The most amazing paws in the animal kingdom. Geographical laws and some environmental factors

Ecology

Hands for a person are one of the most important parts of the body. We do almost everything with our hands, even communicate. However, man is not the only creature on the planet with dexterous hands and fingers. The limbs of animals, which are commonly called paws, can surprise a lot. We invite you to learn about the most unusual paws in the animal world.

Amazing animals

Threatening Aye-Aye

Aye-aye- an amazing creature that lives in Madagascar, which can “show middle finger"like no one else in the world. Aye-aye or little arm- a small primate that can be called the strangest of all primates. It has ugly, bony paws with long fingers and claws, reminiscent of heroes from fairy tales about vampires and werewolves.

Moreover, the middle finger of the hand is slightly larger than the others and protrudes noticeably. With his help the beast knocks on trees looking for voids in the bark, where tasty insects on which it feeds can hide. If an aye-aye finds a treat, it bites through the wood and, with the help of its sinister long finger catches prey.

Little hands, despite their threatening appearance, completely harmless for everyone except insects, however, the inhabitants of Madagascar are very unfriendly to these animals, considering meeting them a bad sign. If an aye-aye is seen near a village, he will be killed immediately, as it is believed that otherwise misfortune will befall the village.

Helen the Flying Frog

In 2009, while traveling through the forest near the Vietnamese city of Ho Chi Minh City, biologists came across amazing frog. This frog is long about 9 centimeters, as it turned out, belonged to a new species of flying frogs unknown to science, which are known for their ability to jump from one tree to another and float in the air using special webbed paws.

Biologist Judy Rowley, who discovered this frog in Vietnam, gave it its name flying frog helen in honor of his mother Helen Rowley.

The most amazing animals

Many-toed mole

Moles- very cute animals, with the possible exception of Mole Starsnout, which lives in the USA and Canada. Moles have amazing limbs, which they simply need in order to travel underground.

The large, flat front paws work like shovels, and the long claws on the toes allow dig underground holes and tunnels, in which moles find shelter and food.

In 2011, researchers University of Zurich suggested why mole paws dig the ground so well: moles have one extra finger– sickle-shaped spare thumb.

This thumb has no motor joint, mole leans on him while digging, which gives its shovel claws extra strength. Studies have shown that the bone of this finger develops from the bones of the wrist at the embryonic stage somewhat later than the bones of the other fingers. Moles really have not 5, but 6 fingers on your paws!

Sticky gecko

Geckos boast amazing paws that allow them to cling almost for any surface. The lines on the soles of their paws are covered with hairs called bristles, which are also covered with bristles.

The latter structures are so small that they allow geckos to stick to the surface on which they move. They allow you to strengthen van der Waals force, a weak electrical force that holds many things together, including most organic matter.

The author, in love with his science - zoogeography, claims and proves that it is as interesting as everything connected with the life of animals in the wild. He talks surprisingly clearly about the biological properties of animals that help them exist in a certain environment, about the connections of fauna with plant formations, about the distribution of animals around the globe and about the factors limiting their settlement, about the history of the development of fauna on various continents.

Book:

Gloger's Law. Already in the last century, zoologists noted that terrestrial animals living in areas with humid climate, turn out to be darker colored than animals of the same or similar species inhabiting arid areas. This phenomenon was scientifically analyzed and formulated as a zoogeographical rule by Konstantin Albert Gloger, who published the book “Changes in Birds Under the Influence of Climate” in 1833 in Wroclaw.

The noted pattern turned out to be common for both vertebrates and invertebrates. Laboratory experiments with field crickets (Gryllus campestris) showed that when crickets were kept in a room where the relative air humidity was maintained at 60–80%, they acquired a rich dark color.

The unwitting participants in such an experiment were birds - medium-sized grosbeaks (Munia flaviprymna), living in the desert interior of Australia. Several birds of this light-colored desert species were introduced to England and kept in captivity. After three years of living in the humid English climate, dark spots appeared on the birds' plumage, enhancing the similarity of this desert species with a dark-colored related species, the Grosbeak Munia castaneithorax, living in the humid coastal forests of Australia.

Later this pattern was confirmed by many examples. The simplest of them: variability of gastropods Arianta arbustorum And Succinea pfeifferi, living in the Middle and Eastern Europe, grass frog (Rana temporaria) and viviparous lizard (Lacerta vivipara). Interestingly, American moles Scapanus in the states of Washington and Oregon they have black fur, in Northern California, where the climate is drier, they are brownish, and in Southern California, where it is even drier, their fur is light, silver. This biogeographical pattern is called Gloger's law.

The color and intensity of the color of the outer integument of animals depend on the amount of pigment - melanin, and its formation is influenced not only by air humidity, but also by environmental temperature. Low temperature causes the color to lighten; high temperature, on the contrary, causes darkening. The combined effect on the animal’s body of both of these factors (environmental humidity and its temperature) gives exactly the resulting effect that we usually observe. In some cases, there are exceptions to Gloger's law caused by different combinations of humidity and air temperature. Thus, the fur of wolves from Belarus has a lighter, ashen color than that of wolves from the Pyrenees - rather dark, with a brownish tint.

Temperature. Ambient temperature is a powerful factor that influences and often determines the distribution of living organisms on earth. Temperature fluctuations on land, including soil surface temperature, have a very wide range - from +80° to -70 °C. And in the oceans it is almost 5 times less: from +30° to -2 C.

