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Scientists have sequenced the complete genome of a koala for the first time and analyzed more than 26 thousand active genes, according to Nature genetics... This allowed scientists to understand why marsupials can eat poisonous eucalyptus leaves without harm to themselves, how they chose a suitable diet for themselves, and how they learned to protect young and adults from infections.

Koala ( Phascolarctos cinereus) today the only representative of the koala family that lives in Australia. Koalas are the closest relatives of wombats, their common ancestor lived about 30-40 million years ago. In ancient times, there were 15-20 species of these animals on the continent, and the existing species appeared about 350 thousand years ago. Today, three subspecies are known. One of them lives in Queensland, in the northeast of the continent, the other two - in the south and southeast of the country. Previous studies (true, more than 20 years ago) have shown that two of the three subspecies have low genetic diversity and a high percentage of closely related crosses.

The female koala gives birth to an underdeveloped cub after 35 days of pregnancy, and the baby spends the next six months in the mother's brood pouch. Koalas are very selective in their food: they feed almost exclusively on eucalyptus leaves, and out of 600 species of eucalyptus, they prefer about 30. Animals get almost all water from the leaves, therefore they include in their diet those types of eucalyptus, the leaves of which contain at least 55 percent of water. Since the leaves are low in calories, animals need to eat up to 400 grams of leaves a day and save energy. They sleep about 20 hours a day, and eat most of the remaining four hours. Eucalyptus leaves are not a very attractive food, not only because of their low calorie content. They contain compounds that are extremely toxic to most other animals. Koalas have adapted to them, and thus practically avoided food competition. However, how they adapted to poisonous food, and how they differentiated suitable trees among the huge variety of eucalyptus species, was still unclear.

To answer these and other questions (for example, how koalas protect themselves from infections and how the species can be preserved in the future), scientists from the Koala Genome consortium sequenced the complete genome of the marsupial bear. The research team, currently 54 scientists from seven countries, led by Dr. Rebecca Johnson, began work in 2013 and has already published some of the results.

In the new work, scientists present directly the results of genome sequencing and analysis of 26,558 active genes that make up it. The genome of koalas turned out to be larger than a human (3.42 versus 3.2 billion base pairs), but consists of a smaller number of chromosomes (16 versus 23 pairs).

Scientists have discovered how marsupials have adapted to their poisonous diet. They turned out to have much more genes than other animals that encode proteins from the cytochrome P450 family. These enzymes oxidize various substances, converting them into water-soluble metabolites, which are quickly excreted in the urine. It turned out that in koalas, cytochromes are produced in many tissues, including the liver. However, the defense also had a downside - cytochromes quickly break down antibiotics given to sick koalas.

Genes also helped explain the ability of animals to recognize the desired types of eucalyptus. Koalas have 24 genes responsible for recognizing bitter taste - the largest number among Australian marsupials. In addition, they turned out to have six genes encoding vomeronasal receptors that can capture the smell of not too volatile substances. For comparison, the marsupial devil and the gray short-tailed possum have one such gene, while the platypus and wallaby do not have them at all. Koalas are also able to sense the "taste of water" - to recognize the water content in eucalyptus leaves. They learned this by increasing the genes for the protein aquaporin 5, which forms pores in the cell membrane through which water enters cells.

Researchers have found that koalas protect babies from infections while they sit in the pouch by using breast milk. It contains enzymes specific only to koalas with antimicrobial activity. They protect young animals from a range of bacterial and fungal infections, including chlamydia Chlamydia pecorum, which cause diseases of the eyes and genitourinary system. Adult koalas are saved from infections with the help of numerous proteins of the immune system - immunoglobulins, proteins of the main histocompatibility complex, T-lymphocytes.

In addition, scientists found new genetic markers and, with their help, made sure that the subspecies, which, according to old research, had low genetic diversity and a high percentage of closely related crossbreeding due to population isolation, in fact mix with each other and their genetic diversity is quite high.

More details about the habits and personal life of koalas Zhenya Timonova in one of the issues "Everything is like animals."

Ekaterina Rusakova

Now koalas live only in Australia - and then not everywhere, but only in the southeastern part of the continent. Outwardly, they resemble small bear cubs: sedentary with thick, short hair of a gray-smoky or reddish color, small round, half-blind eyes, a flattened oval nose, short tail and large wide-set ears with long hair around the edges.

It is now koalas are one of the symbols of Australia, and once European settlers quickly pushed them out of Australia and at the same time almost destroyed because of the rare beauty of their soft fur coat with three centimeters of fur. But these animals appeared on the mainland more than 30 million years ago, and according to the beliefs of local aborigines, they were also once people.

How the animal appeared: the Aboriginal version

Ancient legends of local aborigines tell about an orphan boy Kub-Bor (Marsupial Bear), who, although raised by his closest relatives, did not like him very much, therefore he was constantly offended. The boy was taught to survive in the forest and get food. Therefore, he had no problems with food, but with water it was difficult, since Kur-Bor was constantly thirsty.

When one day all the adults went to hunt and collect food, forgetting to hide the buckets with water, a child saw them - and gradually drank all the contents, leaving the tribe without water. After that, he climbed onto the eucalyptus and began to sing a song monotonously, from which the tree, on the top of which he was sitting, began to grow extremely rapidly, and by evening it turned out to be the largest in the entire forest. And then the Daens (aborigines) returned.

