tongue equipped at the end with a brush of hard hairs; With its help, he extracts nectar from the corolla of tropical flowers that open at night. This family also includes the builder leaf beetle ( Uroderma bilobatum), who builds an individual shelter for himself, cutting the veins on a banana or palm leaf so that its halves sag, forming a canopy that protects from rain and sun. The family includes 45 genera with 140 species.
Vampire
(Desmodontidae) feed exclusively on the blood of warm-blooded animals (birds and mammals). They are found in tropical areas of America from Mexico to Argentina. These are rather small animals with a body length (i.e. head and body) rarely exceeding 90 mm, a mass of 40 g and a wingspan of 40 cm. Many bats are unable to move on a hard surface, but vampires crawl quickly and deftly. Having landed near the intended victim or directly on it, they move to a convenient area on its body, usually lightly covered with hair or feathers, and, using their extremely sharp teeth, quickly and painlessly bite through the skin. The victim, especially one who is sleeping, usually does not notice this. The vampire does not suck blood, but only applies the underside of the tongue to the protruding drop, and it, due to capillary forces, enters the longitudinal grooves running along the tongue. Periodically drawing its tongue into its mouth, the animal feeds. There are 3 genera in the family, one species in each.
Funnel-eared
(Natalidae) - small, fragile insectivorous bats with very long hind limbs and thin flight membranes. They are found in tropical areas of America. 1 genus with 4 species is described.
Smoky bats
(Furipteridae), tiny animals from South and Central America, easily recognizable by their vestigial thumb. Two genera are described, one species in each.
American sucker-footed bats
(Thyropteridae), inhabitants of the tropical regions of America. Concave suction discs are located at the base of the first finger of the hand and on the sole of the hind leg. They allow the animals to attach to a smooth surface, and any suction cup can support the weight of the entire animal. The only genus includes 3 species.
Madagascar suckers
(Myzopodidae) are found only in Madagascar. The only species of these bats is not closely related to the American suckerfoots, but is equipped with similar suckers.
Leather
(Vespertilionidae) are represented by 37 genera and 324 species. They are found in temperate and tropical zones around the world, and in many temperate areas they are the only bats. Almost all species feed exclusively on insects, but the piscivorous bat, true to its name, eats mainly fish.
Casewings
(Mystacinidae) are represented by a single species – the New Zealand sheathwing.
Folded-lipped bats
(Molossidae) are strong insectivorous animals with long narrow wings, short ears and short shiny fur. Their tail protrudes strongly beyond the interfemoral membrane and is longer than the elongated hind limbs. These fast fliers are found in warm and tropical regions of both hemispheres. They rest in groups ranging from a few individuals to many thousands of animals in caves, rock crevices, buildings and even under galvanized iron roofs, where the tropical sun heats the air to very high temperatures. 11 genera and 88 species have been described. This family includes the largest bat in the United States - the great eumops ( Eumops perotis), also called the mustachioed bulldog bat. The length of her body (head and torso) is approx. 130 mm, tail - 80 mm, weight up to 65 g, wingspan can exceed 57 cm. Two species of this family, bare-skinned bats from Southeast Asia and the Philippines ( Cheiromeles torquatus And C. parvidens), are unique among bats for their virtually hairless body. Thousands of Brazilian folded lips were used in one of the research projects during the Second World War as “suicide arsonists.” This project, called the X-Ray, involved attaching small incendiary time bombs to the animal's torso, keeping the animals hibernating at 4°C and parachuting them in self-expanding containers over enemy territory, where they were supposed to were crawling into houses. Shortly before the end of the war, the development of such weapons, aimed, in particular, against Japanese cities, was abandoned.
Paleontological history.
Chiropterans are a very ancient group. They lived in the Old and New Worlds already in the Middle Eocene, ca. 50 million years ago. They most likely evolved from arboreal insectivores in the Eastern Hemisphere, but the oldest fossil bat, Icaronycteris index, discovered in Eocene sediments of Wyoming.
Encyclopedic YouTube
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✪ The Most Epic AIR ATTACKS CAUGHT ON CAMERA
✪ Chiropterans in the aspect of biosafety - Maria Orlova / PostNauka
✪ Snakes (1962). Educational film on zoology
✪ 1.1 Insect wings and bird wings
✪ Bats and aerodynamics
Subtitles
Origin and evolution
Chiropteran fossils are known from early Eocene deposits of the United States.
