Who belongs to insectivorous animals. Interesting fact about mammals. Interesting facts about carnivorous mammals, insectivores. What do insectivores eat?

Squad Insectivores

This order includes hedgehogs, moles, shrews. These are small animals with a small brain, the hemispheres of which do not have grooves and convolutions. The teeth are poorly differentiated. Most insectivores have an elongated muzzle with a small proboscis. They feed on small invertebrates, mainly insects. They are widespread on our planet, found everywhere except Antarctica, Australia and most South America.

Of the hedgehogs in our country, the common hedgehog is the most widespread. It is often found on the edges of deciduous and mixed forests, overgrown with shrubs, often in the forest-steppe, willingly inhabits orchards. It is active at dusk and at night (see the figure of the textbook, p. 230).

Common hedgehog

Common hedgehog- insectivorous, with a body length of 20–30 cm, weight 700–800 g. The body is heavy, short legs, the back is covered with sharp needles. The entire belly and head are covered with brownish wool. Special muscles allow the hedgehog to curl up into a ball and lift the needles. In this position, he is almost invulnerable. However, he also has enemies. So, during a night hunt, an owl attacks him, which is not afraid of the hedgehog's needles, since his fingers are covered with strong horny scales.

It is not always possible for the hedgehog to escape from the fox, which carefully rolls it up to the nearest body of water. Once in the water, the hedgehog unfolds and becomes a victim of the fox.

The hedgehog feeds on various small animals: earthworms, insects and their larvae, slugs, frogs, mice. Sometimes he attacks the viper, as he is insensitive to the action of its poison.

In the second half of summer, in the forest under a bush or in a deepening of the soil, you can find a hedgehog nest with 4–8 cubs. Hedgehogs are born with closed eyes and ears, they are covered with light soft spines. The hedgehog feeds the cubs with milk, in case of danger, transfers them to a new nest. The hedgehogs grow quickly and after two months they reach the size of adults, and the next year they become sexually mature.

In the fall, the hedgehog begins to set up a winter den, which he makes in a heap of straw, leaves, moss. The material collects in a peculiar way: it rolls around in fallen leaves, stringing them on needles. Hibernates in September - November.

The common hedgehog benefits forestry and agriculture, as it destroys the mass of murine rodents and harmful insects.

Common mole

Common mole - a small animal, its body length is 12–16 cm, weight is 60–110 g. It lives on forest edges, meadows, fields, river floodplains, prefers soil rich in earthworms and other invertebrates. Leads an underground lifestyle. In this regard, it has a number of adaptations: the body is rolling with a pointed head, covered with thick velvety fur. The hair does not have a definite direction, due to which the mole moves freely along narrow earthen passages both forward and backward. The shortened front legs with wide five-fingered palms-shovels are turned outward. Moles use them to make underground passages. Caught by surprise at the surface of the earth, the mole instantly disappears into the depths of the soil. The mole's head also serves to throw the earth out, resulting in the formation of "mole heaps" - molehills, which reveal its location. The mole is active throughout the year, for the winter it leaves for food (worms, insect larvae) into deeper layers of the soil.

In one of the deep passages, the mole makes a nest, in which the female gives birth to 3 to 7 naked blind cubs in summer. For about a month, the mother feeds them with milk, the cubs grow and develop quickly. Sexual maturity is reached the next year (see the picture of the textbook, p. 230).

The mole has few enemies, it is a fox and a marten, as well as frosty winters with little snow, from which many of them die.

The mole brings certain benefits, destroying many harmful insects and their larvae, changing the structure of the soil. In addition, the mole is a valuable fur animal.

The order of insectivores includes shrews(common shrew, water cooler, etc.). Outwardly, they are very similar to mice, but differ from them in a pointed muzzle, elongated into a proboscis, small ears and eyes hidden in soft velvety wool.

Common shrew

Common shrew- a small animal, body length 6–9 cm, tail - 3.5–5 cm, weight from 8 to 15 g. Its velvety fur is dark brown or brown above, and lighter below; in winter, its color is darker. Lives in coniferous, deciduous and mixed forests, preferring wet areas. It is often found in the floodplains of forest rivers, streams and forest ravines. The animal is very careful and spends most of its time in the passages under the forest litter or surface layers of the soil, looking for food: insects, earthworms, slugs. Often the shrew attacks mice or frogs. She also consumes small amounts of plant foods (spruce seeds, cedar, berries, etc.). The activity is round-the-clock (throughout the year), most of the time it hunts, since it cannot "fast" for more than nine hours, otherwise it dies. The shrew reproduces throughout the warm period of the year, during which time the female twice brings from 4 to 10 cubs, which grow and develop rapidly.