They did not find water, but they found a child hiding on a huge eucalyptus. At first they could not reach Kur-Bor, since the branches of a huge tree were extremely high. But then two of them managed to climb the tree. The boy was captured by them, beaten right at the top of the tree, and thrown down.

Naturally, Kur-Bor crashed to death. But when the natives approached him, they saw that the boy gradually began to turn into a koala. After completing the transformation, the animal came to life, rushed to the eucalyptus and climbed up.

The last words that the daeny heard from the koala was that if he and his kind were killed in order to eat, it would only be necessary to cook it whole. If someone disobeys, his spirit will come out of the carcass of the killed beast and cruelly punish the guilty ones - such a drought will come that neither people nor animals can survive it. Only koalas will survive, for which there will be enough moisture, which is contained in the leaves of the eucalyptus.


The koalas themselves, according to the beliefs of the aborigines, have not drunk water since then. Their ancestor, being a human, drank enough of it. This belief arose for one simple reason: before, almost no one had ever seen these animals at a watering hole.

Scientists' version

It is believed that the family of koalas appeared more than 30 million years ago, and numbered at least eighteen species (some of which were thirty times larger than koalas). As for the "modern" animals, they are much younger. Their age is only 15 million years.

Europeans discovered this animal at the beginning of the 19th century. These were the remains of a koala found among the natives. Officer Barralier, who found them, instilled them in alcohol and sent them to the governor of New South Wales. A year later, not far from Sydney, the animal itself was caught.

At first, koalas were found only in the southeast of Australia, as well as in the south of the continent (but there they were quickly exterminated in the early 20th century in pursuit of profit). It is believed that these animals lived in the west of the mainland, as evidenced by the remains found there.

Species characteristic

Scientists have still not really been able to determine what type of animal the animal that lives in Australia belongs to. At first they thought that it was a panda or a bear, then they decided that his relative was a wombat, kangaroo or possum (all of them, like the koala, are herbivorous marsupial animals). But if the relationship still exists, then the researchers have not yet been able to trace their roots.



Features of the animal

The koala itself is a medium-sized animal. The weight of a large male from the southern part of the continent is about fifteen kilograms, a female from the north is ten kilograms less. The average length of an adult koala is about eighty centimeters.

The marsupial sleeps in trees for about twenty hours a day. It is active at night, climbing the tops in search of leaves. During the day, even if the animal is awake, it sits motionless or sleeps, embracing the eucalyptus with its paws.


The animal has interesting characteristics that distinguish it from other animals, because of which it was attributed to a separate species.

Paws

The koala's paws are ideal for climbing trees and allow an adult to grasp tree branches without problems, and a baby to hold on to its mother's back. The animal sleeps only on eucalyptus, tightly clasping the tree with its paws:

  • The koala has two grasping fingers on its front legs, located slightly away from the rest;
  • The other three fingers are along the hand;
  • All fingers on the forelimbs have extremely strong claws;
  • The thumb on the foot of the koala has no claw (unlike the other four).
  • All koala fingers have fingerprints that are extremely human-like.

Teeth


The animal's teeth are designed to chew the grass. Therefore, their incisors are like a razor and are able to quickly cut leaves. The rest of the teeth are grinding; a wide gap separates them from the incisors.

Intelligence and ingenuity

Alas, modern koalas are stupid. If the brain of their ancestors completely filled the cranial cavity, then in the animals that have survived to this day, it is much smaller. According to one theory, this was due to the fact that koalas mainly feed on eucalyptus leaves and shoots, which contain an extremely low level of energy.

Therefore, the brain of modern koalas is only 1.2% of their total weight, and forty percent of the cranial cavity is filled with cerebrospinal fluid. Lack of intelligence negatively affects the life of the animals themselves. For example, accustomed to looking for salvation in trees, they do not always consider it necessary to get off them and escape from the fire. Instead, they only nestle tighter against the eucalyptus trees.

Character

Koala is an extremely calm animal. He sleeps from 18 to 20 hours a day, the rest of the time he devotes to food. The koala lives in a tree, and descends to the ground mainly in order to move to another eucalyptus, to which it is not able to jump through the air.


From eucalyptus to eucalyptus, they jump extremely easily and confidently. If they have already decided to flee, then they are even able to go into a rather vigorous gallop in order to climb the nearest tree.

Nutrition

As for the slowness of the koala not in emergency conditions, this is primarily due to its nutrition. It feeds only on shoots and leaves of the eucalyptus tree. The metabolism of a koala is twice as slow as that of other mammals (except for wombats and sloths) - this feature compensates for the insufficient nutritional value of eucalyptus leaves.


The question of why koalas prefer eucalyptus leaves baffles many. Because eucalyptus leaves are not only fibrous and low in protein, but they also contain phenolic and terpene compounds and even hydrocyanic acid, which are extremely toxic to almost all living organisms.

As for koalas, the deadly poisons that enter the bloodstream from the intestinal tract are completely rendered harmless by the liver. The animals have a very long cecum - almost two and a half meters (in humans - no more than eight centimeters). It is in it that poisonous food is digested. There are many bacteria in the intestines of koalas that convert the leaves into compounds that are digestible for the koala.

