A shaggy creature lives in tall trees and strong vines. Most of the life of these animals passes in trees, but adult, large and heavy males, which the branches can no longer stand, live mainly on the ground.

These large animals walk on their hind legs, and locals who see them warn of the danger with the cry of Orang Hutan. Translated into Russian, this phrase means "forest man".

Based on this, the name orangutan not correct, but in Russian it is often used to name these, although in writing this will be considered a mistake, you need to speak correctly orangutan.

Orangutan habitat

In nature, these great apes inhabit exclusively the tropics. There are two subspecies of orangutans - Bornean and Sumatran, according to the names of the islands where they live.

Swampy lowlands with vast, uninterrupted forests are the environment orangutan habitat... When the distance between trees is large, they jump over it using thin and flexible vines.

They move along the branches, using mainly the front limbs, on which they often simply hang. The arm span of an adult is about 2 meters, which is much larger than the growth of the animal.

Monkey orangutan so accustomed to living in the crown of trees that she even drinks water from leaves, old hollows or from her own wool, so as not to go down to water bodies. If, nevertheless, it became necessary to walk on the ground, then the animals use all four paws.

Adults, however, walk on the ground on their hind legs, which is why they can be confused with representatives of wild tribes. Orangutans spend the night right on the branches of trees, rarely arrange a semblance of a nest.

Orangutan appearance and behavior

The appearance of humanoid gorillas is quite cute, as can be judged by multiple photos, but at the same time, adult males look intimidating. They have a massive body, a slightly elongated skull, hands reach the feet and serve as a support for the orangutan when forced to walk on the ground.

The big toes are very poorly developed. Adult males up to 150 cm.

Orangutan females are much smaller - up to 100 cm in height and weigh 35-50 kg. The lips of the monkey are plump and protrude strongly forward, the nose is flat, the ears and eyes are small, similar to human ones.

Orangutans are considered one of the smartest monkeys.

Primates are covered with tough, long, sparse reddish-brown hair. The direction of hair growth on the head and shoulders is upward, on the rest of the body - downward.

On the sides, it is slightly thicker, while the chest, lower body and palms are almost devoid of vegetation. Adult males have a fairly bushy beard and large canines. Females are smaller in stature and tend to look more friendly.

If we talk about the structural features of the orangutan's body, then the first thing that is worth mentioning is their brain, which is not similar to the brain of others, but is more comparable to a human. Thanks to their developed convolutions, these monkeys are considered the smartest mammals after humans.

This is also proved by the facts that orangutans know how to use tools to get food, adopt the habits of people if they live next to them and are even able to perceive speech, adequately reacting with facial expressions. Sometimes they even cease to be afraid of water, like a person, although by their nature they cannot swim and may even drown.

Orangutans can communicate through various sounds, which was recently proved by the Englishwoman Regina Frey. Monkeys express anger, pain and irritation by crying, smacking and puffing loudly, threatening the enemy, and males indicate their territory or attract a female with a long deafening cry.

The way of life of these animals is solitary, males know the boundaries of their territory and do not go beyond them. But strangers on their own land will not be tolerated. If two males meet, then each will try to demonstrate to each other their strength, breaking tree branches and shouting loudly.

If necessary, the male will defend his possessions with his fists, although in general they are peaceful animals. Females on the contrary calmly communicate with each other, can feed together. Sometimes they live as a couple.

Orangutan food

Orangutans feed mainly on plant foods - young tree shoots, buds, leaves and bark. Sometimes they can catch a bird, destroy a nest or catch insects, etc. They love sweet, ripe mangoes, bananas, plums, and figs.

Their metabolism is slow, similar to the metabolism of a sloth. This is 30% less than what is required for their body weight. These large animals consume few calories and can go without food for several days.

Monkeys are provided with everything necessary for food in the trees, therefore they rarely go down. Water is found in the same place, in the crowns of tropical thickets.

Reproduction and life expectancy of the orangutan

Orangutans do not have to wait for a certain season to breed, they can do it at any time of the year. The male attracts the female with loud calls.

If, however, several "macho" immediately came up with the idea of ​​mating, they will shout each in their own territory, attracting a female who will choose the most pleasant voice for her and visit the suitor's possessions.

In the photo, a female orangutan with a cub

The female's pregnancy will last 8.5 months. Most often one is born baby orangutan, rarely two. Newborn babies weigh about 1.5-2 kg. At first, the cub firmly clings to the skin on the female's chest, then, for convenience, moves onto its back.

Little monkeys feed on milk for 2-3 years, then they live next to their mother for a couple of years. And only at the age of six do they begin to live independently. Orangutans become sexually mature, approaching the age of 10-15 years. Living on average 45-50 years, female orangutan manages to raise 5-6 cubs.

In nature, these animals have practically no enemies, because they live high in trees and are inaccessible to predators. But in connection with the massive felling of tropical, they are losing their habitats.

Poaching has become an even bigger problem. Orangutans, rare in our time, are very expensive on the black market, so those who want to make money can kill a female in cold blood in order to take away her cub.

Animals are sold for the joy of people, taking advantage of the fact that they are very smart and easily trained. These animals can be taught bad habits, which can only be called mockery.

But not everyone sees in these monkeys fun or a toy, there are also caring people who are ready to help preserve the population, and treat orangutans like a human. Even a whole series has been filmed about helping babies with humanoid apes, it is called Orangutan island.

In general, these monkeys are very friendly, they are attached to people, communicate with them, make grimaces and can even perform something like an orangutan dance, a video of which you can easily find on the Internet.

Currently, illegal logging of forests, habitats of orangutans, continues. Despite the fact that national parks are being established, these monkeys are endangered. The Sumatran orangutan is already in critical status, the Kalimantan is in danger.