The shrew is a useful animal for forestry, as it destroys a lot of harmful insects and their larvae, as well as murine rodents (see the figure of the textbook, p. 230).

Water cooler

Water cooler- a large shrew, body length 7–10 cm, tail 6–7.5 cm, weight 10–17 g. Hair color is bicolor: the back is brown-black, and the belly is silvery-white, the tail is bicolor (see fig. of the textbook , p. 230).

Kutora lives in the forest near rivers, lakes, in swamps. Leads a semi-aquatic lifestyle, swims well, dives well. She is well adapted to this lifestyle. Its thick fur does not allow water to pass at all, leaving the water, the animal remains dry. Fingers hind legs bordered by a comb of dense hair, straightening in the water, they turn the hind legs into oars. The ears are able to close when diving. Despite its small size, kutora - dangerous predator: It feeds on insects, molluscs, frogs, mouse-like rodents, which it hunts at dusk and at night. She runs well on land, putting her long muzzle up and moving it from side to side. Sometimes the kutora makes food reserves, dragging caught insects, worms and other small animals into the soil. During the summer, it twice brings offspring to the holes prepared for this, in which the cubs stay for the first time after birth.

Kutora destroys many harmful invertebrates, but also destroys fish fry and eggs, causing damage to the fish industry.

From the book Animal Life Volume I Mammals the author Bram Alfred Edmund

Order VI Insectivores (Insetivora) The order of insectivores includes small animals with an elongated head and an elongated muzzle, like a trunk, covered with soft, silky wool, or spiky needles. They are found mainly in the temperate countries of the northern

From the book Animal World. Volume 1 [Tales of the platypus, echidna, kangaroo, hedgehogs, wolves, foxes, bears, leopards, rhinos, hippos, gazelles and many others the author Akimushkin Igor Ivanovich

INSECTS p. 247, Box 1 Insectivores vary greatly in size, from 3–5 to 3–50 cm, and weight, from 1.5 g to 1.5–2.0 kg. 247, Box 2 Insectivores do not shine with mental abilities, but, like all living things, they are perfectly adapted to their habitat. Some

From the book Animal world of Dagestan the author Shakhmardanov Ziyaudin Abdulganievich

SQUAD WANTED p. 285, Box 18 Now - Elephas maximus and Loxodonta africana P. 285, Box 19 The trunk is not an extension of the nose, but the upper lip fused with the nose. It is interesting that in zoos an elephant can easily lift coins or buttons from the floor with its trunk.

From the book Animal World the author Sitnikov Vitaly Pavlovich

Insectivores There are eight families and 374 species. Insectivores live in general where there are no marsupials: on all continents and many islands, except Australia, Tasmania, New Guinea, New Zealand and South America (with the exception of its small areas in the northwestern corner

From the book Mammals the author Sivoglazov Vladislav Ivanovich

Order Insectivores (Insectivora) Small animals with an elongated mobile proboscis, the body is covered with hair, and some have bristles or needles. Many species have developed scent glands. In Dagestan there are common and eared hedgehogs, shrews, common mole.

From the book Anthropology and the Concepts of Biology the author Kurchanov Nikolay Anatolievich

From the author's book

Bats squad This squad includes the bats and fruit bats. The only group of mammals capable of long-term active flight. The forelimbs are turned into wings. They are formed by a thin elastic leathery airfoil stretched between

From the author's book

Order Hare-like These are small and medium-sized mammals. They have two pairs of incisors in upper jaw, located one after the other so that behind the large anterior ones there is a second pair of small and short ones. There is only one pair of incisors in the lower jaw. There are no fangs, and the incisors

From the author's book

Detachment Rodents The detachment unites different types squirrels, beavers, mice, voles, rats and many others. They are distinguished by a number of features. One of them is a peculiar structure of teeth adapted to feeding on solid plant food (branches of trees and shrubs, seeds,