The animal eats about one kilogram of leaves per day, while crushing and chewing them very carefully. And what is interesting, the resulting mass is stored in cheek pouches.

Koalas do not eat leaves from every tree: their extremely good scent allows you to choose only those plants where there are fewer poisonous compounds. Therefore, out of eight hundred species of eucalyptus, koalas eat only one hundred and twenty. And then, when their nose tells them that the food has become too poisonous, they go to look for another suitable eucalyptus for themselves (if koalas did not have the opportunity to change the tree in time, they often became victims of poisoning).

They give preference to trees that grow on fertile land - they are less poisonous. To compensate for the lack of minerals in the body, animals sometimes eat earth.

Eucalyptus leaves for a koala are also a source of moisture. They drink water mainly during a drought or when they are sick. In Australia, more and more often these animals are found near their pools, when they come to drink water.

Temperature

Koalas do not have a layer of subcutaneous fat to protect them from the cold. Firstly, if the temperature is too low, wool helps them out (their fur is water-repellent), and secondly, in order to keep warm, their blood circulation, like that of humans, slows down.

Communication

Koalas are considered almost the most defenseless and harmless animals in the world. They do not attack anyone and absolutely do not know how to protect themselves. If you hurt them, they will run away at best, and most likely will not hit back and bite.

But this animal can cry. And he can cry as long as the pain causes him inconvenience. And the koala is crying like a child - loudly, trembling and hysterically. The same sound can also symbolize the presence of danger.


Koalas are surprisingly silent. Since they live rather far from each other, in order to communicate with their own kind, they use a fairly wide range of sounds.

Males, in order to show their social and physical status, grunt in a peculiar way, and thus find out which of them is cooler (they are not going to spend strength and energy on fights, and if this happens, it is quite rare). Females scream much less often, but sometimes they can express aggression by roaring-grunting, and they also use this sound to express sexual behavior. But mothers and their cubs do not roar - they make quiet, stilted sounds, reminiscent of clicking (to "talk to each other") or grunting (if they are dissatisfied or annoyed with something).


Screams during the mating season

When the mating season begins, males give such a loud calling sound that you can hear it for a kilometer. It is interesting that this sound is extremely loud and at the same time at a low frequency, which is not typical for small animals the size of a koala. They manage to publish it only with the help of the vocal cords behind the larynx.

The female chooses a groom for herself, proceeding precisely from such call-up calls (in any case, preference is given to larger individuals). Despite the fact that the songs of the male remind us of the snoring of a drunkard, the angry grumbling of a pig or the creak of rusty hinges, the females are extremely fond of such sounds and attract them.

The better the koala cries, the more brides it will collect, since there are much more females than males. In one season, one male can have about five wives.

Offspring

Koalas breed once every one to two years. Females create a family at the age of two, males at the age of three or four.

The mother carries the cub from thirty to thirty-five days. Usually only one baby is born, twins are extremely rare. The length of a small koala is from 15 to 18 mm, weight is about five grams, while he is hairless and completely blind. Immediately after birth, the baby is taken into the mother's bag, where he spends the next six months. To prevent the baby from getting hurt and falling out, the "entrance" to the bag is not located at the top, like in a kangaroo, but below.


First, he feeds on breast milk. It weaned from it gradually, and the transitional food is quite original: the mother regularly excretes special feces in the form of a liquid porridge from half-digested eucalyptus leaves. Such food is necessary for the baby, since this is the only way to get the microflora he needs, since bacteria live in the mother's intestines, which help the body to cope with food indigestible for the baby's stomach.

True, such a diet does not last long, after a month he begins to feed on the leaves themselves, and at the age of seven months he moves from the pouch to the mother's back. Finally, the grown koala leaves the maternal embrace in a year. But not all leave: while young females go to look for plots for themselves, males quite often remain to live with their mother for up to three years.


Dangers

Usually, the koala lives from eight to thirteen years (although in captivity there are cases when the animals lived to be twenty). Their number for some time (until the Australian authorities took up the solution to this problem) very quickly decreased. If at the beginning of the 20th century the number of koalas was 10 million individuals, then after a hundred of them only 100 thousand remained, most of which live in private territories. According to various sources, in the wild, only 2 to 8 thousand of them live.

In nature, koalas have practically no enemies - apparently, the animal impregnated with a eucalyptus aroma scares off enemies with its smell. Only people eat them, and wild dingo dogs can attack from animals, but this is also a rare occurrence, because koalas rarely go down, and dogs do not jump on trees.


More recently, these animals were on the verge of extinction. The main reason is human activity, as well as their extreme tendency to various diseases.

Diseases

Koalas are quite painful animals - apparently, the monotonous diet affects. They are especially susceptible to cystitis, periostitis of the skull, conjunctivitis. Sinusitis often causes pneumonia in them, which severely reduced the population at the beginning of the last century.

Animals are also killed, and the viral bacteria Chlamydia Psittaci, which is tacitly considered the "AIDS" of koalas. They infect the ureter and eyes of animals, and if they are not helped in time, the disease will first lead to infertility, then - to vision problems, and in the end to death.

