Number of insectivorous mammals. Representatives and characteristics of the order insectivores. Brief description of the squad

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 flight 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 cub (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.

1) Systematic affiliation: toclass Mammals; infraclass higher animals; superorder insectivores

2) Features of the external structure: the limbs are not located along the sides of the body, like in reptiles, but under the body, so the animal’s belly does not touch the ground. They walk relying on their fingers, with strong claws. Of all animals, only mammals have an external ear - the auricle.

The skin of mammals is strong and elastic; in most animals, the bases of the hairs, which form the scalp, are located in it. There are thick and long hairs - the awn and shorter, soft ones - the underfur, or undercoat. A rough and strong awn protects the undercoat from damage to the skin; the undercoat, which retains a lot of air, retains body heat well. In addition to the awn and underfur, animals develop large hair - organs of touch.

3) Features of the internal structure: the respiratory system of mammals is very perfect. It ensures intense gas exchange, which is one of the prerequisites for a high, constant body temperature. The lungs of mammals consist of two spongy sacs in which the airways, the bronchi, branch complexly. The latter end in a huge number of thin-walled vesicles (alveoli), entwined with blood capillaries. Gas exchange occurs in the walls of the alveoli, during which the blood releases the carbon dioxide it contains and is enriched with oxygen. Respiratory movements caused by contraction of the chest and diaphragm are quite slow in large animals (about 10 per minute), while in small animals they are very intense (up to 200 per minute), varying depending on the temperature of the environment and the body of the animal. Changing the frequency of respiratory movements is one of the means of regulating body temperature when overheated. Closed circulatory system. The circulatory system ensures a high intensity of blood flow, a high level of metabolism and the maintenance of a stable body temperature. The heart is four-chambered; there is only one - the left - aortic arch, extending from the left ventricle. After passing through the system of arteries through the systemic circulation, the blood returns to the heart through two large anterior vena cava and a single posterior vena cava, which flows into the right atrium. From the right ventricle, venous blood is sent through the pulmonary artery to the lungs. After oxidation in the lungs, arterial blood returns through the two pulmonary veins, which drain into the left atrium. The excretory organs of mammals are a pair of bean-shaped kidneys located in the abdominal cavity on the sides of the lumbar girdles. The resulting urine enters the bladder through two ureters, and from there it is periodically discharged through the urethra.

4) Peculiarities of reproduction: the reproductive organs of the male are paired testes with ducts, but they are carried out of the body cavity into the external genitalia, and the ducts open in the copulatory part of this organ. The reproductive organs of the female, compared to those of a reptile, are greatly changed; they consist of paired ovaries and two oviducts, which at some distance from the ovaries merged, forming a muscular sac - the uterus, and below it they form a vagina, which opens outward.

5) Exceptional features: all mammals feed cubs with milk. Milk contains all the substances necessary for the development of the body and is easily digestible. Insectivores have well-developed jaws and muscles for chewing. The main food of insectivores, according to the name, is insects, centipedes and worms . A feature common to all insectivores is a movable muzzle elongated into a proboscis, which indicates an excellent sense of smell. But judging by the small size of the ears and eyes, these animals are no different in hearing and vision. However, they can emit and perceive ultrasound and, possibly, use echolocation to navigate in space.yu, like bats.

The amazing world of nature amazes with its diversity and beauty. Some of the most interesting animals are insectivores. To expand your knowledge of biology, you need to study these animals. A detailed description of insectivorous animals will help you learn about their characteristics.

Who are insectivores

These include one of the most ancient groups of animals. Their remains were found by scientists in the deep layers of the Mesozoic era. The oldest of them is about 135 million years old. Representatives of this family include: moles, shrews, hedgehogs, muskrats, and several species of birds. They live on the ground, in fresh water reservoirs, forests, and also in the soil. Among the winged insectivores are: finches, orioles, warblers, and cuckoos.

The hedgehog is considered the most primitive and resistant to external changes. The shrew and mole were almost the same as hedgehogs, but at the end of the Eocene era they had to adapt to new living conditions. Evolution has subjected these animals to external changes.

Signs of the insectivorous family

It is quite easy to identify its representative. The head of these animals is slightly elongated and always ends with a small proboscis, which reacts sharply to any odors. Some animals have no visible eyes, as they are hidden under folds of skin. The most active sense organs are smell and touch. They help the animals obtain insect larvae from the most inaccessible places.