According to modern data, bats appeared no later than the early Eocene and even then occupied the ecological niche of nocturnal hunters of airspace. Fossil remains dating back to the Miocene indicate a powerful species radiation of bats during this era. But overall, bats are one of the rarest groups of mammals in the fossil record.
The question of how exactly bats evolved from terrestrial ancestors has been worrying biologists for decades. Although many of the chiropterans feel insecure on the ground, there are species that run quickly, leaning on the folds of their wings. There are also those who can swim and take off from the water.
Spreading
Chiropterans are very widespread. Apart from the tundra, subpolar regions and some oceanic islands, they are found everywhere. More numerous in the tropics. Chiropterans are endemic to many oceanic islands in the absence of land mammals, as they are able to travel long distances over the sea.
The population density of bats in mid-latitudes is 50-100 per square kilometer, in Central Asia - up to 1000. At the same time, the habitats of no more than two or three species of representatives of the common bat family extend to the northern border of the taiga; in the southern part of the USA and the Mediterranean there are species already several dozen, and in the Congo and Amazon basins - several hundred species. The reason for this sharp increase in the number of species is the high density of bats in the tropics and the resulting aggravation of their competitive relationships.
The forelimbs are transformed into wings, but in a significantly different way than in birds. All fingers of the “hands”, except the first, in bats are greatly elongated and, together with the forearm and hind limbs, serve as a frame for the skin membrane that forms the wing. Most species have a tail, which is usually also covered by a flight membrane. The membrane is permeated with blood vessels, muscle fibers and nerves. It can take a significant part in the gas exchange of bats, since it has a significant area and a fairly small air-hematic barrier. In cold weather, bats can wrap themselves in their wings like a cloak. The bones of chiropterans are small and thin, which is an adaptation for flight.
The head has a wide mouth slit, small eyes and large, sometimes complexly arranged auricles with a skin outgrowth (tragus) at the base of the ear canal. Nectarivorous species have adaptations to this type of feeding: an elongated conical muzzle and a long thick tongue, with many bristle-like papillae at the end that help lick pollen.
The hairline is thick, single-tiered. The skin membrane is covered with sparse hairs. The ulna and often the fibula are vestigial; the radius is elongated and curved, longer than the humerus; well developed clavicle; The shoulder girdle is more powerful than the girdle of the hind limbs. The sternum has a small keel. Due to feeding on animals or soft fruits, the digestive tract is only 1.5-4 times the length of the body, the stomach is simple, and the cecum is often absent.
The organs of touch are varied and, in addition to the usual tactile corpuscles and vibrissae, are represented by numerous thin hairs scattered on the surface of the flying membranes and auricles. Vision is usually weak and of little importance for orientation; the exception is fruit bats, which use it to search for fruits. Chiropterans are colorblind. Hearing is extremely subtle. The range of audibility is huge, ranging from 12 to 190,000 Hz.
Adaptations for flight
The bat wing skeleton consists of highly elongated forearm bones and fingers that support and stretch the thin membrane of the wing. It is very elastic and can be stretched four times without breaking. The membrane continues to the hind limbs, which are somewhat smaller than those of similar-sized land mammals. The flying membrane of skin is stretched between the second to fifth fingers of the forelimbs, forearm, shoulder, sides of the body, hind limbs and tail. The short first digit of the forelimbs has a claw. Many bats also have a tail membrane between their hind limbs. A unique bone called the spur extends from the heel and supports the trailing edge of the webbing. By moving their fingers, arms, legs and spurs, bats can control their wings in countless ways, making them excellent fliers.
Contrary to popular belief, bats can take off not only from high points (ceiling of a cave, tree trunk), but also from flat ground and even from the water surface. In this case, takeoff begins with an upward jump, which occurs as a result of a strong impetuous movement of the forelimbs.
Echolocation
To navigate in space, many species of bats use echolocation: the ultrasonic pulses they emit are reflected from objects and captured by the ears. In flight, bats emit ultrasounds with a frequency of 30 to 70 thousand Hz. Sounds are produced intermittently, in the form of pulses lasting 0.01-0.005 seconds. The pulse frequency varies depending on the distance between the animal and the obstacle. When preparing for flight, the animal emits from 5 to 10, and in front of an obstacle - up to 60 pulses per second. The ultrasounds reflected from the obstacle are perceived by the animal’s hearing organs, which provides orientation in flight at night and the prey of flying insects. The intensity of ultrasonic signals is very high, for example, in the Malayan bat it is 145 decibels, so it is good that the human ear is not able to hear them.