Fur traders

Even before the beginning of the 20th century, a huge number of koalas (more than one million) were destroyed by fur traders, after which there were almost no animals left. And only then (in 1927) the Australian government banned the trade in koala fur, and three years later - to import their skins. This led to the end of the barbaric extermination of koalas, and their population began to gradually increase.

Deforestation

Due to the continuous deforestation, koalas are forced to constantly go in search of new trees, so they have to go down. And they are not accustomed to life on earth, since they move here with difficulty, therefore they become easy prey.


Cars

In connection with the deforestation, koalas in search of a new home are increasingly found on the tracks. Cars rushing at high speed frighten them extremely, animals freeze (the so-called "koala syndrome" - males are especially susceptible to it) and stop moving or begin to rush along the road. According to statistics, about 200 koalas are under the wheels of cars every month - and, unfortunately, many of them die in the process.

At the same time, the authorities are trying to solve this problem in a rather interesting way: they stretch artificial vines over the highway, which connect the eucalyptus trees on both sides of the highway. This idea is appreciated by koalas and are eagerly crossing the freeway.

Dogs


Once on the ground and seeing a wild dog dingo, the koala does not understand all the danger and does not run away to the tree. As a result, it often turns out to be torn to pieces.

Fires

The trees, on which koalas love to live, contain eucalyptus oil, thanks to which fires flare up extremely strongly and cannot be extinguished for a long time. The fire has completely destroyed more than one population of koalas.

Pools

Many will be surprised to learn how many koalas die when they get into the pool. Contrary to popular belief that they drink absolutely nothing, they still come to the watering hole, but often not to the source, but to a structure created by human hands, which does not have the usual descents for animals. Despite the fact that they are great at swimming, koalas often drown, exhausted.

Drought

Due to drought, eucalyptus leaves turn black and dry out, so koalas deprived of water often die of thirst, especially those who live far from artificial or natural sources of water.

Animal rescue

If the inactive activity of animal defenders, we would only know about the koala from the schematic drawings of their textbooks. They managed not only to push through several laws to protect these animals, but also to attract patrons of the arts who are willing to donate money to save the "teddy bears".


In Australia, parks and reserves have been created, special hospitals have been organized for these animals with the latest equipment and highly qualified veterinarians. This is not much, but it helps - about 4 thousand animals are saved a year. About twenty percent of the animals that fall into the hands of doctors survive.

Life in captivity

As already mentioned, most koalas live in private estates, the owners of which have nothing against such a neighborhood. People are often captivated by the appearance of these cute fluffy animals, similar to teddy bears, and they tame them. Koalas, although they love solitude, are extremely friendly. They become attached very quickly, and if the person to whom they are accustomed leaves somewhere, then the animal cries. If you stick to them too much, koalas can begin to defend themselves with their teeth and nails.


Keeping a koala at home is not easy - those who want to have this animal every day will be required to provide it with at least one kilogram of fresh eucalyptus leaves per day, which is quite difficult. For example, in Russia, these trees grow only in Sochi, but this type of eucalyptus is absolutely not suitable for koalas.

Koala - Every day the koala eats about one kilogram of eucalyptus leaves.

eucalyptusaurus ...

Eucalyptus leaf eater

Marsupial bear KOALA Australia

Bear KOALA

probably everyone knows it-koala

Lifestyle and nutrition

Koala with baby

Koalas inhabit eucalyptus forests, spending almost their entire life in the crowns of these trees. During the day, the koala sleeps (18-22 hours a day), sitting on a branch or in the forks of branches; climbs trees at night, looking for food. Even if the koala does not sleep, he usually sits completely motionless for hours, clasping a branch or tree trunk with his front paws. He descends to the ground only to go to a new tree, to which he cannot jump. Koalas jump from tree to tree with surprising dexterity and confidence; fleeing, these usually slow and phlegmatic animals switch to an energetic gallop and quickly climb the nearest tree. They know how to swim.

The slowness of the koala is associated with the peculiarities of its nutrition. He has adapted to eat almost exclusively on shoots and leaves of eucalyptus, which are fibrous, contain little protein, but a lot of phenolic and terpene compounds, poisonous to most animals. In addition, young shoots, especially closer to autumn, contain hydrocyanic acid. Due to their toxic properties, food competition from other animals in the koala is extremely small - besides it, only the ring-tailed possum Pseudocheirus peregrinus and the flying marsupial Petauroides volans feed on eucalyptus leaves.

In order not to be poisoned, koalas choose for food only those types of eucalyptus that contain fewer phenolic compounds, and prefer trees growing on fertile soils (especially along river banks), in whose leaves the concentration of poison is lower than that of eucalyptus growing on poor, infertile lands. As a result, out of 800 species of eucalyptus, koalas feed on only 120 species. Apparently, a developed sense of smell helps to choose the right food for koalas. In captivity, where the animal usually has less choice, it is even capable of food poisoning as a result of the cumulative effect.

Koala eating eucalyptus leaves

The metabolic rate in the body of a koala is almost half that of most mammals (with the exception of wombats and sloths) - this helps him to compensate for the low nutritional value of the diet. On a day, a koala needs from 0.5 to 1.1 kg of leaves, which he carefully crushes and chews, accumulating the resulting mass in the cheek pouches. Like all mammals that eat fibrous plant foods, koalas have a rich microflora in the digestive tract, including bacteria that convert indigestible cellulose into digestible compounds. The cecum, where the digestion process takes place, is extremely developed, reaching a length of 2.4 m. Poisonous substances, getting into the blood, are neutralized in the liver.