Temperature changes on land can sometimes be very rapid. Some natural areas are characterized by changes in ambient temperature by several tens of degrees during the day. The aquatic environment does not know such temperature contrasts.

In many cases, terrestrial animals have developed a deep differentiation of organisms according to their requirements for the thermal conditions of their living environment.

Animals are stenothermic and eurythermic. Each species of animal has its own range of temperatures that are most favorable for life, which is called the temperature optimum of a given species. This temperature range, that is, the limits of the temperature optimum, can be relatively wide in some species, while in others it covers only a few degrees. If the temperature optimum for a species is narrow and normal functioning the body is violated when it goes beyond this temperature limit, and also if the animal does not tolerate fluctuations in environmental temperature, then this species is called stenothermic.

On the contrary, animals that exist safely in a wide range of environmental temperatures, that is, having a wide variety of temperature optimums, are called eurythermal species. They usually do not die, even if they have to exist for some time in conditions beyond the temperature optimum.

There are relatively more stenothermic organisms in the ocean than on land. Among stenothermic species, cold-loving or oligothermic ones stand out, such as, for example, polar bear and musk ox; thermophilic, or polythermic (giraffes, apes, termites, etc.), and animals that require moderate but constant temperature environment. In general there are not many of them.

Eurythermal species in to the greatest extent characteristic of temperate latitudes, where seasonal contrasts in living conditions are well expressed. Eurythermal organisms are characterized by a wide distribution. For example, the species range (geographical distribution area) of the common toad (Bufo bufo) extends from northern Africa in the south to Sweden in the north, where this amphibian is found even north of Stockholm. And on the North American continent there is another type of toad (Bufo terrestris) found from Florida to Hudson Bay. The wolf, weasel, ermine and many other mammals and birds living both in the tundra and in the steppes and hot deserts have a no less extensive range.

If an isolated area with a special climatic regime appears in any natural zone, reminiscent of the conditions of another zone (for example, with a warmer microclimate), then such a place can be inhabited by animals not native to this zone. This is how “outposts” of the southern fauna arise, pushed to the north and reminiscent of “islands” from southern species, whose temperature optimum does not correspond to the natural zone. Such an “island” of heat-loving fauna was discovered in Germany, in the vicinity of Freiburg, in the southwestern corner of the Black Forest. In Poland, there is a similar “island” in the vicinity of Krzyzanowice, in the Nida Valley.

Biological effects of high and low temperatures various. At a temperature of about 55 °C, proteins in the protoplasm of cells coagulate and most animals die. Low temperatures do not cause protein coagulation, so many animals have adapted to withstand low temperatures by hibernating or entering a deep anabiotic state, after which, when favorable conditions occur, they are able to return to active life.

The response to temperature differs significantly between so-called cold-blooded and warm-blooded animals.

Cold-blooded animals. The vast majority of animal species are cold-blooded, or, as scientists say, poikilothermic: all invertebrates and lower vertebrates, up to and including reptiles. The body temperature of cold-blooded animals is close to or equal to the ambient temperature and changes following changes in the latter. A cold snap occurs - and the body of a cold-blooded animal becomes colder. With warming, the body temperature rises. Marked in deserts maximum temperatures bodies close to 50 °C in young mantises (genus Mantis) and grasshoppers moving on sand, the temperature of which reached 50.8 °C.

In insects that winter in temperate climates (for example, in Poland or generally in Central and Eastern Europe), the body temperature (or pupae and eggs) is close to 0°.

Most cold-blooded animals prefer warm climates, and most of them live in the tropics. If we conditionally divide the earth into a cold zone, temperate and hot, then the number of arthropod species in them would correspond accordingly, as 1: 4: 18.

In cold-loving and heat-loving species of butterflies from the family Syntomidae these belts have even more expressive ratios - 1:3:63. This pattern is also characteristic of scorpions, spiders, centipedes and even reptiles. Thus, in Poland, on an area of ​​312 thousand square kilometers, eight species of reptiles live, and on the island of Java, with an area of ​​only about 132 thousand square kilometers, 122 species are known.

This pattern is easy to understand. In a warm climate, cold-blooded animals lead an active life throughout the year, while as they move into colder areas, the time of their active life is increasingly limited by a shortening of the season of favorable temperatures, and winter, early spring and late autumn become a period of long rest (hibernation, diapause, suspended animation).

The intensity of metabolism in an animal's body is complexly dependent on the ambient temperature. It is believed that the rate of biochemical processes increases 2–3 times with an increase in temperature by 10 °C. This refers, of course, to changes in temperature within the range of normal values ​​that are well tolerated by a given animal species. The dependence of the rate of metabolism (metabolism) on ambient temperature can be studied experimentally.

It has been established that the mealworm larva (mealworms) at an environmental temperature of 15 °C consumes 104 cubic centimeters of oxygen per hour per kilogram of body weight, at 25 °C - 300 cubic centimeters, and at 32.5 °C - 520 cubic centimeters.

Accelerating the metabolic process reduces the time the body goes through stages individual development, shortens the duration of the ontogenesis stage. Before metamorphosis begins, the larvae will require different amounts of time depending on the temperature at which they were previously kept.