It seems that our "one-sixth of the historical landmass" is affected by a certain law of nature, which I rank among a number of conservation laws (matter, energy, momentum, etc.), namely, "The Law of Conservation of Corruption." In other words, corruption, allegedly rooted out in a certain sphere as a result of the next commanding campaign (like "werewolves in uniform"), in fact, simply smoothly flows into the neighboring sphere - not changing quantitatively at all, and only changing the form of existence (exactly as during transformations energy).
The meaning of introducing the Unified State Exam (which, in fact, boiled down to the entire twenty-year-old motot with the "education reform" - on which, by the way, the hell-so many annual budgets of this very education were spent) is clear even to a small child. There is a certain sphere (admission to universities) in which unmeasured (supposedly) grandmothers are spinning - direct bribes to members of admissions committees, frenzied "salaries" of tutors, indirect corruption in the form of "you to me - I to you", etc. This sphere is almost monopolistically covered by the university professorial and teaching mafia - which, of course, is not by definition; for it is said: "We must share!" After all, all this loot brazenly floats past the hands of officials of the Ministry of Education, who are very offended - what their offense I personally, by the way, quite understand. Here, in the capacity of this very "We must share!" and the Unified State Exam was invented.
Since the economic meaning of this venture, we repeat, is understandable even to a small child, the USE lobbyists have to make titanic efforts to cast a shadow over the fence. At the heart of this propaganda pyramid are, the stump is clear, the tears of provincial children - the future Lomonosovs, who are not allowed on the doorstep of Moscow State University by cruel and / or corrupt metropolitan professors-docents advancing in our people's Duma "with a bang" ...). The main feature here, they constantly tell us, is in the completely objective nature of the TEST ASSESSMENT of students' knowledge, excluding the arbitrariness of the examiner (even at the cost of some - recognized! - lowering the level of requirements for the level of the applicant) ...
This is all a preamble. And the other day I happened to communicate with my old friend Sergei Timofeevich Zhukov, a chemistry teacher at one of the special schools with a chemistry bias; the author of textbooks, the "Soros" teacher, and so on and so forth (he had just a birthday, and SMS from his former students poured in with such frequency that you can't bring a glass to your mouth). So, just before that, as a member of the college of the same high-class teachers, he participated in the verification (or rechecking?) Of this year's USE tests in chemistry for the corresponding (highest) category. And his story about this experience was interspersed with such swear words that I did not expect from the most intelligent Sergei Timofeich ...
The fact is that the test contains a bunch of questions, the correct answer to which is NOT POSSIBLE IN PRINCIPLE; sometimes he is not among the proposed options, and sometimes - the answer is simply “unknown to science”! Having tried (an experiment for) to honestly answer the EEG test, those teachers (extra-class, as already mentioned) came to the disappointing conclusion that they themselves could not score above four (according to the proposed evaluation criteria) - well, no way ... But I listened his story - about special "trap questions", questions that seem to be outside the scope of the school curriculum, questions where the correct answer was ordered to be an obvious blunder (school level), etc. - and for some reason I had a clear feeling of déjà vu ...
Oh my God! - Why, this is just one to one ours with Sergei Glagolev (from the 43rd gymnasium) 8-year-old article in the journal "Biology in School", where we showed on our fingers exactly what methods can be used with the help of those "absolutely objective" tests to put two points on the entrance exam to ANY Lomonosov; or to exhibit something else - after all, if EVERYONE answers with errors, but SOMEONE still needs to be accepted, then ... well, you understand me ...
So, the EEG - as it was repeatedly anticipated - is a mechanical transfer of all those abominations that accompanied the entrance examination epic to the level of school final exams (controlled by a different, non-university, mafia). Moreover, with the preservation of even small technological details ...
As Mikhail Verbitsky writes in such cases - "Kill them all!" Exactly. Starting with Ministers Fursenko and Filippov.

Yes, just in case - I'll post that old article of mine here. A lot of letters, and special terminology - suddenly someone is interested.

"Biology at school" No. 5 1999
HOW TO GO ON THE MINNO FIELD

Recently, tests have become widespread in universities for entrance examinations in biology. The test form has its undeniable advantages (along with equally undeniable drawbacks). Applicants of past years probably remember how many people did not get to the biology department of Moscow State University due to the fact that "the topic of the essay was not fully disclosed"; it is almost impossible to dispute the estimate lowered because of this. In the same way, any detailed written revelation, even without errors, can be appreciated: it is impossible to mention all the details contained in the textbook. The test (in theory) excludes such collisions; it differs from the good old exam in that the answer to it is unambiguous: "yes - yes, no - no" ...
The test (as, indeed, any entrance exam) should reveal two points: the applicant's knowledge of a specific biological factology and his ability to build correct logical constructions on the basis of these facts. Any teacher understands that questions "for memory" and "for consideration" are different things, and the key problem of the exam is to maintain the correct proportion between the first and the second.
In recent years, an additional objective difficulty has arisen in the conduct of exams: children study at school according to different programs, and neither they nor their parents can influence the choice of these programs. We are firmly convinced that an applicant has the right to expect that if he has studied "from and to" a certain _federal_ school course, then on the exam to the _federal_ higher educational institution he will not face questions that were not covered in the aforementioned course. Thus, the task of the test writer is also to somehow "bring to a common denominator" the aforementioned courses (for example, excluding cases when the numbers and information given in different textbooks contradict each other). This, of course, is troublesome, but not so difficult: all textbooks passed through the same expert council and, on the whole, correctly reflect the current scientific views.
In addition (even somehow inconvenient to mention this), the test should not contain actual or logical errors. In other words: the authors of the test should know biology - within the framework of the school course - at least as well as those whom they are examining.
Let's try to analyze how things stand from this point of view with the tests that are offered to applicants for entrance exams. The reason for this analysis was, first of all, the publications of A.A. Kamensky and N.A. Sokolova (journal "Biology in school", 1997, No. 1, p. 62-65; 1998, No. 1, p. 54-60), and also published by these authors (in co-authorship with S.A. Titov) a collection of tests "1000 questions and answers. Biology: a textbook for applicants to universities" (Moscow: Book House "University", 1998). (We will designate the questions from the collection by the initial letter of the section to which they relate: B - botany. 3 - zoology. A - anatomy and physiology. O - general biology. The answer, which the authors of the collection cite as correct, is highlighted in bold. ( here _aaa_ - KE) School textbooks are cited by the name of the first author or editor.)
The thousand examination test questions offered to the readers of the collection can be classified as follows.
Group 1. Questions that objectively assess the preparation of the applicant (they make up about 80%).
1.1. Simple questions to remember. Example:
A-190. The cervical spine of a person is formed by: a) 5 vertebrae. 6) 6 vertebrae, c) _7 vertebrae_, d) 8 vertebrae. A thing, of course, necessary, especially for those who usually "leave" on this kind of answers: memorized - and order.
1.2. Questions testing both "memory" and "consideration". Example:
3-203. The heart in tadpoles is: a) single-chambered, b) _double-chambered, c) three-chambered. d) is absent. This type of questions seems, in our opinion, ideal: here the applicant is required not only to know how many chambers there are in the heart of amphibians (three), but also to figure it out. that in a tadpole, unlike an adult frog, respiration is gill and, accordingly. there is a single circle of blood circulation and a two-chambered heart. The only annoying thing is that there are not many such questions (compared to type 1.1).
Group 1 exhausts the questions aimed at identifying the real level of knowledge of the applicant. Then the tests begin, the only purpose of which (as it seems to us) is to "cut" the applicant and reduce his final grade. The first "filter" through which an applicant will have to pass is "relatively honest" (according to Ostap Bender) "fill-in" questions.
Group 2. Questions "for filling".
2.1. Questions about the senseless memorization of numbers (there are also reference books). Examples:
3-243. The number of marsupial species is approximately: a) 50, b) 100, c) 150, d) _250_. It would be interesting to walk through the corridors of the biology department of Moscow State University and, after conducting a survey of candidates of sciences, find out which of them will give the correct answer to such a question (and there are at least 50 of them in the collection).
0-164. Photosynthetic productivity, modified in tons of organic matter per year. is approximately: a) 10 2. 6) 10 3. c) 10 5. d) _10 7_. According to data from Whittaker, which are cited in most environmental textbooks, the annual net primary production of the globe is 170 billion tons (ie more than 100,000,000,000 tons). This differs from the figures from the school textbook by three orders of magnitude. Not, but about the fact that schoolchildren poorly remember numbers with degrees (which has been repeatedly shown by psychologists), we are not talking.
There is one more problem here: the biosphere productivity figure is given only in Polyansky's textbook; in Belyaev's textbook (now used in most schools, for example, in Moscow) it is not. This brings us very close to the next subgroup of questions.
2.2. Questions outside the school curriculum. Example:
0-42. Gibbons and orangutans descended from: a) parapithecus, b) _propliopithecus_, c) driopithecus, d) pithecanthropus. Orangutan is the wrong name for an orangutan (see school textbooks), but this is half the trouble ... It is completely incomprehensible where the "proplyogpithecs" themselves came from, and the corresponding answer to the question: it was not possible to find this name in school textbooks at all. It was not without difficulty that we "followed the trail" of the propliopithecus in the book of the paleoanthropologist R. FOWLEY "Another Unique View" (Moscow: Mir, 1990). From this book, however. it follows that the propliopithecines became extinct in the Oligocene, and the immediate common ancestors of the orangutan and gibbon, apparently, were other forms that lived in the Miocene. Thus, the issue is clearly controversial and - in any case - is not covered at all in the textbooks.
Such frank departures from the school curriculum in the collection of units. Another thing is questions that require knowledge of terms or concepts, as well as the characteristics of specific organisms, which are considered only in one of the parallel textbooks and are not directly required by the program for applicants; such questions are innumerable. Example:
B-177. The male reproductive organs of ferns are called: a) gametes, 6) outgrowths, c) archegonia, d) _anteridia_. We are convinced that an applicant who studied botany according to Korchagina's textbook (and there are probably more than 50% of them now) does not have to know the terms "archegonium" and "antheridium" (they are only in Serebryakova's textbook); to know the structure and functions of the "male and female organs of the fern" - yes, there are no questions.
It turns out that students are required to know what type of germination in buckwheat and onions is underground or aboveground (B-42); what form of chromatophores in spirogyra (B-153) and what form in cladophores (B-155); with what frequency does bamboo bloom (B-218) and is there sexual dimorphism in the size of the toothless (3-99); whether mushrooms cause blackleg and potato cancer (B-243) and whether empusa belongs to lichens (B-245); how much ATP is produced in the Krebs cycle (0-155); what is glycocalyx (0-153), hyaloplasm (0-149) and intussusception (0-185) ... Fortunately (for applicants), the test writers have not yet got their hands on the recently published - and very good, multi-level - textbook zoology Dolnik and Kozlov. Otherwise, you can open it, for example, in fig. 197 and ask the following questions: "What is the level of DNA difference (in percent) between ostriches and tinamiformes? How many million years ago did the common ancestors of anseriformes and woodpeckers live? Who is the closest relative of the birders - cuckoo, anseriformes, or trogoniformes?" Are you dissatisfied with something? .. In vain: this information is contained in one of the federal textbooks for high school - so everything is legal!
In general, the questions of group 2 are what the well-known quote is applicable to: "It is true in form, but in essence it is a mockery" ... However, let our student be an ideal applicant: he has learned all textbooks recommended by the Ministry of Education before the exams ( at least four - in botany, three - in zoology, etc.). At the same time, he has a photographic memory, and you cannot catch him in any terms and numbers. Do you think this guarantees him a "five" on the exam? No matter how it is! In this case, the compilers of the test have the following "filter" in store.