"Koala" in the language of the tribes of New South Wales means "do not drink" - the koala receives all the necessary moisture from the leaves of eucalyptus trees, as well as from the dew on the leaves. They drink water only during periods of prolonged droughts and during illness. To make up for the lack of minerals in the body, koalas eat the earth from time to time.

There is no natural regulator of the number of these animals in nature - aboriginal predators do not hunt them; only dingoes and feral dogs attack koalas. But koalas are often sick. Cystitis, periostitis of the skull, conjunctivitis, sinusitis are their common diseases; sinusitis often leads to pneumonia, especially in cold winters. Epizootics of complicated sinusitis, which greatly reduced the number of koalas, took place in 1887-1889 and in 1900-1903.

The slowed down world of koalas and sloths

They are in no hurry. While antelopes race across the savannah, squirrels and weasels flash among the branches, and kangaroos race along the bush with a stomp, these animals always spend their time half asleep in the crowns of trees.

Sometimes koalas can seem very nimble. For example, when fighting dogs or during mating games. At such moments, Australian "teddy bears", suddenly showing agility that does not match their appearance at all, look amazingly unusual.


But most of the time they spend alone, sleeping or sitting completely motionless, moving only their jaws. The life of koalas drags on slowly and monotonously. This is the price to pay for the opportunity not to compete for food resources, feeding on poisonous eucalyptus leaves.

Eucalyptus leaves are bad food. There is almost no protein in them, they are tough and fibrous, and, worst of all, they contain a lot of toxic phenols and terpenes (the main components of resins and essential oils), coumaric and cinnamic acids, and hydrocyanic acid is also present in the leaf stalks. But this resource, although not nutritious, is extremely extensive, because eucalyptus trees, being very unpretentious trees, form forests even where other trees do not survive. It would be strange if such a food source did not attract any "gastronomic extreme".

Only 120 of the more than 700 species of eucalyptus, the least poisonous, are suitable for koalas, and in order to distinguish edible leaves from others, animals have resorted to an unusually developed sense of smell. Since all eucalyptus trees belong to the same genus, their smells are very similar, and koalas try to eliminate the slightest mistake.

If you hold the leaves edible for koalas in your hands, and then offer them to the "teddy bears", they will not eat them: the smell differs from the reference one, and the animals will not take risks. Many cases are associated with such "stubbornness" when koalas died in captivity, refusing food, which they definitely ate in freedom, but which for some reason acquired an uncharacteristic smell.

Although the diet of koalas is rich in essential oils, runny nose in these animals is not uncommon: they often suffer from inflammation of the sinuses, from which many die, especially in cold winters. It even comes to an epizootic of a respiratory tract infection.


So why is the koala world so slow? Due to the fact that eucalyptus leaves are poisonous, you cannot eat a lot of them so that toxins do not accumulate in the body in large quantities. During the day, a koala rarely eats more than half a kilogram of leaves, which is not much for a herbivore weighing more than 10 kilograms. But, since the leaves are not nutritious, you need to assimilate them as best as possible so that nothing useful is lost.

As a result, the koala eats slowly, digests slowly, and its entire metabolism is extremely inhibited. The leaves are chewed very carefully, rubbing into a gruel that accumulates in the cheek pouches, where it undergoes primary processing with enzymes contained in saliva.

Then it enters the stomach, and from there into the intestines. Its section, which serves for the processing of coarse fibrous food, is the cecum, part of which has been reduced in our appendix, in koalas it reaches two and a half meters in length. Here, symbiotic bacteria decompose cellulose, and this is a long and energy-consuming process. To save energy, the animal sleeps most of the day -16-20 hours.

What are these marsupial "bears" doing when they are awake? Mostly food, because they even drink only in drought or during illness, usually making do with the moisture contained in the leaves. These cute creatures, alas, are not very interesting for the observer, because, adapting to a low-calorie and toxic diet, they sacrificed a lot, including the size and complexity of the brain, and therefore the complexity of behavior.

The brain is an extremely "expensive" organ in the energy sense, it is not easy to feed it, because it consumes up to 20% of the energy received by the body. Therefore, for animals, when possible, it is more beneficial to reduce the size of the brain. A similar thing happened even with humans: in the period from 25 to 10 thousand years ago, our brains shrank by more than 100 cubic centimeters.



In koalas, which, like all marsupials, have never been particularly intelligent (marsupials lack the corpus callosum connecting the cerebral hemispheres), the brain has shrunk so much that almost half of their skull is occupied by cerebrospinal fluid. In the brain itself, only the olfactory lobes are perfectly developed, and everything else is tiny. As a result, koalas sit in trees for most of their lives and do nothing at all. They are non-social, silent, they actively communicate with their own kind only during the mating season, when males mark their territory, fight with rivals and collect a harem of several females.

Mating games take place right on the tree and look very funny. At the end of the breeding season, the harems disintegrate, and after a month of pregnancy, the females give birth, as is customary for marsupials, "underdeveloped" cubs, which are worn out in a bag for another six months.