The speed at which the mealworm beetle passes through the pupal stage (from the moment of pupation until the adult beetle emerges from the pupae) depending on the ambient temperature is presented in the table:

From this experiment it is clear that an increase in environmental temperature by approximately 20 °C caused a reduction in the duration of the pupal stage by more than 8 times, that is, development was significantly accelerated.

Under natural conditions in temperate climatic zone the rate of individual development of many invertebrates is low, winter causes a long period of depression in vital activity, and as a result, the number of generations appearing in one year is small - often one or two.

In hot climates, the rate of individual development of invertebrates is often higher, periods of depression are shorter or in some natural areas are absent altogether, and accordingly, several, and in some species even more than ten, generations can be produced during the year.

To illustrate this pattern and to clearly imagine the potential reproduction capabilities of invertebrate animals in a hot climate, we will calculate the size of the offspring of some conventionally taken, even fictitious, insect species, for example, represented only by females that reproduce parthenogenetically, that is, without the participation of males. And such species exist in nature!

Developing in the most favorable conditions, in the optimum, which is located for cold-blooded animals between the tropics, they reach their largest sizes here. Tropical centipedes reach a length of 15 and even 20 centimeters and are as thick as a finger, while the largest centipede from temperate latitudes in Europe is no more than 4 centimeters in length. Scolopendras from equatorial countries are gigantic size, up to 27 centimeters long, and in Yugoslavia there are maximum length- 8-10 centimeters, in Poland they are no longer found at all, there you can only find kilts (Lithobius).

And this is a direct influence of climatic conditions. The cold-blooded animals of the tropical regions of America, Africa and Asia are similar in size and appearance, although their species are usually different on different continents.

Here are some more examples of the same pattern. There are several species of scorpions found in Europe, but individuals of any of these species almost never exceed three centimeters in length. IN low latitudes lives more types scorpions, while the undisputed primacy among them in size belongs to the imperial scorpion (Pandinus imperator), covered with black armor and reaching 18 centimeters in length from the front edge of the shell to the poisonous spine at the end of the abdomen. Such “emperors” live in West Africa.

Tropical butterflies and beetles provide remarkable examples of gigantism. Suffice it to recall Brazilian butterflies, many of which have a wingspan of more than 20 centimeters, the Hercules beetle (Dynastes hercules) 15 centimeters long or huge bugs from the family Belostoma, slightly similar in appearance to a water scorpion (Nepa), living in our European reservoirs, but 10 centimeters longer than it. No less vivid impression than the Hercules beetle, the West African Goliath beetle also produces (Goliathus giganteus), although it reaches a length of only 10 centimeters. But it has terrible pincers the size of a third of the body length, formed from two horns: one on the head, and the other on the first segment of the cephalothorax.

In the tropics there are large gastropods from the family Achatina, having shells up to 17 centimeters long and weighing more than 500 grams.

Examples among cold-blooded animals are no less striking and abundant. Let's remember crocodiles, which inhabit mainly tropical waters, huge snakes - pythons, boa constrictors and anacondas. In the tropics there are often very large Poisonous snakes: for example, spectacled snakes - cobras (Naja) in Asia or terribly dangerous African vipers (Bitis arietans And Bitis gabonica).

American iguanas (family Iguanidae), resembling our lizards, and monitor lizards (family Varanidae), inhabiting Africa and hot regions of Asia. The body length of many species of monitor lizards and iguanas often exceeds one and a half meters. The largest living monitor lizard is the Komodo dragon. (Varanus komodoensis), inhabiting two small islands in Indonesia between the islands of Sumbawa and Flores; These are real monsters, three meters long, with a heavy body and powerful limbs.

Warm-blooded animals. Only birds and mammals have warm blood. Complex physiological mechanisms allow them to maintain a constant and fairly high body temperature. Different species of birds and mammals have different body temperatures, but always generally within the range of 30 °C to 44 °C. In a healthy animal, temperature fluctuations usually do not exceed half a degree. The exceptions are the Australian platypus and echidnas, whose normal body temperature is lower than that of all other mammals and is only 3 °C. To many of the primitive features characteristic of these ancient mammals is added a certain dependence of their body temperature on the ambient temperature, which is expressed in a wider range of temperature fluctuations, reaching 4 °C both above and below the average norm, and which makes them similar to reptiles .

To maintain a high and constant body temperature, the animal’s body spends a large number of energy, which, in addition, is spent on thermal radiation. Consequently, warm-blooded animals must have an intense metabolism and conduct active image life, that is, consume a lot of food and quickly absorb it, and these processes, in turn, are facilitated by high body temperature.

Warm-bloodedness is an invaluable property of animals, acquired in the process of organic evolution, which opened up for them to explore vast living spaces of temperate and polar latitudes and highlands, inaccessible to most species of cold-blooded animals. The polar margins of continents, Arctic islands and even floating ice floes serve as an arena of active life for birds and mammals.

Temperate zones in both hemispheres of the Earth have snowy and cold winters, and during this harsh season for animals, warm-blooded animals literally reign here. They lead an active life, and some species, such as our crossbills, even reproduce and are able to feed their chicks, while cold-blooded animals experience a period of low temperatures, being in an inactive or even anabiotic state. That is why, in the fauna of areas with cold climates, birds and mammals make up a relatively higher percentage in terms of the number of species than in the tropics.