The number of teeth varies from 26 to 44. In the spaces between the molars there are sharp ridges that form the letter W or V. It is this type of dentition that is considered a special feature of insectivorous animals. The body shape of animals largely depends on their lifestyle. The limbs always have feet and fingers with claws. The fur on the skin is also quite different, differing in thickness and softness. Some types of insectivorous animals wear spines on their bodies. The color of the animals is mainly monochrome, with gray, black, brown and brown colors predominating.

Where do insectivores live?

They live everywhere, excluding Antarctica, Australia, and some areas of South America. These animals can be found right up to the very closest environs of the Arctic Ocean. Animals have a nocturnal, aboveground, underground or underwater lifestyle. Insectivorous birds live in trees and bushes. In almost every city and town you can see starlings, finches, thrushes and hoopoes. Nests of cuckoos, warblers, and kinglets often appear on old trees. The number of sparrows and titmice also seems to increase every year - these little feathered friends are regular guests of any park or city street.

Characteristics of the hedgehog family

The order contains a large number of insectivorous animals. The most common are common and long-eared hedgehogs. Each of these species has 5 varieties. The animals are distinguished by medium shapes. The body length of an ordinary hedgehog ranges from 13 to 27 cm. The entire back is covered with thin but sharp spines, which are also found on the sides of the animal. Long and sparse hair grows between the needles. There are no needles on the hedgehog's abdomen - it is completely covered with coarse hairs.

The head of hedgehogs is oblong, slightly wedge-shaped. The muzzle is elongated and has a thin, movable nose that resembles a trunk. The color of hedgehogs is always gray or brown, with black or brown spots. Nature ordered that these animals blend in color with the earth as much as possible. This makes it easier for them to move around and collect food without being seen by predators.

The smallest insectivorous animals are shrews

Another species of mammal that prefers to eat insect and worm larvae. Due to their modest size, they have extraordinary agility and speed. Like many insectivorous animals, shrews do not like sunlight, dryness and heat. They live in different areas. They can always be found in the forest, among dense bushes, in meadows and fields. They are also permanent residents of any vegetable garden or garden. From there they try to eradicate them in every possible way, since these animals can spoil the beautiful appearance of home flower beds.

Being unusually voracious, they eat constantly. Shrews' favorite food is insects and worms. These animals lead an active life throughout the year. In winter, they dig tunnels under the snow, looking for insects that have gone into hibernation. By eating pests, shrews help humans and save plants from destruction.

Endangered species of insectivore - muskrat

This species of animal is listed in the Red Book and is carefully protected in protected areas and zoos. This happens due to the fact that the number of muskrats is decreasing very quickly. If we do not take care of them, the planet may lose these useful forest orderlies.

In appearance, we can say that the muskrat is very similar to the shrew, but is several times larger. The animal lives on rivers and leads a semi-aquatic existence. It can not be found in every area. This species prefers rivers belonging to the Dnieper, Don, Ural and Volga basins. The muskrat's tail is quite long, slightly compressed at the sides, and its limbs are equipped with membranes for rapid movement under water. The fur of these animals is surprisingly soft, thick and silky. Has water-repellent properties. The muskrat lives in burrows, which it likes to create in floodplains. They usually only have one outlet underwater.

Underground inhabitants - moles

These animals are also among the most common insectivores. Moles live in underground burrows. For housing, they choose forest or rural areas with water currents. Moles dig a hole for themselves with their front paws. Their wide and everted hands can dig a deep tunnel in the shortest possible time. They push out excess soil with their muzzle, creating vertical passages at the top. Such slides on the surface are called molehills. They are a sign that a mole has settled nearby.

Insectivorous animals (moles, in particular) have very poorly developed eyes. From the outside, they only resemble small black dots. Moles also do not have ears. The ear is covered with a fold of skin to prevent soil from getting into it. The coat is very thick and short. For convenient movement underground, it is deprived of one direction. The fur fits tightly to the mole's skin and therefore does not interfere with its movement in different directions.

Long-term observation of insectivorous mammals has made it possible to identify many interesting facts regarding their life and living conditions. Among the most unusual and surprising are the following:

Interesting facts about insectivorous animals allow you to learn a lot about them. Every type of animal deserves to be treated with care. They cleanse the soil and plants of pests. That is why they need care and protection.

The order of insectivores includes small and small placentals. In most of them, the anterior section of the muzzle is elongated into a movable proboscis, the body is covered with hair, and in some, with bristles or needles. Many species have developed scent glands. Their internal organization is relatively primitive: the braincase is quite small, the cerebral hemispheres are small and lack convolutions, the teeth are poorly differentiated, and the fangs rarely have a typical shape and size. Insectivores are considered the most ancient of the placentals.