To digest eucalyptus leaves, the baby koala must acquire the appropriate intestinal microflora, which does not appear by itself. Cubs lick off the mother's excrement, which changes for about a month, turning into a slurry of semi-digested leaves containing cultures of bacteria necessary for the baby. Growing up, a baby koala leaves its mother and begins to lead an independent life - monotonous and slow, but lasting for 15 or even 20 years.

Surprisingly, even after a collision with a person, such a defenseless creature still thrives. Even despite the fact that in the XIX - early XX century koalas were massively exterminated by hunters (and to hunt animals that are not afraid of anyone, do not run away and do not hide, is easy), harvesting up to two million skins a year, until 1927 th, when hunting for them was prohibited. Of course, in the modern world, many dangers await these animals. For example, ticks imported by chance from Japan.



And when, during the mating season, koalas descend from the trees and actively move along the ground, they risk being hit by a car while crossing the highway or catching the eye of dogs, who will not miss the opportunity to hunt such an animal. Even though the koala meat is completely inedible, which reliably protected it from local predators. Many enthusiasts are involved in the rescue of injured koalas, who take them to special centers or to ordinary veterinary clinics.

The closest relatives of koalas, wombats, also have a slow metabolism, but live on the ground and are less picky about food.

LAZY SYMBIOSIS MASTERS

Much north of koalas, in South America, there are creatures with an equally slow metabolism. These are two-toed and three-toed sloths. Living surrounded by numerous predators, not constrained by a rigid diet, they nevertheless preferred the non-action praised by the Taoists. The lifestyle of sloths is in many ways similar to that of koalas. For more than half a day, sloths sleep, completely relaxed, hanging on the branches of trees, on which they are held with the help of long curved claws, outwardly (and functionally) similar to the “claws” of installers and rural electricians.



It is striking that the "hang and do not shine" strategy allowed sloths, which feed both jaguars and harpy hawks and other hunters for seemingly easy prey, to breed so much that in some areas of their habitat the biomass of sloths is two-thirds of all biomass mammals. There are sometimes over 750 sloths per square kilometer of rainforest. This is incredible density for large mammals! Animals hang motionless in the crowns of trees, merging in color with the foliage, and predators simply do not notice them.

Sloths have four times less skeletal muscle than other mammals of the same size. This is both a plus - less energy is spent on maintaining muscles, - and a minus: once on the ground, "weaklings" - sloths can neither offer anyone real resistance (although sometimes they scare off enemies, hissing and waving their long clawed paws), nor escape , especially since they are not able to walk normally and step on the outer part of the claws.



Once upon a time, sloths were a thriving family, most of which were diurnal (as opposed to the current, active at night) and highly mobile animals. Megatheria, the ancestors of modern sloths, were three meters tall and weighed half a ton. However, everyone died out, except for those who made secrecy and hypodynamia a strategy of survival.

The adaptation of sloths to a sedentary hanging lifestyle has affected their entire anatomy and physiology. Their brains, like those of koalas, are relatively small (although much larger: after all, sloths are placental mammals, not marsupials), the convolutions are strongly smoothed, only the olfactory parts of the brain are well developed.

Like koalas, sloths do not drink water, content with licking dew. Internal organs are displaced, for example, the liver is attached to the back. Unlike all other mammals, in sloths, the number of cervical vertebrae is not necessarily seven, but can go up to nine. A large number of cervical vertebrae will give the animal the ability to tear off foliage over a larger area, moving only its head.

The body temperature of sloths is unstable, on cool nights they cool down to 12 ° C, and on a hot day they can heat up to 35 ° C without harm to health. Sometimes they gather in groups for warmth and hang, huddled together. In the same place, it is believed, and mate. Unlike koalas, sloths eat a variety of plants, and not only foliage, but also buds, flowers, young shoots.

Like most herbivores, they do not refuse protein food, if they are lucky enough to feast on insects or lizards. And in times of famine, they can even feed on algae that live in their wool.

Blue-green photosynthetic algae are normal, of course, not a supply of food, but camouflage. The greenish fur, which grows in sloths not from front to back, but vice versa (that is, stroking the animal with the usual movement from head to tail, you stroke it against the fur), perfectly disguises the animal, making it almost invisible in the crown of the tree. In addition to algae, they also have other symbionts. The sloth, like the koala, cohabitates mutually with the abundant intestinal flora.




And in his wool (and only there) moth butterflies settle Bradipodicola hahneli... Adult insects feed on algae, and larvae develop in sloth excrement. For reasons not entirely clear, these animals relieve themselves only on the ground, where they descend about once a week (they have a huge bladder). For excrement, the sloth digs a hole at the roots of the tree on which he lives and fertilizes it with his feces, thus entering into a kind of symbiosis with the tree. It is a pity that the number of these mammals is declining. This happens due to the clearing of tropical forests, in which sloths feel at ease, but outside their limits they cannot exist.

Alas, sloths also have such cohabitants, without which they themselves, and we, people, could well do. These are the simplest, causative agents of leishmaniasis - a dangerous disease.

Why, if both sloths who live up to 30 years (longer than other mammals in the same places) and koalas thrive in their slow world, almost no one followed suit? Why do other mammals prefer to be swift and dexterous, despite the high "energy cost" of an active lifestyle? In order to allow yourself to live slowly, with atrophied muscles and a weak brain, you need to get into a very unusual situation. One where giving up the pursuit of speed would be beneficial.