Group 3. Trap questions
3.1. Questions for the "helluva lot" (directed against those who really know the subject beyond the school curriculum: the really correct answer is declared erroneous due to discrepancies with the existing curriculum). Example:
0-40. The ancestors of modern birds appeared in: a) equine of the Paleozoic. 6) Triassic, c) Yure, d) the beginning of the Cenozoic. The compilers of the test, it must be understood, are considered the ancestor of the "modern birds" of the Jurassic Archeopteryx. However, the student can - to his misfortune! - to be aware of modern views on the evolution of birds (they are set forth, for example, in the federal textbook of Dolnik and Kozlov). Knowing about that. that Archeopteryx is in fact the ancestor of not "real", but tailed (enanciornis) birds, and about the Triassic protoavis, he. will undoubtedly choose option b - and will receive a net minus for this question ...
3.2. Questions that even scientists do not know the exact answer to. Example:
0-48. The first to master articulate speech were: a) Neanderthals, b) Cro-Magnons, c) Sinanthropists, d) Heidelberg man. To begin with, the textbooks give the wrong answer to this question, which is considered correct in the test. So. in Ruvinsky's textbook, a hypothesis is expressed that the archantropians have already mastered speech; in Belyaev we read: "The ancient people (Neanderthals) had a further development of speech." Thus, the correct answer can be both a and c. The main thing, however, is different. The moment of the appearance of articulate speech is one of the most controversial issues in paleoanthropology, since all the arguments here, as you might guess, are purely indirect (although at present, the existence of articulate speech among Neanderthals who performed complex funeral rites is not in doubt). And a natural bewilderment arises: if scientists have not yet been able to agree on this issue among themselves, is it worth involving students in these "showdowns"?
3.3. Questions with an ambiguous answer or wording. Examples:
3-221. Ancient giant lizards reigned: a) in the Permian period. 6) in the Carboniferous period, c) in the Cretaceous period, d) _not one of the answers is correct_. Everything here raises questions. Who are the "lizards"? From what size can they be called "giant"? What do you mean "reigned"? But even if we consider that all this is obvious, the question arises - who "reigned" in the Cretaceous period, if not the dinosaurs, the largest number of species of which is known precisely from the Cretaceous (including the character of the movie "Jurassic Park" - tyrannosaurus)? And weren't the giant "animal-toothed lizards" (herbivores - the size of a bull, carnivores - the size of a tiger) that "reigned" in Perm?
Z-233. The mass of the pectoralis major muscles in birds: a) is equal to the mass of all other muscles in the bird's body, b) less than the mass of the remaining muscles, c) more than the mass of the remaining muscles, d) none of the answers is correct. And here's what the textbooks say. Kozlov: "Their mass is the same as that of the rest of the muscles." Nikishov, Sharova: "The pectoral muscles of good flyers make up 1/5 of their body weight" (less than 1/2 of the muscle mass). Naumov, Kartashov ("Zoology of the vertebrates", v.2): "Both pectoralis major muscles make up from 10 to 25% of the total weight of the bird." Here is the answer: this value varies by 2.5 times. If the compilers did not write "bird", but "dove" (by the example of which the anatomy of birds is studied), everything would be correct. But in the proposed formulation, the applicant must take into account both the flightless ostrich (for him the answer is "c"), and the hummingbird capable of "hovering" like a helicopter (the answer is "b"). In general, any of the four answers can be considered correct! And at the same time, the examiner, if desired, can evaluate any of the answer options as erroneous.
As a matter of fact, the applicant has the right to appeal with all the questions of group 3, since the "official" answer is incorrect or, at least, incomplete. However, these are still flowers.