Echolocation allows bats to control their flight altitude, maneuver in dense forest, find their way to a roost, and confidently pursue prey. When flying in an environment full of obstacles, for example, in the thickets of the jungle, each ultrasonic cry causes many reflected sounds, however, it is likely that the animals simultaneously detect only echo signals from the nearest object and, possibly, from objects located on the same line somewhere at a distance, but not from everyone. During the hunt, they become aware not only of the distance to the target, but also the direction of its flight, as well as what type of prey it belongs to. The exact distance from which the bat can determine this is not yet known, and perhaps it depends on the biospecies of the hunter, the size of the prey, and the speed of the hunter and prey.
In some bats, in particular frugivores, as well as those that feed on large insects, spiders, scorpions and small vertebrates, echolocation signals are weaker and very short. Echolocation devices differ for each species of chiroptera, in some they differ slightly, and in others they differ very much.
In addition to ultrasound, bats also use regular sound signals, mainly for communication. These sounds usually lie at the threshold of human perception. Children hear the whirring and squeaking of most species, while older people hear only a few.
Chiropterans have also discovered complex songs that are performed for different purposes: when a male is courting a female, to recognize each other, to indicate social status, to determine the boundaries of territory and resistance to strangers, and when raising young. These songs are reminiscent of birds, and among mammals, bats are the only ones other than humans that use such complex vocal sequences to communicate. However, songs lie in the ultrasonic range, and a person can only hear those fragments that were sung in lower frequencies.
Lifestyle
Since bats lead a secretive lifestyle and are small in size, they can be seen infrequently. Many of them are nocturnal or crepuscular animals. Some species hibernate in winter, others migrate.
Chiropterans can be found in caves and grottoes, in earthen burrows, in wells, in hollow trees, in piles of stones, in attics, in bell towers, under the roofs of houses and in bird nests, under bridges and in other places. The roost of herbivorous species is not a pleasant place. Animals, flocking to a cave to rest, carry with them pieces of fruit, which, along with droppings, are often dropped to the bottom of the cave. The mud partially blocks the entrance to the cave, and a stagnant lake forms there, which, together with the mud, turns into a fetid mess.
In caves or on tree branches, bats hang upside down, clinging to their hind legs. This provides them with safety from terrestrial predators.
Nutrition
During the waking period, metabolism is very intense, and often in a day bats eat food in an amount approximately equal to the weight of their own body.
Bats feed on insects (most bats are insectivores, there are about 625 species), fruits or fish; different species specialize in different foods. There are also predators that feed mainly on small vertebrates (birds, rodents, amphibians, reptiles and chiropterans) - some representatives of the spear-nosed families ( Megadermatidae), alkali-faced ( Nycteridae) Old World and leaf-nosed ( Phyllostomidae) New World. Sometimes certain species of the families of piscivorous bats prey on small fish and aquatic arthropods ( Noctilionidae, Noctilio leporinus) and Smooth-nosed bats ( Vespertilionidae, Myotis vivesi, Myotis adversus).
The predominantly frugivorous and nectarivorous forms include about 260 species Chiroptera(Old World fruit bats and several subfamilies Phyllostomidae New World). The color of fruits and flowers (greenish or brown) is not important for bats due to their color blindness; they search for food by shape and smell. Often the animals hang on one paw and bite off small pieces from the fruit held in the other paw. Some feed on flowers, eating them whole, others drink nectar. Since the nectar eaten is rich in sugars and poor in other biologically active substances, the diet of nectarivores also includes pollen, which they lick, and, sometimes, insects. Bats can also drink fermented palm sap collected in buckets by residents of Sri Lanka and the Philippines to make toddy. Intoxication causes such animals to fly unevenly, in a zigzag manner.
Hunting methods are varied. The flight of insect hunters seems unstable due to how fast they fly and how much prey they catch. In laboratory conditions, they show results of up to 15 fruit flies per minute. To identify and catch an insect, they need only half a second, and at the same time they perform various maneuvers: loop, turn, dive, etc. The wings and interfemoral membranes are also used in hunting, delaying, catching prey and directing it to the mouth. Piscivorous species hunt using echolocation to locate fish, swooping down and catching them with their clawed hind legs from the surface of the water.