For example, it will provide an opportunity to master an unclaimed food base, without risking becoming someone's prey, or, taking advantage of the symbiosis with algae, to hide from predators who will not be able to notice a motionless green animal in the foliage. Such lucky coincidences are probably extremely rare, and those who tried to get out of the "race for speed" without such favorable initial prerequisites disappeared, leaving no descendants.

Magazine Discovery January 2013

The level of awareness of the medicinal, nutritional and cosmetic properties of eucalyptus is extremely low. Every ordinary citizen knows that eucalyptus is the main dish in the diet of pandas, but no one has heard about the antioxidant and antibacterial effects of the plant. Few people imagine the real type of eucalyptus and its potential strength.

Let's figure out what a plant really is and is it worth spending time to learn more about it?

general characteristics

Eucalyptus is an evergreen woody plant (grows as a shrub or tree), belongs to the myrtle family. The tree is capable of reaching 100 meters in length. The trunk develops straight, less often - curved, covered with gum secretions. From the trunk, massive leaf plates grow, standing with an edge. The leaves are always located in the same plane with the branch, so they practically do not cast shadows. Each leaf goes through 3 stages of maturation (development) before giving a flower.

Australian eucalyptus is a compass plant. The plane of the sheet is located exactly along the meridian. Its edges (edges) are directed to the north and south, and the leaf plane is directed to the east and west.

The flowers are formed regular, sessile, collected in small protected inflorescences. The shape of the flower is very similar to a dandelion, although the structure of the hairs in plants is different. Over time, the inflorescences turn into curly fruits. They look like oblong capsules with a smooth (less often grooved) surface. These folded boxes contain eucalyptus seeds. The seeds are small, covered with a smooth shell, painted in a pale brown tint.

The flowering of eucalyptus is associated with the age of the tree. From 2 to 10 years old, the plant forms flowers with an ovary and fruits with seeds inside. From the appearance of the buds to the formation of the seed, it takes from 3 months to 2 years. The exact flowering season of eucalyptus is impossible to determine. It happens so chaotically that setting a time frame just doesn't make sense.

Brief historical background

In the 18th century, the botanist Lhéritier de Brutel suggests the scientific Latin name "eucalyptus". The word is derived from the Greek language and means "to hide something, to hide under sepals, hidden under the buds." The Russian language initially abandoned the Latin form and called the plant "gummy diva". Later, with the development of scientific thought, the Latin term was adopted.

Territorial distribution

Most of the species are recorded in Tasmania, Australia and New Zealand. There, eucalyptus forms whole forests and very often gives inflorescences. Several species grow and develop in the Philippines, Indonesia and New Guinea.

Eucalyptus has an amazing property - it grows quickly and drains swampy areas. There is a version that the plant is capable of disinfecting the air, but scientists have proven that this is nothing more than a myth. Already in the first year of life, the plant grows to a mark of 2 meters. By the age of 3, the threshold of 10 meters crosses, and by the age of 10 it grows to 25 meters. If the plant continues to grow and develop, and does not become a culinary spice, table or cosmetic additive, then it may well grow up to 100 meters in length. This is a truly unique example of the rapid growth of flora.

Many countries wanted to get the plant and drain the numerous swamps:

  • France;
  • Spain;
  • Portugal;
  • Israel;
  • Greece;
  • Saudi Arabia;
  • Ukraine
  • America;
  • India;
  • Cuba;
  • Abkhazia.

Beneficial features

Eucalyptus is an excellent antiseptic. It literally cleanses the body of staphylococci, streptococci and dysentery bacilli. The plant serves as a kind of prevention of the growth of Trichomonas, which are trying to penetrate the genital tract and destroy the entire genitourinary system. Eucalyptus is able to prevent the development of Mycobacterium tuberculosis and completely remove them from the body at the initial stage of infection.

The medicinal properties of eucalyptus are successfully used in both alternative and conservative medicine. If you suspect a fever caused by malaria, the patient, in addition to a whole range of additional substances, is prescribed eucalyptus. Tinctures based on the plant relieve redness, "tighten" the wound, block itching and irritation, and start the process of rapid regeneration of the skin. This is what should have been applied in childhood to the wound instead!

Eucalyptus is prescribed for:

  • burns;
  • flu;
  • catarrhal / putrefactive bronchitis;
  • respiratory pathologies;
  • pharyngitis;
  • chronic rhinitis;
  • sinusitis;
  • pathologies of the genitourinary system;
  • kidney disease.

In medicine, a decoction, tincture, alcoholic tincture and eucalyptus oil are used. Each product is distinguished by its special composition, healing properties and scope.

Decoction

The drug is taken for diseases of the gastrointestinal tract, most often the intestines. The broth relieves swelling, minimizes inflammation and disinfects not only the infected area, but also the cavity around it. Eucalyptus tea can be used for mouthwash or inhalation.

Tincture

Alcoholic and "pure" classic tinctures are intended for inhalation and ingestion. The product disinfects and prevents the development of inflammation. Alcohol tinctures are prescribed for pathologies of an inflammatory nature in the respiratory organs, oral cavity and nasopharynx.