Group 4. Questions, in the answers to which the authors themselves make direct mistakes of the "school level". Examples:
0-50. The Homo sapiens species include: a) Neanderthals, b) Cro-Magnons, c) Sinanthropists, d) Heidelberg man. Outright mistake. The species Homo sapiens includes two subspecies: Neanderthal (H. sapiens neandertalensis) and Cro-Magnon (H. sapiens sapiens) - this is written in any school textbook.
B-141. With the help of animals, fruits are distributed: a) _ryan_, b) oak, c) ash, d) sedges. Perhaps the authors of the test have forgotten that the seeds of some sedge species are spread by ants, and the fruits of other species are spread on the legs and stomachs of ducks (see "Plant Life"). But the fact that jays hide acorns and, losing their pantries, participate in the resettlement of the oak, schoolchildren interested in biology must have read. So, instead of one correct answer - three ...
B-96. A palm-complex leaf is found in: a) beans, b) rose hips, c) maple, d) _chestnut_. In chestnut (Castanea sativa), the leaf is not finger-complex, but simple. The authors of the test clearly confused it with the horse chestnut (Aesculus hyppocastanus), a plant from a completely different family, which has about the same relationship to chestnuts (Castanoideae) as a guinea pig to pigs.
The case of the horse chestnut is by no means an isolated one. So, in question B-114, the "violet" clearly means Saintpaulia from the Gesneriaceae family (colloquially - "African violet"), and in question 3-188 there appears "a giant whale shark" (there is a giant shark Cetorhinus maximus and a whale shark Rhincodon typus , they belong to different families).
3-186. The heart of all fish has: a) one chamber, b) two chambers, c) three chambers, d) none of the answers are correct. This is what zoology textbooks write. Nikishov, Sharova: "The heart of the fish ... consists of two chambers ..." Kozlov: "The heart of the fish is two-chambered." IAShilov's university textbook: "The heart of aquatic vertebrates [cyclostomes and fish] is two-chambered." Apparently, the authors of the test set another trap for the applicants, but fell into it themselves. Indeed, in the heart of many fish there is also a venous sinus and an arterial cone, and in lungs, an incomplete septum appears in the atrium, however, as far as we know, no one has ever counted all these structures as separate chambers.

So, let's summarize. We are not at all inclined to cross out all the great work that the authors of the tests did: most of the questions they put up do not cause any objections. However, the total "marriage rate" (and we include not only direct mistakes and overexposure, but also questions like 2.2) for such a responsible matter as the entrance exam is unacceptably high. It turns out that about 15% of the questions in the collection being analyzed are unsuitable for testing the knowledge of schoolchildren for various reasons (including an incorrect or unclear answer, as well as the presence of two or more correct answers instead of one).
But, perhaps, such a high percentage of rejects is associated with a large volume of the collection, but on real exams everything is different? Unfortunately, the authors' publications devoted to the "analysis of mistakes" of applicants from Moscow State University, the Institute of Psychology of the Russian State University for the Humanities and the Faculty of Fundamental Medicine convince the opposite. Here are just a few examples (the numbers show the question numbers in the respective publication).
MSU-9. Among the listed plants, the cruciferous family includes: a) carrot, b) dill, c) plantain, d) lilac. Carrots belong to the umbrella, and crucifers are simply not on this list. For such a question, it’s just right to start the heading "Examiners are joking" - only here the applicants, one must think, are not at all funny ...
MSU-6. Among the listed bacteria, chemosynthetics are: a) bacteria of putrefaction, b) _azotobacter_, c) purple bacteria; d) all answers are correct. Nitrogen-fixing bacteria are classified as chemosynthetics in Polyansky's textbook. However, the definition of chemosynthesis given in the same textbook (and generally accepted) clearly indicates that a mistake has been made: azotobacter receives energy for nitrogen fixation not due to the oxidation of inorganic substrates and therefore does not apply to chemosynthetics. Note that the very concept of "chemosynthesis" is not found either in Belyaev's parallel textbook, or in the program for applicants to the biology department of Moscow State University.
MGU-36. For the first time, oxygen began to emit into the Earth's atmosphere: a) bacteria, b) fungi, c) algae, d) viruses. The first oxygen generators were actually cyanobacteria (Cyanophyta). For them, however, they sometimes use the common name "blue-green algae", but these prokaryotic organisms have about the same relationship to real algae (Algae) as water lilies or aquatic species of fungi.
Total - again, about 15% of the questions from those that "caused difficulties for the applicants", in reality, were simply incorrectly compiled or incorrectly assessed. Note that at the Russian State Humanitarian University the mark "excellent" was given only with 58 correct answers out of 60; and if the same requirements were made to the test writers themselves, they would receive a grade between 4 and 3.
School teachers cannot but worry about this situation. We are all concerned about the fate of our graduates, especially the most gifted children who have chosen the path to science. Unfortunately, the published collection documents the darkest stories of biology entrance exams. One gets the impression that it is impossible to honestly overcome the "echeloned defense" erected by the examination commissions (and get 58 out of 60): you must at least have a "minefield map" and their possible content). It is unlikely that this contributes to the recruitment of the most capable and biologically literate schoolchildren in universities ...
In principle, it is not difficult to rectify the situation. Take at least the same thousand tests in question, and "separate the wheat from the chaff." To do this, it is enough to distribute them to several specialists in the relevant sections of biology (to correct mistakes) and several reputable biology teachers in the pedagogical world (in order to ensure that the questions correspond to the school curriculum). The question is whether our colleagues from higher education are interested in putting things in order ... I still want to believe that we have common goals.
P.S. When the review was already written, a reprint of the collection was published (AA Kamenskiy. NA Sokolova, SA Titov. 1000 questions and answers. Biology: Textbook for applicants to universities. M .: Book house "University" . 1999. 2nd ed. Rev.). We decided that our labor was wasted (and thank God!); Presumably, the authors received a lot of reviews, similar to ours, and corrected mistakes ... However, it turned out that not a single comma was replaced in the text of this "corrected" edition! Everything is as it was - and parapithecus with propliopithecus, and chestnut with palmate-complex leaves, and even "orangutan" in two "g" ...
S.M. GLAGOLEV, candidate of biological sciences,
K.Yu. ES'KOV, Candidate of Biological Sciences, Moscow

Orangutans - Pongo

Class Mammals (Mammalia)
Subclass of Trechnotheria
Infraclass Greater Beasts (Eutheria)
Archonta Superorder
Euarchonta Grand Squad
Order of Primates (Primates)
Suborder Euprimates
Infraorder Dry-nosed monkeys (Haplorhini)
Parvorod Anthropoidea
Narrow-nosed monkeys (Catarrhini)
Superfamily Hominoids (Hominoidea)
Family Hominidae
Subfamily Ponginae
Tribe Pongini
Genus Orangutans ( Pongo)

Orangutans, or orangs ( Pongo Lacépède, 1799) is a genus of large arboreal hominids (Hominidae) from Southeast Asia, where they have been known since the Pleistocene. 3 fossils and 2 modern species are described, which are now under threat of extinction.

The appearance of a young male Pongo abelii.