However, winter also turns out to be a difficult time of year for warm-blooded animals. Think about it, the difference between the body temperature of an animal and the environment, even in Central and Eastern Europe, for example in Poland, can sometimes reach 75 °C. This causes enormous heat loss in living organisms and turns into a “to be or not to be” problem.

In the system of thermoregulatory mechanisms of the body of warm-blooded animals, an important place belongs to the outer integument of the body, which has a heat-insulating function. It's easy to see this with your own eyes. Birds living in cold regions have a much more significant layer of warm, soft down under their covert feathers than those living in the south. In addition, in the north of our hemisphere you will not find birds with bare heads and necks, such as vultures, vultures and cassowaries. The coat of mammals also consists of two layers: guard hairs and a thick down under them. The density and thermal insulation properties of the down fluff are directly related to the characteristics of the environment and life. And here is an example that can be seen at the zoo. Take a closer look at the Himalayan (Helarctos tibetanus) and Malay (Helarctos malayanus) to bears. These are related species. They are similar in appearance too. But himalayan bear looks like a “stack of wool”, since it is a resident of the cold highlands, and the Malay has smooth, low, velvety hair, like many animals of the tropics.

The difference in the characteristics of the coat can be clearly expressed within the same species. The Ussuri tiger has to wander in deep snow, and its entire body is covered with long and fluffy hair, which is especially long on the nape and chest. And the Bengal tiger is overgrown with short, smooth hair, almost without any down.

It is known that even the cost of furs (for example, foxes and skunks) is affected by the region from which they are obtained: the skin is more expensive the further north it is obtained.

Only in the tropical zone, in warm climates, are there animals covered with sparse hair or even hairless: hippos, rhinoceroses, elephants, and some types of buffalo.

Bergman's law. The coat of mammals, especially thick and lush in high latitudes, and the plumage and warm down of birds protect the animal’s body from hypothermia. However, the problem of thermoregulation is not completely solved only with the help of various adaptations of integumentary tissues.

In 1847, a study by the German zoologist Karl Bergman “On the connection between heat savings in animals and their size” was published in Göttingen. Carl Bergman drew attention to the fact that animals that live in cold climates are usually larger in size than individuals of the same species that live in warmer climates. This is not an accident, but the result of a vital adaptation of animals, based on a simple mathematical pattern. After all, heat loss occurs through the surface of the body, and the larger this surface is relative to the volume of the body, the greater the heat loss. And organisms that are larger in volume have a relatively smaller surface area per unit of weight (mass).

If, for example, we take a cube with a side of 1 centimeter, made of a substance with a specific gravity of 1 g cubic. cm, then the total surface area of ​​all six faces will be 6 square centimeters, and the volume will be 1 cubic centimeter, that is, a mass of 1 gram. When calculating the surface of a cube per unit mass, we get 6 square centimeters/gram.

If you then take a cube with a side of 2 centimeters, that is, twice as large, then the surface of the six faces will be 24 square centimeters, and the volume will be 8 cubic centimeters and, accordingly, the mass will be 8 grams. When calculating the surface area per unit volume or mass, the result is 3 square centimeters/gram. So, a cube that is twice as large in volume has a relative surface area that is half as large.

In the language of a biologist, this pattern means that an animal with twice the size gives off half as much heat per unit of body mass (of course, all other things being equal). Consequently, a larger animal, giving off relatively less heat per unit weight, can consume relatively less feed than a smaller animal. This means that when the food supply is limited, a larger animal survives more easily than a small one.

This pattern constitutes the essence of Bergmann's zoogeographical law. Examples confirming this are numerous in all parts of the world. For example, wild boars from Southern Spain have skulls with an average length of 32 centimeters, in Poland - about 41 centimeters, in Belarus - 46, and in Siberia there are huge wild boars with a skull length of 56 centimeters. A change in the size of animals in accordance with Bergmann's law can be observed in white hares, roe deer, foxes, wolves, bears and other species of mammals. In Europe, these animals become smaller towards the southwest and, on the contrary, increase towards the north and east in those areas where winters are harsher.

Geographic size variations in birds also follow the principles of Bergmann's law. For example, horned larks (Eremophylla alpestris), living in North America clearly demonstrate this pattern, as can be judged by changes in wing length: in larks from the shores of Hudson Bay, the wing length is 111 centimeters, in birds from Nevada - 102 centimeters, and on Santa Barbara Island, off the coast of California , - only 97 centimeters. Subspecies of animals from colder regions tend to be larger in size than subspecies from lower latitudes with warmer climates. For example, the European blue kingfisher (Alcedo atthis ispida), beautiful widespread small rivers, but everywhere the bird is not numerous, it turns out to be the largest in comparison with other subspecies of this kingfisher: Alcedo atthis pallida- the pale blue kingfisher inhabiting Syria and Palestine, and the Bengal Alcedo atthis bengalensis- the smallest of the blue kingfishers, living in India and Indonesia. Likewise, the European subspecies of oriole (Oriolus oriolus oriolus) noticeably larger than the eastern oriole (Oriolus oriolus kundoo) from Afghanistan and central regions India.