Do not self-medicate or take tinctures without a doctor's recommendation. A self-prepared product can harm the body, cause burns and mechanical damage.

Correctly prepared and correctly prescribed tincture instantly relieves pain, stimulates expectoration and begins the fight against pathogenic microflora. The substance is used for:

  • inhalations;
  • douching;
  • rubbing;
  • ingestion;
  • wiping problem areas.

Butter

Eucalyptus oil is used for phlegmon, carbuncles and osteomyelitis. The substance acts as an analgesic pill and can minimize the symptoms of rheumatism, neuralgic pathologies, sciatica. In addition to medicinal properties, eucalyptus oil performs a purely household function - it repels mosquitoes, mosquitoes and other impartial insects.

Side effects and contraindications

Side effects only occur with uncontrolled consumption of the plant. Strict adherence to the instructions minimizes the risk of complications. In addition, a doctor or other honey should constantly monitor the treatment. employee.

Refuse the therapeutic effects of eucalyptus should be when:

  • individual intolerance to the product and the components that make up the composition;
  • the manifestation of an allergic reaction in the first few hours / days after the start of therapy;
  • hypersensitivity to the product;
  • severe kidney and liver diseases;
  • whooping cough;
  • airway spasm;
  • epilepsy;
  • chemotherapy;
  • the minimum age threshold (eucalyptus is allowed for children from 2 years old).

Pregnant and lactating women should be especially careful.

Any action, especially of a therapeutic nature, a woman should coordinate with the attending doctor. If the doctor gives permission and is ready to monitor the mother's health at each of the stages, then feel free to use eucalyptus according to the instructions and the therapeutic course. Do not self-medicate so as not to endanger your health and the life of your child.

Using an ingredient in cooking

Eucalyptus is known not only for its medicinal properties, but also for its taste. The plant is used to prepare tonic energy drinks. A mixture of eucalyptus, and very much reminiscent of the "vitamin bomb" familiar from childhood, honey, etc. Both remedies strengthen the immune system, help the body fight infections, instantly tone up and literally put a recently exhausted person on their feet. Such drinks are best prepared in the cold season to further protect the body from insidious viruses.

Eucalyptus is a traditional element of the Asian culinary tradition. The plant organically "blended" into spicy soups, sweet meat marinades and specific national dishes. Grated eucalyptus is one of the most common spices. Asians use it as often as we do black pepper.

Almost every type of eucalyptus forms a burning juice of a rich red hue. Locals call this juice "Australian cinema" and use it for soups, spicy meat and fish dishes.

Application in cosmetology

The properties of the plant have attracted all branches of medicine, including dermatology. Experts advise making a eucalyptus mask at least once a week. So women will be able to smooth out the first wrinkles, nourish the skin with vitamins / minerals, and give the face a radiant and really healthy look. Eucalyptus is suitable for dehydrated skin that lacks vitality and needs nourishment and toning.

Home care with eucalyptus

Toning cubes

Cut the plant into pieces and boil until soft. Pour the water in which the eucalyptus was boiled into ice cube trays. Every day, upon waking up, take a piece of frozen eucalyptus broth and massage along the massage lines on the face for about 5 minutes. Do not dry your face after the ice massage. Let the skin absorb the tincture on its own and saturate it with the necessary moisture. The procedure will instantly invigorate the skin, help you wake up faster and prepare for a productive day. Within a week, the pores will become narrower, the complexion will even out, the redness will subside, and the skin itself will look toned and fresh.

Mask for the face

Boil small pieces of the plant and beat them into a dense gruel. Mix with the right food for your skin type and apply to your face. 10-20 minutes will be quite enough for the skin to receive a vitamin charge, but not dry out under the influence of active ingredients.

Butter or body lotion

The recipe is similar to a face mask made from ground boiled eucalyptus. Apply a clean or fortified gruel to the skin, but do not rub in, but leave it on for 30-60 minutes. The skin will independently absorb the necessary components in a rational amount. After an hour, take a warm shower, rinse off the greasy butter and apply your usual care products. Eucalyptus will relieve irritation after depilation, visually tighten the skin, even out its color and structure.

Enrich Basic Care

In the arsenal of every woman there is at least one jar for one part of the body. In one of these jars, you can add 2-10 drops of eucalyptus oil (the amount depends on the size of the container). You can enrich everything: from foot cream to serum for sensitive skin around the eyes. The oil will prevent the appearance of the first wrinkles, stretch marks, protect the skin from ultraviolet rays or heal the traces of their effects.

A point remedy for inflammation

Apply the essential oil on top of inflammations to dry out pimples, disinfect infected skin and prevent scar tissue from forming.

Ingredient storage rules

Storage conditions directly depend on the condition of the plant. Dried leaves should be placed in sealed glass jars with a thick bottom and walls to keep out ultraviolet rays. In this state, the leaves can be stored for 3 years without losing their appearance, benefits, or taste. Eucalyptus spices should be stored in the same conditions and time frame.

Fresh plants are stored for no more than a week. During these 7 days, you need to have time to get acquainted with eucalyptus as a spice, medicine and natural beauty product. Store fresh plant in the refrigerator by placing it in a craft bag, glass or plastic container.