Etymology and history of study

The name "orang-utan" is of Malay origin and means "forest man" (it is noteworthy that local farmers - Bataks - call this not only monkeys, but also primitive tribes of forest gatherers, for example, Kubu). The sometimes used name "orangutan" is erroneous, since in translation it means "person-debtor". The locals have hunted orangutans since ancient times, sometimes tamed them and kept them as pets. The remarkable ingenuity of these monkeys has long been noticed by the population of the region. So, according to one of the beliefs, orangutans know how to speak well, but do not do it in public, so that they would not force them to work.

Apparently, in scientific publications the word "orangutan" was first used in 1641 by the Dutchman Nicholas Tulp; however, he designated them chimpanzees from Angola. Considering that the Europeans first came to Kalimantan a hundred years earlier, Malay legends about the "forest people" probably had already spread widely by this time. Another Dutchman, Jacob Bontius, who was a doctor in Java, soon used the word "orangutan" correctly when describing an animal from the islands of Sumatra and Kalimantan (his description was included in Buffon's "Natural History"). Still, until the end of the 18th century, orangutans often continued to call all indiscriminately anthropoids.


Old image of an orangutan (1876).

Modern generic name Pongo dates back to the English sailor Andrew Battell, who in the 16th century designated him a humanoid African primate (most likely a gorilla). Relative order in the taxonomy of anthropoids was established only in the 19th century. Initially, a single species was identified - Pongo pygmaeus, however, at the beginning of the XXI century, on the basis of morphological, behavioral and genetic differences, the independence of the second species was confirmed - Pongo abelii... Beginning in the 19th century, hundreds of scientific papers have appeared on orangutans with all sorts of anatomical and physiological details - and often with speculative constructions based on these characteristics, since none of those authors seems to have observed these primates in the wild.

The study of orangutans in nature was first undertaken by Barbara Harisson in the middle of the twentieth century. Another outstanding researcher who has continued her work in this field almost today is Birute Galdikas. In addition, along with other great apes, orangutans have undergone many laboratory studies in order to study their intelligence and communication skills. Unlike quite rare in nature, in captivity, they have recorded numerous cases of using tools. The monkeys have also demonstrated the ability to solve difficult tasks, such as opening a buckled box. As part of the study of communication, orangutans were taught sign language and graphic symbols. In early 2011, a group of researchers announced the genome sequencing of these primates.

Old male Pongo pygmaeus.

Morphology

Orangutans are large monkeys with pronounced sexual dimorphism, their males are much larger than females. The average body length of adult males is 95-100 cm, of females - 75-80 cm; the height in a straightened position is 120-140 (up to 158) cm in males and 100-120 (up to 127) cm in females. The body weight of adult males is 50-90 kg, but in captivity they become very fat and can reach 190, and according to some sources - even 250 kg. The huge size and peculiar appearance serve the male to intimidate competitors if they attempt to encroach on his territory and powers. Females are about half as light and weigh about 30-50 kg. Orangutans from Kalimantan and Sumatra are approximately equal in size and mass, but the highest rates were recorded among the Sumatran inhabitants.

Portraits of adult male and female Pongo pygmaeus.

The constitution of orangutans is massive and rather awkward, they have strongly developed muscles, usually they have a large round belly. These animals are perfectly adapted to the arboreal lifestyle. Their powerful forelimbs are greatly elongated, with a straightened body position they reach almost to the ankles, and their range in large individuals can reach 2.25 m. The ulna and radius are longer than the humerus. The hands are elongated and wide, the first finger is poorly developed and almost incapable of manipulation, the rest of the fingers are long and strong. When moving through the trees, four fingers of the hand grasp the branch like a powerful hook. The hind legs are 30% shorter than the front legs.

Due to the great mobility of the wrist and shoulder joints, when climbing the branches, the orangutan can turn out at a variety of angles. The hip joint is also almost universal. The monkey is able to stretch the leg down, backward, forward, to the side at right angles and almost vertically upward. Due to life in trees, the first toe is rudimentary and often devoid of a nail, but can rotate and oppose the rest of the toes, the other toes are well developed. The foot is kept in a bent state and is capable of grasping, not inferior in tenacity to the hand.

Male skeletons Pongo abelii.

The hair is rather sparse, but shaggy and long. In adults, it is so significant on the shoulders and upper arms that it hangs over 40 cm in shags. The coat is hard, reddish-red, with age it darkens a little. Coat color ranges from bright orange in young animals to brown or dark chocolate in some adults.

The lungs are not subdivided into lobes. In front of the powerful neck there is an unpaired laryngeal sac with many branches, which serves to amplify the voice. In males, the capacity of the sac reaches several liters, in females it is less developed. Ischial calluses are usually absent, they are found only occasionally and are small in size. Orangutans have blood groups A, B and AB (no group O) and other components of human blood. They have 48 chromosomes in their diploid set.

Left hand and foot Pongo abelii.

The head is large and round. The front part is wide, slightly protruding forward and has a spherical shape. The skull is quite tall. In males, the sagittal and lambdoidal ridges are highly developed. The forehead, unlike most anthropoids, is high and convex; the superciliary arches are moderately developed. The eyes are small, close-set. The profile of the face is concave; the jaws protrude strongly forward. The brain is relatively large, reaching 300-500 sq. cm in volume and is similar to a human.

The face is naked, wide; ears are small; the lips are able to stretch strongly, especially the lower one. The complexion is gray, brownish or almost black, slightly pinkish in young animals. In adult males, elastic, slightly hairy growths in the form of semicircular ridges up to 10 cm wide and up to 20 cm long, formed by adipose and connective tissue, develop on the sides of the head. From above, the rollers converge on the forehead, and from below they merge with the resonator bag. From the side it seems as if the monkey's face is edged with thick folded skin. Rollers continue to grow after reaching puberty and reach their largest size in older animals. With age, males also develop a yellowish beard and mustache, growing no longer in the middle above the high upper lip, but on its sides. Adult females also have a beard, but it is not so strongly developed.

Scull Pongo pygmaeus, front and bottom view.

The jaw apparatus is rather massive, the teeth are large. Like other monkeys of the Old World, the dental formula is I2 / 2 C1 / 1 Pm2 / 2 M3 / 3 = 32. The enlarged incisors have a spade-like shape, especially their large first pair. The canines of males are much larger than those of females. The molars are large and flat, with a ribbed surface and hard enamel. The chewing surface of the cheek teeth is covered with a complex pattern of small grooves and wrinkles. Orangutans' jaws and teeth handle both soft and hard foods with equal success and are excellent adaptations for plucking fruits, termitic twigs, stripping bark from trees, grinding hard seeds, and cracking shells and nuts.

Median section of the orangutan's head.

Habitat

Previously, orangutans lived throughout Southeast Asia, but today they survived only in some areas of Sumatra and Kalimantan. They usually inhabit primary and secondary rainforests in swamps, plains and hills at an altitude of 200-400 m above sea level, but sometimes they rise into the mountains to an altitude of 1500 m.

The amount of precipitation in Sumatra averages about 3000 mm per year, the wet seasons last from March to June and from September to December. The average annual temperature is 29.2 ° C, but in different months it ranges from 17 ° C to 34.2 ° C. Humidity reaches about 100% throughout the year. Kalimantan is even hotter and more humid. On average, 4300 mm of precipitation falls annually. The wet season lasts from December to May, September is also rainy, and June to August is rather dry. The air temperature ranges from 18 ° C to 37.5 ° C.