From the author's book

Detachment Predatory The detachment unites quite diverse appearance mammals. However, they share a number of common features. Most feed mainly on vertebrates, a few are omnivores. All carnivores have small incisors, large tapered canines and

From the author's book

Squad Pinnipeds Pinnipeds - marine mammals, which have retained a connection with the land, where they rest, reproduce and molt. Most live in the coastal zone, and only a few species live in the open sea. All of them, like aquatic animals, have a peculiar appearance:

From the author's book

Detachment Cetaceans This detachment unites mammals whose entire life passes in the water. In connection with the aquatic lifestyle, their body acquired a torpedo-like, well-streamlined shape, the front limbs were turned into fins, their hind limbs disappeared. Tail

From the author's book

Order Equid-hoofed animals These are for the most part rather large animals. The number of fingers is different. All equids are characterized by a strong development of the third (middle) finger, which bears the bulk of the body. The rest of the fingers are less developed. On the terminal phalanges -

From the author's book

Artiodactyl squad The squad includes herbivorous animals of medium and large sizes, adapted to fast running. Most have long legs with a paired number of toes (2 or 4), covered with hooves. The axis of the limb runs between the third and fourth

From the author's book

Order Primates This order includes the most diverse in appearance and lifestyle mammals. However, they have a number of common features: a relatively large skull, the eye sockets are almost always directed forward, the thumb is opposed

From the author's book

7.2. Order of primates Man belongs to the order of primates (Primates). To understand the systematic position of a person in it, it is necessary to represent the phylogenetic relationships of various groups of this

Insectivores are one of the orders of mammals. It includes 4 families: shrews, mole, crack-toothed and hedgehog. Many species of this order have become extinct long ago; this is one of the oldest groups of animals that appeared on the planet about 150 million years ago. These animals are widespread, they are not only in Antarctica.

The detachment includes both rather small representatives up to 5 cm in size, and animals up to 50 cm long. The smallest representative is the dwarf white-toothed shrew, it is considered the smallest mammal on the planet. It weighs no more than 1.5 g and grows up to 4.5 cm.

Outwardly, all insectivores look like mice or hedgehogs, have an elongated snout at the end with a mobile proboscis. Their ears and eyes are small. The body is covered with thorns (in hedgehogs, tenrecs) or short fur. Insectivores live from a year to 6 years. The color is usually dark. Many representatives have an unpleasant, repulsive smell due to the presence of special glands, it helps them to escape from enemies. Insectivores are hunted by owls and other birds of prey.

The animals got their name due to the fact that they feed mainly on insects. They also eat small arthropods, worms, small vertebrates (frogs, lizards), bird eggs. Due to this, animals play an important role in eating pests. They eat more food than their own weight per day. A few hours of hunger can kill animals, since they have a very active metabolism.

Most of them prefer to lead a nocturnal lifestyle; in cold climatic zones, many hibernate. Mole representatives of the order live in burrows in the ground, branched, with many passages, thereby mixing the layers of soil. These animals prefer to live in forests near water bodies, desman and some shrews can swim well. Insectivores do not live on trees.

Insectivores have a well-developed sense of smell and touch, and vision is often weak, the brain is also poorly developed. Insectivores are typical loners.

The danger of insectivores for humans is that they can carry infectious diseases. Some members of the order were previously caught for the sake of fur or musk secretions, used to prepare potions.

Option 2

Insectivores are unusual in that they exist in two kingdoms of living nature. There are insectivorous animals and insectivorous plants. Therefore, let's talk about this detachment from both kingdoms.

Insectivores and their features.

These living things are mammals. There are about 450 species in the order. One of the features is the absence of a cecum. At first and for a very long time, insectivores were classified as archaic placentals, and there were reasons for that. They have too small brains, no scrotum, normal skull and teeth. But paleontologists have proven that there are differences from placentals.

The animals are very small, measuring no more than 4.5 centimeters. There was, of course, an exception, but even then, the size did not exceed a small wolf cub. Actually, representatives of the order Insectivorous are the smallest among mammals. It is a pygmy shrew and a tiny shrew.

The mass ranges from 1 to 3 grams. They have existed since the Paleocene. The animals look like a mouse or a hedgehog. Covered with either soft fur or thorns. From the name you can tell what their favorite dish is. Of course, these are insects. But there are other foods as well. The diet includes some arthropods, vertebrates and worms. For humans, insectivores play almost no role. The only thing is that they can be carriers of diseases. For nature, insectivores are orderlies, and they also eat invertebrates and equip the soil. Live from 1 to 6 years. They are nocturnal. They are capable of hibernating.