In the southern hemisphere of the Earth, on the contrary, the increase in animal size occurs towards South Pole, that is, also in accordance with the principle of Bergmann's law: the size of animals in colder climates increases. And here is an example from southern hemisphere. On the Galapagos Islands, in the tropical zone, lives a small penguin - Spheniscus mendiculus 49 centimeters tall, to the south, from the islands of Tristan da Cunha to Tierra del Fuego, that is, in temperate conditions oceanic climate, lives a larger penguin - Eudyptes cristatus, whose body length reaches 65 centimeters. Even further south, up to 60° south latitude, the penguin is widespread Pygoscelis raria, reaching 75–80 centimeters. On the coast of the continent of Antarctica lives a huge emperor penguin - Aptenodytes forsteri height 120 centimeters and above.

If two relatively closely located territories have similar faunas, but differ in average temperatures, that is, one of them is colder, then it is on this territory that the average sizes of both mammals and birds will be larger. And here are examples of such fauna pairs. On the south coast of Australia the average annual temperature is 16 °C, and on the coast of Tasmania it is 11 °C. And this is already enough for all Tasmanian platypuses, echidnas and kangaroos to be larger than Australian ones. A similar picture can be observed in New Zealand. The North Island of New Zealand is warmer than the South Island. Average annual temperature in the North it is 16.6 °C, and in the South it is 10.4 °C. And accordingly, parrots and kiwis turn out to be larger by South Island, and not in the North.

There are exceptions to the rule discovered by Bergman, which can be understood and explained in each specific case. On the one hand, these are migratory birds, which, even if they nest in the north, in the northern hemisphere, still do not experience the influence of Arctic cold, since they quickly complete the breeding season and move to warmer climes. When migrating, they are always in more or less favorable conditions.

Another example is provided by small mammals: voles, mice, shrews, which spend most of their time in the specific microclimate of their burrows, more or less stable and often milder than the climate of the surrounding area. Active in winter under a layer of snow, they are in conditions significantly different from those that prevail above the snow-covered plain, since snow has a great thermal insulating effect. And the temperature distribution in central Alaska was studied different heights and under the snow. The snow cover was relatively thin - 60 centimeters. stood very coldy. The thermometer showed -50 °C, and under the layer of snow on the surface of the soil the frost did not even reach -7 °C. And under these conditions, gray voles (genus Mucrotus) They led an active life and moved freely in their snowy passages, although their fur coat was thin and their paws were not covered with hair at all. At the same time, the caribou had great difficulty surviving the severe cold. Thus, we can say that these two species of mammals, being in the same geographical point, existed in completely different climatic conditions, as if their habitats were separated by tens or hundreds of miles.

Laboratory experiments also confirm the pattern noted by K. Bergman. White mice kept since early age at low temperature, equal to only +6 °C, grew significantly larger than those that were in average conditions during the same period of time normal temperature environment equal to +26 °C. The same experiment was carried out on chickens with no less success. And since then, the method of “cold raising” of chickens has become widely used in poultry farming to increase the industrial yield of meat products.

Allen's Law. For animals that live in cold regions of the Earth, it is advisable to reduce the surface area of ​​the body relative to its mass. This is achieved in two ways: by increasing the overall size of the body and reducing the size of all prominent organs and parts of the body: ears, muzzle, legs, tail. Polar animals have shorter ears, tails, and muzzles than animals inhabiting areas with temperate and especially hot climates. Even the paws and necks are shorter and thinner in polar animals. This phenomenon is called Allen's law.

The most common example of Allen's law is the polar fox comparison (Alopex lagopus) with short ears and muzzle, short, with a small tail and our red fox (Vulpes vulpes), taller and more graceful. Exactly the same for the white hare (Lepus timidus), living in the north, the ears are shorter than those of the brown hare (Lepus europaeus), common to the south. It is worth comparing a reindeer with a red deer to make sure that the former has shorter ears and shorter legs.

Allen's rule is confirmed in the laboratory, where mice kept in cold conditions had shorter ears and feet, and those raised at elevated temperatures had longer than normal ears. The length of the legs of chickens in the experiment also turned out to be dependent on the environmental temperature.

From Allen's law it logically follows that an animal with a particularly large relative body surface area should live only in low latitudes, in the tropics and subtropics. Long-eared fennec foxes live in hot climates. The savannahs of Africa are home to the long-legged giraffe, no less famous for its exorbitantly long neck, and the small graceful gerenuk antelope. (Lithocranium walleri).

The same pattern is clearly visible in the example bats. Flying dogs, or flying foxes belonging to the suborder of large frugivorous bats (Megachiroptera), have a huge wing surface, and they are common only in the tropical zone. A suborder of smaller fruit-eating bats, Microchiroptera, consists of 16 families. Representatives of 13 families live in tropical and subtropical zones, and only the bats of the three remaining families were able to settle all the way to temperate latitudes. IN Central Europe Horseshoe bats are the most common (Rhinolophidae) and leather jackets (Vespertilionidae).

Minimum rule. In the fifties of the last century, the German chemist Justus Liebig became interested in plant life, fertilizers and laid the foundations of the science of agrochemistry. At the same time, he formulated a rule according to which the factor limiting the development of a plant is an element that is at a minimum, that is, one that the plant may lack. For example, if a plant is given what is necessary for its life and even large quantity nitrogen, phosphorus, iron and all other necessary elements, but at the same time one element, potassium, is given less than the required norm, then the plant will grow stunted and stunted. Its growth will be limited by a lack of potassium.