Some species use cheek pouches to carry prey. For example, a fishing bat chews a caught fish into pieces, places it in its cheek pouches and continues hunting.
Geophagy
Studies carried out on bats by an international team of zoologists led by Christian Voigt from the Leibniz Zoological Institute in Berlin showed that the list of functions of minerals as biologically active substances also includes detoxification (plant poisons are formed in large quantities in the green parts of fruits). Scientists decided to test how bats solve these problems with the help of licks, which in the tropics are often combined with the release of mineral water to the surface.
To do this, zoologists caught fruit-eating bats of the species Artibeus obscurus and omnivores Carollia perspicillata, capable of feeding on both fruits and insects. Catching and collecting small pieces of wing tissue was carried out both simply in the Amazon jungle and directly next to mineral licks. After this, the content of nitrogen and mineral isotopes was examined in the biological material, which characterized the frequency of visits to the sources. It was found that frugivorous bats visited mineral sources much more often than omnivores, but only during pregnancy and feeding their young. At the same time, the mineral content in the tissues of expectant mothers was more than enough to keep themselves in shape and raise their offspring. This did not stop them from drinking water rich in salts and eating rich mud, which, among other things, well compensated for the effect of plant toxins - alkaloids, glycosides and various acids, which ripe fruits contain in excess. However, if poisons have practically no effect on an adult, then the situation with cubs is different. Therefore, during pregnancy and lactation, bats more intensively cleanse their bodies of toxins in order to protect their offspring.
Movement
The main method of movement of bats is flapping flight. However, some biospecies are capable of running briskly on all fours, leaning on the folds of their wings, swimming and taking off from the water.
Landing upside down
All types of bats use the tactic of landing upside down. According to Dr. Daniel K. Riskin from Brown University (Providence, USA), such techniques first appeared in bats 50 million years ago.
Completing a flight involves a special risk - you need to slow down, but not fall. Birds do this with their wings, but bats complete their flight by performing special maneuvers called four-touch and two-touch tactics. To land safely upside down, they have to perform complex acrobatic tricks. In addition, adaptation to flight creates additional difficulties when landing: bats have the lightest and most fragile bones of all mammals - to reduce body weight and shift the center of gravity. As a result, the limbs experience high impact loads and can be damaged. Therefore, during the course of evolution, bats began to minimize the load on their bones when landing and learned various acrobatics. Different species of bats use different tactics.
This aspect was studied by a team of chiropterologists led by Dr. Daniel Riskin. To conduct the experiment, captive-bred bats of the Malayan short-nosed fruit bat species were taken ( Cynopterus brachyotis), spectacled leaf-nosed plant ( Carollia perspicillata) and shrew-like long-tongued vampire ( Glossophaga soricina), provided by one of the laboratories at Harvard University. Scientists constructed a special enclosed room, placing a grid on the ceiling on which bats could land. Then the experimental animals were launched there one by one, and their flights and landings were recorded by a high-speed camera.
The "four-touch" tactic has been recorded in the Malayan short-nosed fruit bat. The chiropters flew up to the ceiling with their wings spread. As soon as contact with the ceiling occurred, the limbs extended, and the animals grabbed the grate with the thumbs of the forelimbs at the same time as the fingers of the hind limbs. Then they somersaulted backwards over their heads and hung upside down. With such a landing, the fruit bat experiences fourfold overload. Sometimes, during such a landing, bats even hit their heads on the ceiling. Biospecies that use such tactics often land on trees because they feed on plant foods. This environment itself is not as rigid as the stone walls of a cave.
The “two-touch” tactic is used by the spectacled leaf-nose and the shrew-like long-tongued vampire. They flew up perpendicular to the surface of the grid, but at the very last moment they deviated to the right or left. And then they grabbed the bars, but only with the fingers of their hind limbs. This landing is much smoother, and the overload upon impact is only one third of the animal’s body weight. The tactic is used by insectivorous bats and vampires that land on the stone walls of caves. According to Daniel Riskin, such bats have an evolutionary advantage because they experience much less impact force when landing.
Reproduction
When courting, males sing individual songs, combining syllables in different variations. The Brazilian folded lip has a call of 15 to 20 syllables.