Can plants eat insects?

Why not? Of course they can. Their other name is carnivorous plants. But why are they doing this? I'll explain now. Despite their creepy reputation, predatory plants are almost indistinguishable from most common plants: they live mainly through photosynthesis. But because they grow in poor soils, they lack many nutrients, including nitrogen and vitamins. To compensate for this deficiency, plants capture and eat animals, mainly insects, but sometimes small mammals, no larger than a rat.

It is worth clarifying right away: predatory plants will not harm a person in any way! Let me give you a fairly well-known example - a sundew. Dew drops can be seen on its small stalks. Do not be fooled, these are sticky, poisonous droplets of mucus with a paralyzing substance. Insects fly to the sundew to drink, and immediately stick tightly. The villi bend towards the victim and digest it for several days.

Life and work of Kosta Khetagurov

The future poet was born in the fall of 1859 in the small Ossetian settlement of Nar. The boy's family was of a noble surname, and his father, in addition, was a Russian officer. But despite this, as Costa later recalled

Insectivores are a detachment of primitive placental mammals of the chordate type. These are the most ancient animals, the development of the embryos of which occurs through the formation of the placenta. They appeared on Earth during evolution at the beginning of the Cretaceous period. Paleontologists consider the ancestors of insectivorous progenitors of all placental mammals.

The order insectivorous unites seven families: mole, hedgehog, slot-toothed, hopping, golden-mole, tenrec, and shrew. The orders, in turn, are divided into more than 60 genera, including more than 300 species. Representatives of insectivores - hedgehog, shrew, mole, desman.

Insectivores are widespread throughout the world, except for Antarctica, Greenland, Australia and most of South America. These animals settled in different habitats: ground (shrews, hedgehogs), water (desman, otter shrews), soil (moles, golden moles). Insectivores are predominantly nocturnal. They are omnivorous, but give preference to animal food, feeding on invertebrates (including insects - hence the name of the order) and small vertebrates. Many of the insectivores dig holes in which they hide from enemies. Some species hide in the forest floor. Insectivores are active throughout the year, rare species from the hedgehog family are able to hibernate for the winter.

Insectivorous mammals are usually small to medium in size. The cover of the body of shrews and moles is short dense wool, tenrecs - bristles, hedgehogs - needles. The color of the coat is varied - from gray to black, sometimes spotted. Insectivores have an elongated head, often with a mobile proboscis with long sensitive hairs. The eyes and ears of these animals are small and almost invisible. They have a very well developed sense of smell and touch. The teeth of all animals of this group are poorly differentiated. The limbs of most insectivorous species are plantigrade, each having five toes with claws. The tail can be almost invisible, like a hedgehog, or equal in length to the size of the body, like a desman. In the skin of animals there are special skin glands, in some species they secrete a secret with a strong odor.

The structure of the brain has characteristics... The large hemispheres have a primitive structure without convolutions. They are small in size and do not cover the cerebellum, and the olfactory part of the brain is well developed.

Insectivores are polygamous animals. They breed 2-3 times a year, and there can be from one to twenty cubs in the litter.

The significance of insectivores is that they are members of various natural biocenoses. For humans, some species of insectivores are objects of fur trade (moles, desman). Insectivores eat arthropods - pests of agriculture and forestry. But they themselves can be dangerous to people, since some of them are intermediate hosts of ticks - carriers of serious diseases. Rare species of insectivores, such as desman, crack-tooth, are listed in the Red Book and are under protection.

Lesson type - combined

Methods: partial search, problematic presentation, reproductive, explanatory and illustrative.

Target: mastering the skills to apply biological knowledge in practice, use information about modern advances in biology; work with biological devices, instruments, reference books; to conduct observations of biological objects;

Tasks:

Educational: the formation of a cognitive culture, mastered in the process of educational activity, and aesthetic culture as an ability for an emotional-value attitude towards objects of living nature.