Liebig's minimum rule applies equally to plants and animals. If an animal or a person is given food without vitamin C, they will develop scurvy, even if the food is plentiful, delicious and tasty. The condition of the body in this case is determined by a factor that is in a minimum or completely absent, like vitamin C mentioned in our example, and not by factors that are in excess. If a rat is kept on a protein-free diet, it will grow poorly, remain small and frail, and will soon die, despite the fact that it will be given plenty of carbohydrates, fats, vitamins, and microelements.

Not only plant and animal organisms, but also animal groups, populations, species and biocenoses are subject to the minimum rule. Any environmental factor can limit the development of a population or any biocenotic connections if it is present at a minimum.

Knowledge of this rule allows you to effectively apply it in hunting and forestry.

The number of gray partridges is limited primarily by the lack of food in winter period and exposure to predators. Therefore, to increase the number of partridges in hunting It is necessary not so much to limit their shooting and import dozens of individuals caught in other places, but to organize feeding of birds in winter and create plantings that include dense clumps of bushes in which partridges could hide from predators.

As for small insectivorous birds, they are mainly provided with food in natural conditions. The factor limiting their numbers is often the lack of places suitable for making a nest. That is why, with the help of artificial nesting sites (loop houses and birdhouses) and planting artificial plantings, the number of useful songbirds can quickly increase.

In this post there will be scary, nasty, cute, kind, beautiful, incomprehensible animals.
Plus a short comment about each. They all really exist
Watch and be surprised

SNAP TOOTH- a mammal from the order of insectivores, divided into two main species: the Cuban slittooth and the Haitian. The animal is relatively large compared to other types of insectivores: its length is 32 centimeters, its tail is on average 25 cm, the weight of the animal is about 1 kilogram, and its body is dense.


MANED WOLF. Lives in South America. Long legs wolves are the result of evolution in matters of adaptation to their habitat; they help the animal overcome obstacles in the form of tall grass growing on the plains.


AFRICAN CIVET- the only representative of the genus of the same name. These animals live in Africa in open spaces with high grass from Senegal to Somalia, southern Namibia and in the eastern regions South Africa. The size of the animal can visually increase quite significantly when the civet raises its fur when excited. And her fur is thick and long, especially on the back closer to the tail. The paws, muzzle and tail end are completely black, most of the body is spotted.


MUSKRAT. The animal is quite famous due to its sonorous name. It's just a good photo.


PROCHIDNA. This miracle of nature usually weighs up to 10 kg, although larger specimens have also been observed. By the way, the length of the echidna’s body reaches 77 cm, and this is not counting their cute five to seven centimeter tail. Any description of this animal is based on comparison with the echidna: the legs of the echidna are higher, the claws are more powerful. Another feature of the echidna’s appearance is the spurs on the hind legs of males and the five-fingered hind limbs and three-fingered forelimbs.


CAPIBARA. Semi-aquatic mammal, the largest of modern rodents. It is the only representative of the capybara family (Hydrochoeridae). There is a dwarf variety, Hydrochoerus isthmius, which is sometimes considered as a separate species (lesser capybara).


SEA CUCUMBER. HOLOTHURIA. Sea egg pods, sea ​​cucumbers(Holothuroidea), a class of invertebrate animals such as echinoderms. Species eaten as food are common name"trepang".


PANGOLIN. This post simply could not do without him.


HELL VAMPIRE. Mollusk. Despite its obvious similarity with octopus and squid, scientists have identified this mollusk as a separate order Vampyromorphida (lat.), because it is characterized by retractable sensitive whip-shaped filaments.


AARDVARK. In Africa, these mammals are called aardvark, which translated into Russian means “earthen pig.” In fact, the aardvark is very similar in appearance to a pig, only with an elongated snout. The structure of the ears of this amazing animal is very similar to that of a hare. There is also a muscular tail, which is very similar to the tail of an animal such as a kangaroo.

JAPANESE GIANT SALAMANDER. Today it is the largest amphibian, which can reach 160 cm in length, weigh up to 180 kg and can live up to 150 years, although officially registered maximum age giant salamander is 55 years old.


BEARDED PIG. IN different sources The bearded pig is divided into two or three subspecies. This is curly bearded pig(Sus barbatus oi), which lives on the Malacca Peninsula and the island of Sumatra, the Bornean bearded pig (Sus barbatus barbatus) and the Palawan bearded pig, which, as their name suggests, live on the island of Borneo and Palawan, as well as on Java, Kalimantan and small islands Indonesian archipelago in South-East Asia.




SUMATRAN RHINO. They belong to the odd-toed ungulates of the rhinoceros family. This type Rhinoceroses are the smallest of the entire family. Body length adult The Sumatran rhinoceros can reach 200 – 280 cm, and the height at the withers can vary from 100 to 150 cm. Such rhinoceroses can weigh up to 1000 kg.


SULAWESI BEAR COUSCUS. An arboreal marsupial living in the upper tier of the plains tropical forests. The fur of the bear cuscus consists of a soft undercoat and coarse guard hairs. Coloration ranges from gray to brown, with a lighter belly and limbs, and varies depending on the geographic subspecies and age of the animal. The prehensile, non-haired tail is approximately half the length of the animal and serves as a fifth limb, making it easier to move through the dense tropical forest. The bear cuscus is the most primitive of all cuscus, retaining primitive tooth growth and structural features of the skull.