Insectivores are widespread throughout the globe, although they are absent from Australia and much of South America.

Representative: common hedgehog

Muskrat a small animal with a long tail, which is laterally compressed and covered with large horny scales. There are swimming membranes between the fingers. The fur is very thick and silky. The muskrat leads a semi-aquatic lifestyle. At the beginning of the twentieth century, the muskrat was almost completely exterminated due to its valuable fur and musk glands, and currently this animal is under protection.

Moles- small animals adapted to an underground lifestyle. Their body is ridged, their head is cone-shaped, their muzzle is elongated into a proboscis, they have no ears, their forelimbs are short, but their claws are large, their fur is short, soft, and velvety. The olfactory organs are well developed, and the eyes are rudimentary. They shed difficultly, 3 times a year.

Representatives: common mole, Siberian mole.

Shrews- small and very small animals, externally similar to mice, from which they differ in their muzzle elongated into a proboscis. Their tail is quite long and their limbs are short.

Representatives: baby shrew, little shrew (the smallest mammals). The body is about 4 cm, weight is 1.5-2.5 g. During the day they eat 3-4.5 times their weight in food. They can fast no more than 5-6 hours a day.

Representatives: tiny shrew, small shrew, common shrew, water shrew.

Order Chiroptera

Small and medium-sized mammals adapted for movement in the air are combined. Their wings are made up of leathery membranes stretched between the long fingers of the forelimbs, the sides of the body, the hind limbs and the tail. Only the first finger of the forelimbs is free and does not participate in the formation of the wing. The sternum, like that of birds, has a keel to which the pectoral muscles are attached, which move the wings.

Chiropterans are active at dusk and at night. On the ground they are usually helpless, but in the air they are fast and agile. Vision is poorly developed, but most people have exceptionally fine hearing. The range is huge from 12 to 190 thousand Hz (a person perceives sounds from 40 to 20 thousand Hz). They navigate in space using sound location. Before the flight, ultrasounds are emitted with a frequency of 30-70 thousand Hz. Ultrasounds reflected from obstacles are perceived by the hearing organs, which allows the animal to recognize the situation in front of it and catch flying insects. They feed on a variety of foods and can even drink the blood of vertebrates. Many people can eat an amount of food equal to their own body weight per day.

Bats– small, have sharp teeth and relatively large ears. They live in colonies or alone. Active at dusk. Developed sound location.

Bats that feed on blood have a pain-relieving substance in their saliva, as well as a substance that prevents blood clotting.

In winter, they hibernate (anabiosis) or fly to the southern regions, where they accumulate in huge quantities.

Representatives: leather bats, bats, noctules, longwings, eared bats.

Fruit bats– small and medium-sized bats. Fruit bats have a keen sense of smell, acute vision, and are almost incapable of sound signaling.

Representatives: flying dog, or kalong.

Squad of rodents

Includes small and medium-sized mammals that consume mainly plant food. Their appearance is varied, but the dental system in all species is adapted to gnawing and chewing solid plant food.

In the upper and lower jaws sits one pair of large chisel-shaped, rootless and constantly growing incisors. The front wall of the incisors is covered with enamel and is strong, while the back wall is devoid of enamel and is soft. Due to uneven grinding, the tips of the incisors are always sharp. They are partially exposed, since the upper lip is often deeply split. Molars have a wide chewing surface on which there are tubercles. There are no fangs, so between the incisors and molars there is a wide toothless gap - a diastema. Due to the diet of coarse plant foods, the intestinal tract is long. All species have a cecum, which is a kind of “fermentation vat.” Rodents are distinguished by early puberty and numerous offspring. There are terrestrial, underground, arboreal and semi-aquatic forms.

Squirrel- live in hollows in trees. It does not hibernate during the winter. It feeds more often on coniferous seeds, less often on berries and mushrooms.

Chipmunks– have a striped color and a relatively fluffy tail. They lead a terrestrial lifestyle, living in burrows. They hibernate for the winter, but make reserves in the fall.

Gophers And marmots live on earth. Distributed in steppe and mountainous regions. They live in burrows, feed on grass and seeds, and usually live in colonies. They can carry dangerous diseases (plague, tularemia).

Representatives: small gopher, speckled gopher, yellow gopher, bobak.