Developing: development of cognitive motives aimed at obtaining new knowledge about living nature; cognitive qualities of a person associated with the assimilation of the foundations of scientific knowledge, mastering the methods of studying nature, the formation of intellectual skills;

Educational: orientation in the system of moral norms and values: recognition of the high value of life in all its manifestations, the health of one's own and other people; environmental awareness; education of love for nature;

Personal: understanding the responsibility for the quality of acquired knowledge; understanding the value of an adequate assessment of one's own achievements and capabilities;

Cognitive: ability to analyze and evaluate the impact of factors environment, risk factors on health, the consequences of human activity in ecosystems, the impact of one's own actions on living organisms and ecosystems; focus on continuous development and self-development; the ability to work with various sources of information, transform it from one form to another, compare and analyze information, draw conclusions, prepare messages and presentations.

Regulatory: the ability to organize independently the fulfillment of tasks, to assess the correctness of the work, reflection on their activities.

Communicative: the formation of communicative competence in communication and cooperation with peers, understanding the characteristics of gender socialization in adolescence, socially useful, educational and research, creative and other types of activity.

Technology : Health preservation, problem-based, developmental learning, group activities

Activities (content elements, control)

Formation of students' working abilities and abilities for structuring and systematizing the studied subject content: collective work - studying the text and illustrative material compiling a table "Systematic multicellular groups" with the advice of student-experts with subsequent self-examination; pair or group execution laboratory work with the advice of a teacher, followed by a mutual check; independent work according to the material studied.

Planned results

Subject

understand the meaning of biological terms;

describe the structural features and basic life processes of animals of different systematic groups; to compare the structural features of protozoa and multicellular animals;

to recognize organs and systems of organs of animals of different systematic groups; compare and explain the reasons for the similarities and differences;

to establish the relationship between the features of the structure of organs and the functions that they perform;

give examples of animals of different systematic groups;

to distinguish in figures, tables and natural objects the main systematic groups of protozoa and multicellular animals;

to characterize the directions of evolution of the animal world; provide evidence of the evolution of the animal world;

Metasubject UUD

Cognitive:

work with different sources information, analyze and evaluate information, transform it from one form to another;

draw up abstracts, different kinds plans (simple, complex, etc.), structure educational material, give definitions of concepts;

conduct observations, set up elementary experiments and explain the results obtained;

compare and classify, independently choosing the criteria for the specified logical operations;

build logical reasoning, including the establishment of cause-and-effect relationships;

create schematic models highlighting the essential characteristics of objects;

determine possible sources of the necessary information, search for information, analyze and evaluate its reliability;

Regulatory:

organize and plan your educational activities - to determine the purpose of the work, the sequence of actions, set tasks, predict the results of the work;

independently put forward options for solving the tasks set, foresee the final results of the work, choose the means of achieving the goal;

work according to the plan, check your actions against the goal and, if necessary, correct mistakes yourself;

possess the basics of self-control and self-assessment for making decisions and making informed choices in educational and cognitive and educational and practical activities;

Communicative:

listen and engage in dialogue, participate in collective discussion of problems;

integrate and build productive interaction with peers and adults;

adequately use speech means for discussion and argumentation of their position, compare different points of view, argue their point of view, defend their position.

Personal UUD

Formation and development of cognitive interest in the study of biology and the history of the development of knowledge about nature

Receptions: analysis, synthesis, inference, translation of information from one type to another, generalization.

Basic concepts

Diversity of mammals, division into orders; general characteristics of detachments, the relationship between lifestyle and external structure. The importance of mammals in nature and human life, the protection of mammals.

During the classes

Knowledge update ( concentration of attention when studying new material)

Choose the answer that is correct in your opinion.

1. How many species of marsupials are there?

2. What is the marsupial bag used for?

For storing water

For bearing cubs

For storing food

3. What do kangaroos eat?

Insects

Plant food

4. How do kangaroos move?

Somersaults

Jumping

5. What representative of marsupials feeds on fish?

River possum

Marsupial wolf

6. What trees do koalas live on?

On the pines

On eucalyptus

7. What is the name of the koala?

Marsupial mole

Marsupial bear

Marsupial beast

8. How do representatives of marsupials live in the soil?

Marsupial cat

Marsupial mole

With possum

9. What size can an adult kangaroo reach?

2 meters

10. Where do marsupials not live?

In Australia

In North America

In Asia

Learning new material(teacher's story with conversation elements)

Squad Insectivores.