GALAGO. Its large fluffy tail is clearly comparable to that of a squirrel. And his charming face and graceful movements, flexibility and insinuation, clearly reflect his cat-like traits. The amazing jumping ability, mobility, strength and incredible dexterity of this animal clearly show its nature as a funny cat and an elusive squirrel. Of course, there would be a place to use your talents, because a cramped cage is very poorly suited for this. But, if you give this animal a little freedom and sometimes allow him to walk around the apartment, then all his quirks and talents will come true. Many even compare it to a kangaroo.


WOMBAT. Without a photograph of a wombat, it is generally impossible to talk about strange and rare animals.


AMAZONIAN DOLPHIN. Is the largest river dolphin. Inia geoffrensis, as scientists call it, reaches 2.5 meters in length and weighs 2 quintals. Light gray juveniles become lighter with age. The Amazonian dolphin has a full body, with a thin tail and a narrow muzzle. A round forehead, a slightly curved beak and small eyes are the characteristics of this species of dolphin. Occurs Amazonian dolphin in rivers and lakes Latin America.


MOONFISH or MOLA-MOLA. This fish can be more than three meters long and weigh about one and a half tons. The largest specimen of the sunfish was caught in New Hampshire, USA. Its length was five and a half meters, there is no data on weight. The shape of the fish’s body resembles a disk; it was this feature that gave rise to the Latin name. The moon fish has thick skin. It is elastic, and its surface is covered with small bony projections. The larvae of fish of this species and young individuals swim in the usual way. Adult large fish swim on their sides, quietly moving their fins. They seem to lie on the surface of the water, where they are very easy to spot and catch. However, many experts believe that only sick fish swim this way. As an argument, they cite the fact that the stomach of fish caught on the surface is usually empty.


TASMANIAN DEVIL. Being the largest of modern predatory marsupials, this animal is black in color with white spots on the chest and rump, with a huge mouth and sharp teeth has a dense physique and a stern disposition, for which, in fact, he was called the devil. Emitting ominous cries at night, the massive and clumsy Tasmanian devil looks like little bear: the front legs are slightly longer than the hind legs, the head is large, the muzzle is blunt.


LORI. Feature lori – big size eyes, which may be bordered by dark circles, with a white dividing stripe between the eyes. The face of a loris can be compared to a clown mask. This most likely explains the animal's name: Loeris means "clown".


GAVIAL. Of course, one of the representatives of the crocodile order. With age, the gharial's muzzle becomes even narrower and longer. Due to the fact that the gharial feeds on fish, its teeth are long and sharp, located at a slight angle for ease of eating.


OKAPI. FOREST GIRAFFE. Traveling around Central Africa, journalist and African explorer Henry Morton Stanley (1841-1904) repeatedly encountered local aborigines. Having once met an expedition equipped with horses, the natives of the Congo told the famous traveler that they had wild animals, very similar to his horses. The Englishman, who had seen a lot, was somewhat puzzled by this fact. After some negotiations in 1900, the British were finally able to purchase parts of the skin of the mysterious beast from local population and send them to the Royal Zoological Society in London, where the unknown animal was given the name “Johnston's Horse” (Equus johnstoni), that is, it was assigned to the equine family. But imagine their surprise when a year later they managed to get a whole skin and two skulls of an unknown animal, and discovered that It looked more like a dwarf giraffe from the Ice Age. Only in 1909 was it possible to catch a living specimen of Okapi.

WALABI. TREE KANGAROO. The genus of Tree kangaroos - wallabies (Dendrolagus) includes 6 species. Of these, D. Inustus or the bear wallaby, D. Matschiei or Matchisha's wallaby, which has a subspecies D. Goodfellowi (Goodfellow's wallaby), D. Dorianus - the Doria wallaby, live in New Guinea. In Australian Queensland, there are D. Lumholtzi - Lumholtz's wallaby (bungari), D. Bennettianus - Bennett's wallaby, or tharibin. Their original habitat was New Guinea, but now wallabies are found in Australia. Tree kangaroos live in tropical forests mountainous regions, at altitudes from 450 to 3000m. above sea level. The body size of the animal is 52-81 cm, the tail is from 42 to 93 cm long. Wallabies weigh, depending on the species, from 7.7 to 10 kg for males and from 6.7 to 8.9 kg. females.


WOLVERINE. Moves quickly and deftly. The animal has an elongated muzzle, a large head, with rounded ears. The jaws are powerful, the teeth are sharp. Wolverine is a “big-footed” animal; its feet are disproportionate to the body, but their size allows them to move freely through deep snow cover. Each paw has huge and curved claws. Wolverine is an excellent tree climber and has keen eyesight. The voice is like a fox.


FOSSA. The island of Madagascar has preserved animals that are not found not only in Africa itself, but also in the rest of the world. One of the rarest animals is the Fossa - the only representative of the genus Cryptoprocta and the largest predatory mammal living on the island of Madagascar. The appearance of the Fossa is a little unusual: it is a cross between a civet and a small puma. Sometimes the fossa is also called the Madagascar lion, since the ancestors of this animal were much larger and reached the size of a lion. Fossa has a squat, massive and slightly elongated body, the length of which can reach up to 80 cm (on average it is 65-70 cm). The fossa's paws are long, but quite thick, with the hind paws being higher than the front paws. The tail is often equal to the length of the body and reaches up to 65 cm.


MANUL approves of this post and is here only because he has to be. Everyone already knows him.