The sexual activity of most species has not been studied due to the difficulty of observation. Chiropterans breed mainly in hard-to-reach places, such as deep caves, cracks or tree hollows. Therefore, data exists for less than 0.9% of biospecies.
Most often, the female gives birth to only one, naked and blind cub, which she feeds with milk. Sometimes, while the cub is still small, it flies with its mother to hunt, tightly clinging to her fur. However, this method soon becomes inaccessible to them, because the cubs grow quickly. Then the mother leaves him hanging in the shelter and, after hunting, finds him among many strangers, using echolocation, position and smell.
Ecology of bats
Bats play an important role in ecosystems, as they consume large quantities of insects that harm agriculture and forestry and carry pathogens of dangerous diseases (malaria, leishmaniasis, etc.).
Frugivorous species facilitate seed dispersal. The fruits on the corresponding trees are located away from the main crown and protective thorns, which makes it easier for bats to access them. The fruits also have a rotten, sour or musky odor and contain one large or several small seeds. The animals eat only the pulp and throw out the seeds, thereby helping the woody species spread. Nectarivorous species, accordingly, pollinate plants whose flowers are specially adapted to bats.
But bats themselves are also carriers of viruses dangerous to humans, including rabies. Recently, the phenomenon of the formation of local foci of radioactive contamination of the area was described for the first time in the Urals for some species (pond bats and northern leopards).
In sparsely forested areas of the center of the European part of the USSR, the extermination of forest pests by bats accelerated its growth by 10%.
Migrations
Bats make long flights to wintering grounds, sometimes in general mixed flocks together with insectivorous birds. In temperate latitudes, bats make seasonal migrations.
Long-distance flights of bats are mentioned in zoological literature of the 19th century.
Species threat and conservation
Chiropterans are often destroyed by ignorant people, teenagers and children who have no idea about the significance of the animals. Windmills pose a danger to bats because they cause barotrauma when they enter an area of low pressure at the end of the blades.
The organization of the protection of bats is facilitated by information about the places of their aggregations, cases of mass death, encounters with ringed animals, mass seasonal migration, and the like.
At the first All-Union meeting on bats in 1974 in Leningrad, it was recognized that it was necessary to actively promote the importance and protection of bats among the general population using all media for this purpose.
Chiropterans and humans
Chiropterans, primarily bats, have had a bad reputation in Europe for a long time. They are depicted as a classic retinue for witches and wizards.
Fruit-eating bats can cause significant damage to gardens.
In South America, the ancient Incas used bat fur to decorate clothing, which only members of the royal family had the right to wear. In East Asia, Oceania and Africa, chiropteran meat is consumed as food.
Chiroptera research
Chiropterans began to attract the attention of scientists at the beginning of the 20th century. In the 70-80s, three all-Union meetings on bats were held in the USSR, where the features of echolocation of bats, the most complex biochemical processes in the central nervous system of bats, measures to improve the protection of bats, classification issues, etc. were discussed.
There was also a debate about the name "bats". Some experts showed its incorrectness, citing the lack of relationship between bats and rodents. Previously, the term "bats" referred to the entire order rather than a suborder; The Soviet Committee on Zoological Nomenclature decided that, in order to avoid confusion, the order should retain its old name - “chiroptera”.
To study bats from wild populations, scientists visit their dens, which can be very dirty and smelly, in order to catch the desired individuals. The bright beam of the lantern frightens the animals hanging on the vault, which is why they take off in large numbers and rush around the cave. Such a sight can confuse not only a beginner, but also an experienced chiropterologist.
Nectarivorous bats can thrive when kept in enclosures. They are fed with a composition slightly different from artificial food for hummingbirds: condensed milk diluted in water to the consistency of regular milk, with the addition of powdered biologically active food additives corresponding to the biospecies. The composition is poured into a beaker and attached to the wall, from where the animals drink it.
Captured insectivores must feed by hand for the first few days and only then begin to eat mealworms on their own.
Classification
Chiropterans are divided into two suborders: fruit bats (one family) and bats (17 families). It has previously been suggested that these groups evolved independently and their similarities are convergent, but recent genetic studies suggest that they shared a common flying ancestor. Consequently, their unification into one detachment is natural.
Currently, about 1,300 species of bats are known (about a fifth of all mammals).