Brief description of the detachment... These include animals of medium and small size, with an elongated muzzle ending in a proboscis. Insectivores include hedgehogs, moles, desman, shrews, and shrews. The largest representative of the order is the common desman, up to 22 cm long, with an equally long scaly tail, compressed from the sides. All insectivores, except for hedgehogs, have a short coat. The smallest representative is a crumb shrew, up to 4 cm long. The animals of this order are considered ancient mammals.

The vital organs of the representatives of this order have retained the primitive features that were inherent in ancient animals. So, the large hemispheres of the brain of insectivores almost do not contain convolutions, the skull has an elongated shape, the teeth are sharp, lumpy, it is difficult to divide them into groups. Most of the animals that belong to this group are small in size, the skin is represented by short soft hairs or short spines, paws have five fingers. Many of these creatures are mostly nocturnal, but some are active during the day. From the name of the detachment it is clear that the basis of their diet is various insects.

Garden warrior. The secret life of the European hedgehog

The mole is also a prime example of insectivores.... These mammals share many of the characteristics of this class, but there are also distinctive features. The skin of moles, in contrast to the hedgehogs discussed above, is presented in the form of short dark wool. The front paws of these animals have a rather specific appearance for insectivores - they are enlarged, long claws are located on them, since they are intended for convenient digging of the ground. Moles live in the ground, where they make holes with numerous nests and tunnels. Here it is convenient for them to find food in the form of earthworms, larvae of various insects, etc. distinctive feature the mole is underdeveloped eyes - since he lives underground, he practically does not need them; the main sense organ is the nose. -

how moles behave on the ground

Mole- Mole

Shrews. Speaking about which animals are insectivores, we must also mention them. Each of us at least once had to hear about this funny animal. It is as widespread on the Eurasian continent as the "brothers" described above. These animals are found almost everywhere, except Australia, South America and Antarctica. These are small creatures covered with sparse fur, active at any time of the day. They eat, of course, insects and ... other small animals that are found in the ground, which is clear from their name. Sometimes they also eat seeds. The family of shrews includes shrews and shrews. They bring great benefits, like hedgehogs, destroying many harmful insects.

Shrews

Shrew!

Little-known representatives of this squad

And now let's talk about those representatives of the detachment we are considering, whom not everyone knows, so to speak, in the face (well, or in the face). So which animals are insectivores? For example, the tenrec family. These creatures are very similar to hedgehogs, before they were even ranked as one family. Tenrecs live in Madagascar and the Comoros. This is a very ancient family of insectivores, representatives of which have been known since the Cretaceous. They, like hedgehogs, have spines, usually of a dark color. Some species have yellow spots on them. An interesting feature these animals are characterized by extremely low metabolism and absolutely low body temperature, which is usually not typical of mammals.

Tenreki. Bristlyhedgehogs

Another interesting and little-known ordinary people view - crack-toothed... These are insectivorous animals that differ in quite large size... Their habitat is Cuba and Haiti. They look like large shrews or rats, but have longer legs and, unlike rats, a longer proboscis-like snout. It is interesting that the crack-tooth belongs to a few poisonous mammals, the poison is secreted by a gland, the duct of which is located on the lower jaw. Listed in the Red Book. The jumper is also an example of insectivores. Most of all, he resembles a jerboa, and lives in Africa. The basis of his diet is termites, other insects, seeds, small fruits.

In this lesson, you will learn about the general characteristics of the group of animals to which we belong - mammals, that is, animals that feed their young with milk. The lesson will focus not only on the most primitive mammals, which, like birds and reptiles, lay eggs, but also on real animals (marsupials) and higher animals (placentals). You will learn how mammals differ from reptiles and birds, what are the features of internal fertilization and internal development of embryos. From the higher animals, you will get acquainted in more detail with insectivores and bats. You will find out how wrong you were in the good nature of the hedgehogs and the viciousness of the vampire bats. In addition, you will get acquainted with the origin, amazing abilities and records of representatives of our class.

Homework

1. Give general characteristics mammals. What are the subclasses of this class?

2. What do the first animals have in common with animals, birds and reptiles?

3. What animals are cloacal?

4. What are the features of the external and internal structure typical for real animals?

5. How do higher and lower beasts differ from each other?

6. What structural and physiological features are characteristic of insectivores and bats? What representatives of these units live in your region?

7. Discuss with friends and family the importance of mammals in nature and economy.