Distribution area of ​​orangutans.

Orangutans are rather phlegmatic animals that grow slowly, reproduce little and live long. Their life, quite calm and lazy, is a consequence of living in an environment where mortality is low, and periods of lack of food are not a big problem. In Sumatra, a monkey can fall prey to a tiger ( Panthera tigris sumatrae). The much smaller clouded leopard ( Neofelis nebulosa), inhabiting Kalimantan and Sumatra, is a danger mainly for females and calves. Sometimes these monkeys are attacked by crocodiles and feral dogs.

Movement

Orangutans are strictly arboreal, found at all levels of tall trees. They are the largest among modern arboreal mammals. These monkeys easily swing on the branches (brachiate), climb and walk on them, and in most cases they do it carefully and without haste. They never jump like gibbons because they are too heavy for that. Nevertheless, in the upper part of the forest, orangutans are able to move at a speed no less than that with which a person runs on the ground. Usually, when moving, the body is in an upright position, the lower limbs grope for branches, but they step on them not with the whole sole, but only with bent fingers, while the upper limbs alternately intercept the branches, having previously checked them for strength.

Young individual Pongo abelii on the tree.

Sometimes monkeys swing the tree they sit on from side to side until they can grab a nearby tree with at least two limbs. This is due to their tenacity and ability to move freely in different directions. Both the hands and feet of the orangutans are perfectly adapted to grasping. Monkeys can climb high into tree crowns. Incredible strength and agility allows animals to reach food that would otherwise be unavailable.

As a rule, monkeys hang, sprawled on trees, holding onto branches with those limbs that are more convenient for them, and with their free they get their food, mainly fruits. If large males, due to their heavy weight, cannot climb the thin branches on which fruits grow, they simply sit in the middle of the crown and begin to break or bend the branches towards themselves. In this way, they manage to quickly clear the tree of fruits, crippling and breaking many branches.

Pongo pygmaeus moves on the ground.

Females and calves descend from trees extremely rarely, but overweight males can sometimes be seen on the ground. As a rule, monkeys go down only to get to a new tree. Here they slowly move on all fours, resting on the dorsal surfaces of the middle phalanges of the toes of the forelimbs and on the outer edges of the feet; can also step on hands clenched into fists. Sometimes, with faster movement, the hind legs are thrown forward between the forelegs. In Kalimantan, monkeys descending from the trees can be seen more often. This is due to the fact that tigers are not found here, unlike Sumatra. Orangutans do not know how to swim, but sometimes they were noticed in the water.

Female Pongo pygmaeus with a cub wade into a pond.

Nutrition

Orangutans can eat a lot and sometimes spend the whole day sitting in a tree with fruits and devouring them. It has been established that the diet of these primates includes up to 400 different plant species. From 60 to 90% of all eaten are fruit fruits - both ripe and unripe, especially with sweet and fatty pulp (durian, jackfruit, figs, rambutan, lychee, mangosteen, mango, plum, etc.). Most often, monkeys are attracted by durian trees up to 30 m high, with sparse foliage. The durian fruit, which looks like spiky soccer balls, is a favorite dish of the orangutans. Having plucked the fruit, they open it with their teeth and hands. Then, sticking their fingers inside, they extract the white pulp with nuts and eat it.

In some areas, fig tree fruits are the basis of the diet, as they are high yielding, they are easy to harvest, and they are well digested. At the same time, orangutans even consume fruits containing strychnine without any difficulty. Strychnos ignatii, the only visible effect of which they have is perhaps increased salivation. By spreading the seeds of eaten fruits, these primates contribute to the dispersal of many plants. Cases of use of the plant by orangutans are noted Commelina, which has an anti-inflammatory effect.

When there are not enough fruits, orangutans feed on seeds or rip off the bark from trees and vines in order to get to its inner layer - bast, it is in such times of famine that good and strong teeth serve them faithfully. In addition, monkeys regularly eat young leaves, shoots and flowers, sometimes feasting on chicks, bird eggs, lizards, honey, insects, snails and other small invertebrates; sometimes they eat soil rich in minerals. In addition to being rich in micro and macro elements, the consumed clay soil can be beneficial in that it absorbs the toxins contained in plant foods, it also helps with intestinal disorders such as diarrhea.

The male orangutan eats the leaves.

There is also information about eating meat by orangutans. So, in the National Park of Indonesia Gunung Leser, a pair of adult animals, a male and a female, fed on the carcass of a white-armed gibbon for 3 hours, eating it without a trace. Usually, primates are content with moisture obtained from juicy fruits, but if it is not enough, they drink water that accumulates in the recesses of the trunks, lick raindrops from wool and trees, suck on moss, orchids or their hand, previously dipped in water.

In Indonesia, with a pronounced change of seasons, summer is the happiest time for orangutans. Thanks to the abundance of fruits, monkeys eat a lot and quickly gain weight, storing fat for the future, for the rainy season, when bark and wood will be almost their only means of subsistence. At this unfavorable time, they are forced to do without food for many days. Obviously, it is the orangutans' predisposition to overeating in the presence of a large amount of available food that is the main reason for their obesity in captivity.

Metabolism

Recently, it was found that the metabolism of orangutans is about 30% lower than calculated based on their body weight. It is estimated that the average orangutan consumes between 1,100 and 2,000 calories throughout the day. For comparison: a person who is not burdened with even light physical work, as a rule, burns 500-1000 more calories per day. Probably, such a low level of metabolism was developed in orangutans due to their unhurried lifestyle and seasonal minimum of food resources.

Recreation

Orangutans are active during the day. Like other large anthropoids, they build nests at night. Having chosen a safe place, usually in a fork in the branches, the primates deftly break off large branches around themselves and lay them in different directions until they form a sufficiently reliable platform. The movements of animals are measured and unhurried, sometimes they take some branch again and rearrange it in a different way. Then the resulting frame is braided with thin rods and laid out on top with leaves, and they are often placed in an "artistic" order. The resulting litter is compacted. At night, especially in rainy seasons, orangutans often cover themselves with branches or some large leaves; sometimes another layer of the platform is constructed for a secure waterproof roof. Nests are built in the middle of the tree at a height of 10-20 m from the ground, where it is less windy.

The female sleeps in the same nest with the cub, clutching it to her chest. Other members of the group tend to build separate nests for themselves, sometimes helping each other. They sleep in the same nests during the day; sometimes new nests are arranged for daytime rest. Usually the nest is used one night or several nights in a row if the monkeys stay in the same place for a long time. Sometimes a new nest is built next to an old one. Orangutans sleep supine or on their side with legs pressed to their stomachs, holding onto branches with one or both hands. It is known that they spend about 60% of their time sleeping. Waking up with the first rays of the sun, they slowly stretch and scratch themselves, rub their eyes with their fists and look around. Then they leave the nest and go to breakfast. The hottest midday hours are also enjoyed by orangutans napping in their nests. Thus, the main activity of monkeys is in the morning and evening.