PHENEC. STEPPE FOX. He assents to the manula and is present here insofar as. After all, everyone saw him.


NAKED MORAVARY gives the Pallas's cat and fennec cat pluses in their karma and invites them to organize a club of the most fearful animals in RuNet.


PALM THIEF. Representative of decapod crustaceans. The habitat of which is West Side Pacific Ocean and tropical islands of the Indian Ocean. This animal from the family of land crayfish is quite large for its species. The body of an adult reaches a size of up to 32 cm and a weight of up to 3-4 kg. For a long time it was mistakenly believed that with its claws it could even split coconuts, which he then eats. To date, scientists have proven that crayfish can only feed on already split coconuts. They, being its main source of nutrition, gave the name palm thief. Although he is not averse to eating other types of food - the fruits of Pandanus plants, organic substances from the ground and even their own kind.

“The protruding parts of the bodies of warm-blooded animals (ears, legs, tails) are smaller in cold climates than in warm climates.”

Explanation: The larger the ears and tails, the larger the body surface through which heat escapes. This is not beneficial for northern animals, which is why their ears and tails are small. For southern relatives, on the contrary, it is convenient to have a large surface in order to somehow cool down.

Explanation: when an organism increases in size, its volume increases and its surface area increases - everyone grows, but at different speeds. The surface lags behind - grows slower than volume, therefore the surface of large northern animals is relatively small. They need this for the same thing - to give off less heat.

Example: polar Wolf- the largest of all wolves, the polar bear - of all bears, wolverine - of all mustelids, elk - of all deer, wood grouse - of all grouse.

Why do such large animals as elephant and hippopotamus live in the south?

Because there is enough vegetation there for them to feed themselves. - But at the same time they Very hot. The hippopotamus constantly sits in the water, the elephant cools itself with the help of its huge ears. (Mammoths that lived in temperate climate, were the same size as modern elephants, but at the same time had normal size ears and fur, as befits mammals.)

Herbivores living in the north are larger than their southern relatives because northern grass has greater nutritional value, scientists say. The unexpected explanation of Bergmann's rule was confirmed experimentally.

Karl Georg Lucas Christian Bergmann - German biologist, physiologist and anatomist, for a long time studied comparative anatomy. But it was the description of the ecogeographical pattern that brought him fame, which was later named after him. Famous phrase from Bergman’s book “On the connection between the economy of heat in animals and their size,” which was published in 1847, it sounds like this: “If there is a genus whose species differ only in size, then more small species this genus will gravitate toward warmer climates, and in exact accordance with their mass.”

How does Bergman's rule work?

Many scientists indeed confirm that such a pattern exists. True, the question “why” remained unanswered for a long time. Now scientists explain this pattern by the peculiarities of thermoregulation of warm-blooded animals. The fact is that heat production is proportional to the volume of the body, and heat transfer is proportional to its surface area. Accordingly, the surface area to volume ratio is smaller in larger animals. Therefore, in cold northern latitudes Ah, it’s more profitable to be large in order to produce more heat and give it away less, but in the southern regions it’s the other way around.

Dr. Chuan-Kai Ho from the University of Houston, together with his colleagues, proposed a completely new and unexpected explanation for Bergmann's rule, which, however, will undoubtedly raise many more questions among scientists. Dr. Ho, although not excluding the traditional explanation, suggested that the body size of animals largely depends on what kind of food they eat. According to Dr. Ho's hypothesis, the vegetation of northern latitudes has greater nutritional value, so the herbivores that eat these plants differ more large sizes bodies.

Northern plants are more nutritious

Scientists decided to test Dr. Ho's assumption experimentally. The experimental samples were widely distributed insects. Prokelisia from the suborder of pectoral proboscis ( Archaeorrhyncha) and the clam Aplysia ( Aplysia) (sea hare). According to scientists, although these species are cold-blooded, Bergmann’s rule also works in their example - the largest specimens are found in more northern latitudes, and the smallest in southern latitudes.

Insects and mollusks were raised in laboratory conditions, and fed exclusively on plants Spartina anglica. Scientists collected the plants themselves at different latitudes North America(in the tundra and forest zones). Through certain time When the shellfish and insects reached maturity, Dr. Ho measured their body sizes. According to the authors of the work, insects that received grass grown in the tundra were 8% larger than their relatives that fed on grass from the temperate zone. As for mollusks, the size of individuals that fed on northern grasses turned out to be as much as 27% larger. There can be only one explanation for this – different nutritional value herbs growing in different conditions, says Dr. Ho.

“We do not believe that this is the only possible explanation for Bergmann's rule. But our research shows that to explain the mechanism of its operation, it is not enough just to know the characteristics of physiological reactions to different temperatures environment. It is also important to take into account the ecological relationships of animals with their environment,” says Dr. Ho.

Scientists still find it difficult to answer why plants growing at high latitudes are more nutritious and are only making assumptions. One of the authors of the study, Dr. Stephen Pennings, in his previous works, showed that plants in northern latitudes are less susceptible to attacks from insects. Perhaps this is why, the authors of the work suggest, southern plants spend more energy on chemical protection against insects, and their lower nutritional value is also a kind of protective mechanism against voracious insects.

Dr. Ho's article "Is Diet Quality an Overlooked Mechanism for Bergman's Rule" can be found in the February issue of The American Naturalist.