The order Chiroptera was formerly grouped together with the Wooloptera, Tupaiformes and Primates into a superorder Archonta. According to modern views, bats belong to the superorder group Laurasiatheria, considering it as part of the clade Ferungulata (Cetartiodactyla + Ferae + Pholidota + Perissodactyla), or as sister to it. Below is a diagram of the relationships between the Laurasiotherium orders according to Nishihara et al. (2006), but the reliability of this particular branching order is low.
| Laurasiotherium / Laurasiatheria |
|
||||||||||||||||||||||||
Currently, the taxonomy of bats is as follows:
Suborder YINPTEROCHIROPTERA
- Infraorder fruit bats (flying dogs or flying foxes) Megachiroptera
- Fruit bats ( Pteropodidae)
- Infrasquad, Yinochiroptera
- Superfamily Rhinolophoidea
- Mousetails (lancetails) ( Rhinopomatidae)
- Pig-nosed ( Craseonycteridae)
- Horseshoe-nosed animals ( Rhinolophidae)
- Old World Leaf-noses (Horseshoe-lipped) ( Hipposideridae)
- Tridentate ( Rhinonycteridae)
- False vampires ( Megadermatidae)
- Superfamily Rhinolophoidea
Suborder YANGOCHIROPTERA
A high rate of evolution is sometimes cited as a progressive characteristic of a group, often primates, but this position needs categorical clarification.
Teniodonts. Top - skulls: top row (from left to right) - Onychodectes, Wortmania, Ectoganus;
middle row - Psittacotherium, Stylinodon;
bottom - Onychodectes, Stylinodon
On the successive series of Paleocene taeniodont Taeniodonta one can see how from a creature similar to insectivores and opossums - Onychodectes– through a dog-like beast – Wortmania- a strange monster may develop like Psittacotherium, Ectoganus or Stylinodon the size of a bear. Probably, among Paleocene animals, taeniodonts had the maximum rate of evolution. However, no one considered them as particularly progressive mammals.
Teniodonts can serve as a clear example of how one can quickly specialize and lose the opportunity to become a “true primate.”
Another example of rapid specialization is found in Chiroptera bats. Chiropterans were probably already present in the Upper Cretaceous of South America and the Upper Paleocene of France and Germany (Gingerich, 1987; Hand et al. 1994; Hooker, 1996), and unambiguous representatives of the Lower Eocene are hardly distinguishable from modern ones, and were found in dozens of species at once. all continents, including Australia.
It is remarkable that the teeth of Lower Eocene bats are almost identical to the teeth of primitive placental type Cimolestes and the oldest shrews, so the relationship of all these groups is beyond doubt, which is clearly confirmed by genetic data. Despite the fact that in genetic-cladistic schemes chiropterans fall into the Laurasiatheria Laurasiatheria, and primates into the euarchontoglires Euarchontoglires, the similarity of these two groups has always been obvious to all taxonomists, starting with C. Linnaeus, and was reflected in the creation of the “archon” group Archonta, uniting bats, primates, tupayas and woolly wings. The similarity of the ancestors of the representatives of the “archon” was enhanced by the arboreal lifestyle of the ancestors of bats and woolly wings and, at a minimum, by pre-adaptation to it in the ancestors of primates and tupayas. Obviously, the reason why it is not possible to identify the immediate Lower Paleocene or Cretaceous ancestors of bats is that their teeth are indistinguishable from the teeth of other primitive animals. It is possible that some Paleocene forms, known only from teeth and now considered primates, plesiadapis, or some insectivores in the broad sense, will turn out to be primitive bats with better study. Until bats had wings and echolocation, we consider them "insectivores", when did these specializations appear (judging by Onychonycterisfinneyi, flight arose before echolocation (Simmons et al., 2008)), we already see ready-made chiropterans.
As in the case of birds and pterosaurs, the flapping flight of bats arose very quickly, and it is extremely difficult to catch the moment of its formation, for this you need to have incredible luck.
Chiropterans are unique in the sense that the first stages of their evolution were distinguished by maximum rates, and the subsequent ones by extremely low rates (or rather, at the level of species and genus formation the rates were high, but the structural plan even at the family level has practically not changed since the Lower Eocene); one could even argue that macroevolution in bats ended at the same time that it was just beginning in primates. Obviously, the reason for this was adaptation to flight. The already poor reserves of the brain structure of the first ancestors were hopelessly suppressed by the need to lighten the weight; this is clearly expressed in the rapid overgrowth of the sutures of the skull, which was already characteristic of the early Eocene Icaronycterys. We are also not talking about the grasping ability of the limbs, but rather about the grasping ability; Lower Eocene Onychonycteris had claws on all fingers of the wing, and the rest of the synchronous relatives had already lost two or three.