Communication

Compared to other great apes, the vocal abilities of orangutans are not very diverse. Sometimes they sigh heavily, grunt and squeak. With loud smacking and panting, monkeys express a threat, whimpering and crying - anger, irritation or pain. A young animal may whine when asking its mother for something.

A male who wants to designate his territory or attract the attention of females makes a kind of loud cry. His vocal exercises begin with a deep, vibrating squelch that gradually turns into a deafening groan. At the same time, the monkey's throat sac swells like a balloon, and large air cavities-resonators located under the skin of the chest amplify sounds so much that they can be heard from a kilometer away. The performance ends with a bass grunt. As one researcher noted, the orangutan's "song" is reminiscent of the sounds of a car when shifting gears.

Communication of orangutans.

When we analyzed the patterns of how orangutan females respond to a call addressed to them, it turned out that what was previously considered just a “mating cry”, in fact, serves not just to attract attention, but contains very specific information about the personality and status of a potential mating partner. His chances are further increased if a third male wedges into the conversation, over which superiority can be demonstrated. Also, the researchers were able to identify two main communication patterns among orang males with each other. The first, "preventive" one, is addressed by the adult male to young or weak potential rivals so that they stay away. The second option is the almost instantaneous response of the dominant to the heard call of another male.

It has also been noted that when orangutans make sounds warning of an impending danger, they can significantly change their voice with the help of leaves attached to their mouths. The sounds they make in this way not only signal their relatives about the threat, but also show a potential attacker (leopard, tiger, snake) that they have found him. The usual (lip) calls of orangutans are quite high - about 3500 hertz, the hands lower the frequency to 1800, and the leaves - to 900 hertz. Meanwhile, the lower the sound, the more likely the animal is large, which means that it is better not to mess with it and look for a smaller victim. Perhaps, using the leaves, orangutans are trying to trick the predator, because they emit cries of alarm only when they are very frightened.

It is noticed that in those populations where such a deception exists, almost all orangutans of various ages use it. This may mean that this method is quite effective against attackers. However, since the reaction of predators to the "altered" calls has not yet been established, this cannot be said for sure. Still, it is curious that animals, not accustomed to the presence of a person nearby, screamed much more often than those who were already familiar with Homo sapiens. These facts indicate that orangutans understand what other animals know and what they don’t know (i.e., how predators perceive one or another of their calls). One way or another, these monkeys are the only creatures besides humans capable of manipulating sound with the help of improvised means.

In addition, in the course of evolution, orangutans have developed a rich sign vocabulary that allows them to communicate with each other quite intensively. Researchers identified 64 different gestures in these primates (28 individuals from three European zoos were studied), and 40 of them were repeated often enough to accurately recognize their meaning, which is equally understood by almost all experimental animals. Based on the results obtained, a dictionary was compiled. It contains such gestures as a somersault, a turn back, a bite of air, twitching by the hair, placing objects on the head (the latter means "I want to play" - this is almost the most common saying in the orangutan language). And to show that you need to follow her, the monkey hugs the communication partner and easily pulls in the right direction.

It is noteworthy that some of these gestures are similar to those of people. For example, to give a stop signal, the orangutan lightly presses the hand of the “interlocutor”, who, in the opinion of the first monkey, is doing something wrong. Human children who cannot speak often do the same. Monkeys can repeat a gesture quite stubbornly if their counterpart does not respond to it with a certain action, that is, they clearly speak body language, putting a very specific meaning in their intentional message. In combination with the high frequency of use, all this may indicate the initial stage of the formation of a kind of language. Mimic communication of orangutans has not yet been studied enough.

Pongo abelii in the process of communicating with a relative.

Intelligence

Among primates living in captivity, orangutans score the most in intelligence experiments. They easily learn to use a rudimentary language system centered on six food objects and in 2 years are able to assimilate and use about 40 token signs. Also, these monkeys demonstrate the ability to independently invent and change gestures, depending on how well others understand them.

In a number of experiments, orangutans have shown that they can easily accept the value of money and even buy food for each other, but they do this only if the subsequent carve-up is equal. “If you don’t give me enough, then I will not share with you, but if you have at least some benefit, then I’m ready to buy your cooperation,” - this is how the researchers describe the thinking of these primates weighing costs and benefits from their interactions with relatives.

The great intelligence of orangutans is especially striking when observing them in captivity. So, an old male named Marius in the Munich Zoo introduced a special procedure for maintaining cleanliness in the cage. He began to use an old soldier's helmet as a chamber pot. Sitting on it and doing everything necessary, he carefully carried the helmet to the grate and poured the contents through the bars into the drain. This orangutan was generally distinguished by its special cleanliness and swept all the litter out of the cage. The attendants hardly had to clean up after him.

Wild orangutans use their intelligence to create complex foraging schemes. Sometimes they devise gadgets that enable them to get to food supplies that are inaccessible to other inhabitants of the jungle. In some places in Sumatra, monkeys purposefully tweak the branches to extract seeds from the large fruits of the nessia, since these seeds are protected by a mass of thorny hairs. The leaves are used as wipes to dry themselves, or as gloves to protect against the thorns on the durian fruit. It is known that trapping leaves-jugs of insectivorous plants served as a cup for monkeys.

Orangutans also use special tools to extract honey from bee nests or to check tree hollows for ants or termites, scratch themselves with sticks, brush off pesky insects with branches, and make an umbrella out of the leaves to protect them from rain or sun. In captivity, the monkeys used sticks to push the bait out of the tube, chewed the branches, turning them into a sponge, which they used to draw water from a vessel. However, although orangutans can manipulate objects well, they use this ability little, inferior in this respect to chimpanzees.

Orangutans are excellent imitators, they are able to quickly adopt and copy the behavior that has been observed in other relatives or even humans. Observations of these primates have shown that they can mimic up to 90% of the movements seen. Being near people, monkeys easily adopt human habits. In rehab centers, some orangutans copied people by washing things in soap and water. They also reproduce the methods of using the tools of labor. One young female even learned how to saw wood and hammer nails. The natives of Kalimantan - dusuns - still use orangutans as pets, starting to educate them from early childhood and teaching them to perform duties in the house: swing a cradle with a child, carry water, uproot stumps, etc.

In one of the cases in Kalimantan, monkeys saw local fishermen with fishing rods, and then tried to fish themselves with the help of tools thrown by people. One male guessed to use the "pole" left by the man as a spear. He climbed onto branches hanging above the water and tried to pierce the fish floating below with a stick. Alas, he did not manage to get it in this way. But with the help of the same tool, this orangutan successfully fished out floating fruits that fell into the river. Another orangutan used the found sticks to pull ashore a fish entangled in fishing lines with hooks previously thrown into the water by people.

Young Pongo pygmaeus trying to hit the fish with a stick.

The addiction to repeating the behavior of others, rather than inventing new patterns of behavior, leads orangutans to the emergence of local traditions. Thus, all individuals in the population of tool users have certain work skills, although not all often use them. At the same time, members of another population, separated from the craftsmen by just a river, may not possess such abilities, not use certain tools, or use them for other purposes. In addition, in different localities, orangutans use different methods of building nests, make different sounds, and manipulate food in different ways.