Beavers– was almost universally exterminated in the last century, but its numbers have now increased. Beavers live in colonies along forest streams. Their homes are huts and holes made from branches. In places of settlement, beavers build dams that raise the water level in the river.

Porcupines- the largest animals among rodents. Length 70-90 cm, and weight up to 30 kg. They are active mainly at night. During the day they hide in a shelter.

Mouse- the largest group of rodents. Most of them are small animals. They live in burrows, feed on plant foods and sometimes insects. They are distinguished by early puberty and very high fertility.

Representatives: house mouse, field mouse, forest mouse, gray rat, or pasyuk.

Muskrat- a large rodent with valuable fur, its homeland is North America. Leads a semi-aquatic lifestyle, lives in thickets of reservoirs, where it settles in huts and burrows. Feeds on aquatic vegetation. It multiplies very quickly. They become sexually mature at less than a year old. One of the most important fur-bearing animals.

Other representatives mouse: Dormouses, jerboas, mole rats, nutria, chinchilla, guinea pigs(domesticated forms).

Insectivores are small placental mammals. Body length ranges from 3.5 cm (the smallest size in the class of mammals) in the dwarf shrew and up to 44 cm in the large rat hedgehog. The muzzle is elongated, usually ending in a small proboscis. The external ears are small and may be absent in some representatives. The eyes are small, sometimes at varying degrees of reduction. The limbs are four- or five-fingered, plantigrade, all fingers are armed with claws. The hairline is usually short, soft, poorly differentiated; sometimes the body is covered with spines. The skin contains sebaceous, primitive sweat and specific glands. Nipples from 2 to 12.

Insectivores are characterized by a number of features due to which they should be considered more primitive than other placental mammals: small size, plantigrade limbs, underdeveloped auditory drums.

They lead a terrestrial, underground, semi-aquatic or arboreal lifestyle. Most of them are active at night; Some have 24/7. They feed mainly on insects, although there are also predators among them. Insectivores are polygamous. Pregnancy 11-43 days. There is usually one litter per year, rarely more. There are up to 14 cubs in a litter. Sexual maturity is reached at the age of 3-4 months to two years. The economic importance is relatively small. A number of species benefit forestry and agriculture by eating harmful insects. Some species (mole) are of commercial importance.

Distributed throughout the world, with the exception of Australia, most of South America, Greenland and Antarctica. Insectivores are the most ancient and primitive among placental mammals. The ancestors of modern insectivores were, apparently, the ancestors of all other placental mammals. Among modern families of insectivores, most of which have been deeply adapted to specific living conditions and, in connection with this, have undergone significant changes, the most primitive is the family of hedgehogs. Shrews and moles probably diverged from hedgehog-like ancestors around the end of the Eocene or the beginning of the Oligocene. Findings of fossil remains of other modern families date back to the Miocene (tenrecs, golden moles and jumpers) or Oligocene (snaptooths).

Chiroptera (lat. Chiroptera) is an order of placental mammals, the only one whose representatives are capable of active flight. This is the second largest (after rodents) order of mammals, including 1200 species. The science of chiropterology is devoted to their study. Systematically, bats are close to insectivores.

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 extend to the northern border of the taiga (representatives of the family common bats, in the southern part of the USA and the Mediterranean species There are already several dozen, and in the Congo and Amazon valleys - several hundred species. The reason for such a sharp increase in the number of species is the high density of bats in the tropics and the resulting aggravation of their competitive relationships.

Chiropterans are extremely diverse; they inhabit all continents of the Earth, with the exception of Antarctica, and make up 1/5 of the total number of living mammal species. Their primary mode of locomotion is flapping flight, a feature that allows them to take advantage of resources not available to other mammals.

The sizes of chiropterans are small and medium: 2.5-40 cm. The forelimbs are transformed into wings, but in a significantly different way than in birds. All fingers of the “hands”, except the first, are greatly elongated in chiropterans 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 chiropterans, 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. 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 weak and is of little importance for orientation. Hearing is extremely subtle. The hearing range is huge, ranging from 12 to 190,000 Hertz.

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.

Many bats are nocturnal or crepuscular animals. Some species hibernate in winter, others migrate.

Oral sex has been recorded in short-nosed fruit bats. 70% of the females observed during the experiment licked their partner's penis before copulation, which led to approximately doubling the time of sexual intercourse.

Most often, the female gives birth to only one, naked and blind cub. Sometimes, while the cub is still small, he flies with his mother to hunt, tightly clinging to her fur. However, this method soon becomes inaccessible to them, because the cubs grow quickly.