True, bats have two significant advantages over insectivores: they live a long time, and therefore can accumulate rich life experience, and are very sociable - even taking care of hungry relatives among vampires Desmodus rotundus. But these advantages are negated by the small size of the brain - an expensive price to pay for conquering the heavens. Surprisingly, over tens of millions of years, not a single bat has lost the ability to fly or returned to a terrestrial or arboreal lifestyle (in the fantastic fauna of the future, the inventive mind of D. Dixon dreamed of predatory land vampires, walking on their front legs and grabbing prey with their hind legs, but this infernal image, fortunately, remains purely hypothetical and remains on the conscience of its creator).
At one time, the so-called “flying primate” hypothesis caused a lot of noise, according to which megachiroptera Megachiroptera - fruit bats - acquired the ability to fly independently of other bats - microchiroptera Microchiroptera, and, moreover, arose from the most ancient primates (Pettigrew, 1986; Pettigrew et al ., 1989; Pettigrew et al., 2008). Many arguments were given as proof, the main of which was the specific type of neural connection of the retina with the superior colliculi of the quadrigeminal in the midbrain - unique for primates, woolly winged winged bats and fruit bats, as well as the absence of echolocation in the vast majority of the latter, in contrast to small echolocating bats. Other evidence of the independent emergence of macro- and microchiroptera has been provided.
At a certain point, the concept of “flying primates” almost took over, but immediately suffered a crushing defeat from geneticists, who quite convincingly proved the monophyly of chiropterans (Mindell et al., 1991);
Attempts have been made to challenge these genetic results (Hutcheon et al., 1998), but they are not accepted by most taxonomists. However, the recognition of the common origin of bats cannot reject the many amazing parallels between fruit bats and primates. Even if these similarities evolved convergently, they are too complex to be entirely coincidental; yet this situation is a reflection of the extreme closeness of the ancestors of both orders. There are no fossil forms that would “hang” between bats and primates (the African early Miocene fruit bat is described Propottoleakeyi, whose name speaks for itself (Simpson, 1967; Walker, 1967), but this is a matter of confusion, not intermediateness) - this is a consequence of the rapid specialization of the former.
Much thought has been spent on clarifying the question of whether the ancestors of bats were insectivores or frugivores. The teeth of the oldest known forms are “insectivorous,” but the Paleocene could well have been distinguished by a greater love for the works of flora. The ongoing debate on this issue, as well as the existence of both types of nutrition among modern bats, is further confirmation of the fragility of the line between these two diets, no matter how different they may seem.
In general, the sequence of specializations of chiropterans seems to be something like this: judging by the most primitive bat Onychonycteris, which did not have developed echolocation (although there is another opinion that it could have had “laryngeal echolocation” (Veselka et al., 2010)) and fed on insects; echolocation arose later than flight, and the first diet was insects; other synchronous bats are also insectivores, but echolocating. Judging by the absence of echolocation in most frugivorous fruit bats and its presence in some representatives of the same group (Egyptian flying dog Rousettusaegyptiacus echolocates by clicking the tongue), as well as its preservation in frugivorous and nectarivorous microchiropterans, echolocation could disappear in frugivorous forms, but not necessarily; echolocation and insectivory are found in the horseshoe-labiates Hipposideridae, horseshoe bats Rhinolophidae, pseudo-vampire Megadermatidae, pig-nosed Craseonycteridae and mouse-tailed Rhinopomatidae, which are genetically close to fruit bats; on the other hand, insectivores repeatedly and independently switched to frugivory. On the other hand, all modern insectivorous forms have developed echolocation. Judging by the development of a complicated nerve connection between the retina and the quadrigemina specifically in non-echolocating fruit bats and the primitive variant in all other bats, the “primate” version of the nervous system arose in fruit bats independently. All these subtleties seem extraneous to the problem of the origin of primates, but in fact they are directly related to it.
After all, common ancestors imply that primates also had a chance to develop similar adaptations.
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