According to researchers, learning in orangutan life means no less than innate instincts. Through the transfer of skills, new behaviors may well be inherited from generation to generation. However, the measured and predominantly secluded lifestyle of these primates does not at all contribute to the development and dissemination of acquired skills. This assumption is consistent with the observation that tool activity is much more widespread not among the Kalimantan, but among the more socially developed Sumatran orangutans.

Territoriality

Since orangutans are large animals and have a corresponding appetite, their population density is usually low - about one animal per 1-3 square meters. km, but in fertile river valleys and swampy forests, the density can reach up to 7 individuals per 1 sq. km. On the day, orangutans move from 100 m to 3 km, on average, slightly less than 1 km. In many ways, this distance depends on the territorial status of the animal.

According to the strategy of territorial behavior among orangutans, one can distinguish "residents", "suburbanites" and "wanderers". "Residents" live inside an individual plot with fixed boundaries. Females explore and develop territories with an area of ​​70-900 hectares, sometimes their areas partially overlap. Grown daughters usually stay closer to the mother's territory, but males can wander for years until they settle down. The areas of resident males are much larger - they reach 2500-5000 hectares and often overlap with the areas of several females. Given the current sparseness of the population, individual areas may be even more extensive. Making regular forays within the confines of his possessions, the male seeks not only food, but also a female capable of mating, and also expels other males - reproductive competitors.

Most males, however, do not have fixed sites, being "suburbanites" or "wanderers." “Suburbanites” spend only a few weeks or months in one locality, and then move to a distance of several kilometers from it. Thus, they change their localization many times during the year. In the next year, these males often return to the areas inhabited earlier. Although the territory they are developing in the end turns out to be much larger than that of the "residents", the reproductive advantage of the latter is obvious - they freely mate with females living on the territory of their individual sites. Young sexually mature males, as a rule, are "wanderers". They are not tied to a specific area and do not linger anywhere for a long time, constantly being in motion. Growing up, such a male can establish his site and become a "resident", choose the lifestyle of a "suburbanite" or continue to be a "wanderer".

Social relationships

The orangutan is one of the three most famous great apes. Together with the gorilla and chimpanzee, he is one of the animals closest to man. You can often find an erroneous spelling of the name of this beast - orangutan. But the word "orangutan" in the language of local residents means "debtor", and the word "orangutan" is translated as "forest man". In total, two types of orangutans are known - Bornean and Sumatran.

Bornean orangutan (Pongo pygmaeus).

The appearance of these monkeys is very distinctive and unlike any other animal. In an upright position, the height of orangutans is only 120-140 cm, but the weight can reach 80-140 kg, in rare cases even 180 kg! This is due to the fact that orangutans have relatively short limbs and a thick belly, therefore, with a small size, these animals have a lot of weight. The body of the orangutans is rather square in shape, the limbs are strong and muscular. The arms of orangutans are so long that in an upright position they hang below the knees, but the legs, on the contrary, are short and crooked. The feet and palms are large, and on the hands and feet the big toe is opposed to the rest. This makes it easier to grab branches when climbing trees. At the ends of the fingers, nails are like those of a person. The skull of orangutans is convex with a strongly developed facial part. The eyes are close-set, the nostrils are relatively small. These animals have well-developed facial muscles and they often grimace. In orangutans, sexual dimorphism is well expressed (the difference in the structure of the body of males and females): females are smaller and thinner (up to 50 kg), males are not only heavier, but also have a special ridge of skin around the face. This ridge forms the facial disc, which is especially pronounced in older males; in addition, in males, the mustache and beard are more pronounced on the face. The color of the coat in young animals is fiery red, in older animals it is darker - brown.

The body of orangutans is covered with long, rather sparse hair, which hangs down like a fringe in old animals.

Orangutans live only on the islands of Borneo and Sumatra of the Malay Archipelago, that is, their natural range is relatively small. In nature, these animals inhabit exclusively tropical forests, and they spend most of their lives in trees, rarely descending to the ground. They move through the trees, passing from branch to branch, and where the distance between neighboring trees is large, orangutans use flexible thin trunks or vines. When moving, these monkeys often hang on their hands and generally use the front limbs more actively than the hind ones. Unlike other monkeys, heavy orangutans do not jump from branch to branch. Despite this, in old animals, traces of broken arms and legs are sometimes found.

Orangutans use tree branches as a lodging place: more often they sleep right on the branches, sometimes they build primitive nests in the crowns.

A distinctive feature of these animals is a solitary lifestyle, which is generally not characteristic of primates. Orangutans sharply differ in habits from other species of monkeys: they are extremely quiet and silent, their voices are rarely heard in the forest. Their character is very calm and peaceful. Orangutans never arrange fights, behave imposingly, move slowly. We can say that a certain intelligence is inherent in them. In the forest, each animal has its own area, but the protection of the territory is not associated with aggression. Orangutans avoid human proximity and instead of visiting human settlements in search of food, they seek solitude in the depths of the forest. When caught, they do not offer strong resistance.

Orangutans feed on plant food - leaves and fruits of trees, occasionally they eat eggs of birds and small animals. They collect food in the crowns, slowly plucking and chewing the shoots. Like many monkeys, orangutans do not like water, so they avoid swimming across rivers, and during the rain they cover their heads with torn leaves.

The orangutan scrutinizes the contents of the egg he just ate.

These animals breed all year round. To attract the female, the male begins to roar loudly throughout the forest. If there are several rivals, they try to lure the female to their side with their songs, but they themselves rarely leave the borders of their own area. By sound, the female chooses the strongest gentleman and visits his territory for mating. Pregnancy lasts 8.5 months. The female gives birth to one, rarely two cubs weighing 1.5-2 kg. The newborn is covered with rather long hair and clings tightly to the mother's skin.

The female orangutan lovingly cares for the baby.

First, the female holds the baby on her chest, then the grown baby itself moves onto the mother's back. The mother feeds the baby with milk until 2-3 years old, then he accompanies her for a couple of years. Only at the age of 5-6 years, orangutans begin an independent life. They become sexually mature at the age of 10-15 years, and live on average 45-50. Thus, during her life, a female can raise no more than 5-6 cubs, that is, orangutans are extremely infertile.

A baby orangutan learns to climb vines.

In the natural environment, this does not matter, since large orangutans living on the tops of trees have practically no enemies. Nevertheless, these animals are very rare. The number of orangutans is declining due to the destruction of tropical forests. The already small range of these monkeys has dramatically decreased over the past 40 years. In recent decades, another problem has been added to the destruction of forests - poaching. As orangutans become more rare, their price on the black market rises and more and more hunters go into the forest for their prey. Often, hunters kill the mother just to take away the cub.

An orangutan female with a cub.

Young orangutans are resold to private zoos, but not for breeding. The usual destiny of such animals is to be a toy for people. Taking advantage of the fact that orangutans are very smart, learn quickly and do not show aggression even by adults, they are taught all sorts of tricks, grimaces and even bad habits.