Sea elephant for children. Interesting facts about the sea elephant. Species and habitat
November 7th, 2013
In our age, when humanity has penetrated into space and we are eager to find at least some living organisms on Mars or other planets, one involuntarily wonders: are we properly acquainted with our earthly counterparts? How much do we know about them? Do we know their way of life? Needs? Behavior? Relationship with the outside world?
You don't have to look far for examples. How many of us have seen a live elephant seal? Of course, almost everyone knows that such animals exist. But few people were lucky enough to see in natural conditions these giants, exceeding the size and weight of rhinos, hippos and walruses. Elephant seals live in remote places, namely: in Patagonia - off the coast of Argentina, on the Macquarie Islands - south of Tasmania, on Signy Island, in South Georgia.
So what are these sea elephants?
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First of all, let's say that these are huge pinnipeds mammals belonging to the genus of earless seals (Phocidae), so named in contrast to eared seals- Otariidae. The length of males is from three to six meters, and such a colossus weighs up to two tons! In body shape, these giants resemble walruses, and their skin is just as thick and hard, but they do not have walrus tusks, but they have something like a short thick trunk (which is what elephant seals owe their name to). Very few of these amazing animals have survived to our time. And if we hadn’t realized at the last moment, they would have completely disappeared from the face of the Earth, like their close relatives - sea cows, discovered by naturalist Georg Steller in 1741, during an expedition to the Bering Sea. Having described these huge harmless herbivores, which were easy to shoot thanks to their sluggishness and gullibility, Steller unwittingly showed the way to easy prey for various enterprising people. By 1770 sea cows(later called Steller) no longer existed.
Fortunately, this did not happen to sea elephants. First of all, because they live in areas that are difficult for humans to access: they either swim in the icy water of the polar seas of the southern hemisphere, where, in addition, sharp storm winds never subside, or briefly go to their rookeries located on desert rocky shores Patagonia or on small islands lost in the ocean. In addition, elephant seals, unlike their harmless relatives - dugongs, or sirens, peacefully nibbling sea grass in underwater "meadows", are by no means defenseless animals. Especially the males. Their teeth are sharp and their strength is enormous. The adult male is very aggressive. Sea elephants are predators: they feed on various aquatic animals, mainly fish.
There are two kinds sea elephants: northern (Mirounga angustirostris) and southern (Mirounga leonina). northern view, which differs from the southern one by being narrower and long trunk, lives in California and Mexican waters. Due to predatory fishing in the last century, this species almost completely disappeared. By 1890, only about a hundred northern elephant seals remained, and only the strictest ban on fishing that followed allowed them to increase their number again. In 1960 there were already fifteen thousand of them.
Herds of the southern species were also subjected to ruthless extermination, the former vast range of which is now limited to only a few Antarctic islands, such as Kerguelen, Crozet, Marion, and South Georgia. Several rookeries have survived on Macquarie and Heard Islands. However, in temperate zone, where previously there were also rookeries of these animals - for example, on the southern coast of Chile, on King Island near Tasmania or on the Falkland Islands and the island of Juan Fernandez - now you will not see a single one ...
Today, elephant seals, one might say, have somewhat recovered from past shocks. In some places they even restored their former numbers. But this, of course, only where the animals are under strict protection, for example, on the Argentinean Valdez Peninsula, declared a reserve, or on the Macquarie or Heard Islands, where hunting for them has been prohibited for forty-five years. Animals are clearly thriving there, and their number is growing year by year. As for such islands as South Georgia and Kerguelen, part of the herd is still shot there from time to time. True, it is argued that they do this under strict scientific control.
Why were elephant seals so attractive to hunters? These animals were mined for the sake of one of their subcutaneous fat. Its layer reaches a thickness of fifteen centimeters! It is necessary for the animal to protect it from heat loss in the icy water in which it spends most of its life. And it was this fat that turned out to be so attractive. For its sake, elephant seals were ruthlessly killed, whole mountains of their carcasses rose along the shores, and right there on the shore in huge vats specially installed for this purpose they rendered fat ... On the Patagonian coast of Argentina alone, from 1803 to 1819, North American, English and Dutch fishermen drowned in a total of one million seven hundred and sixty thousand liters of "elephant fat". And this means that the number of animals killed for the sake of this reached no less than four - six thousand! They slaughtered them in the most barbaric way: they cut off the path to the saving water and stabbed them with spears or thrust burning torches into their open mouths ...
And now these huge vats and other equipment for melting fat are still lying along the shores of many islands of Patagonia, rusting in the salty sea wind ... These abandoned vats, as it were, personify the sad memory of the thoughtless and irresponsible exploitation of nature by man in the recent past and serve as a warning to future generations ...
And now, when people have stopped killing elephant seals, it's time to study them. This is done by several groups of scientists from different countries. Very successful observations of the life of these giants were made on the islands of Signy and South Georgia by English biologists under the direction of Dr. R. M. Loves of the British Antarctic Survey; at the same time, Australian scientists, led by Dr. R. Carrick, were working on Macquarie and Heard Islands. The results of their research were published in Canberra in 1964. Somewhat later, the well-known English zoologist John Varham made observations on the same islands.
What did you manage to learn about this rare and little-studied animal?
Despite its colossal size, the elephant seal is a good swimmer. This is facilitated by the spindle shape of his body. The elephant seal is capable of swimming at speeds up to twenty-three kilometers per hour. Moreover, in ice water reliable protection from the cold he is served by a kind of "quilted jacket" - a thick layer of subcutaneous fat. In the water, this overweight animal shows extraordinary maneuverability and dexterity: after all, here it has to get its own food, chasing fish, looking for accumulations of plankton and various crustaceans. The elephant seal is much worse adapted to living on land, although he has to spend a good quarter of his life there. Here it is difficult to imagine a slower and more clumsy animal! He painfully drags his heavy body over stony soil, moving with the help of only the front flippers. At this time, it resembles a huge snail or caterpillar: one “step” is only thirty-five centimeters for a sea elephant! Its own weight, so imperceptible in water, on land becomes an unbearable burden for the animal. It is not surprising that the sea elephant quickly gets tired of the stress, lies down and immediately falls into a heroic, sound sleep. The sleep of the sea elephant is truly sound - in any case, it is not so easy to wake him up. This is explained by the fact that for a very long time these giants had no enemies on land, and they, like rhinos, had no one to be afraid of and there was no need to sleep sensitively.
The deep sleep of elephant seals repeatedly surprised the English zoologist John Warham, who made his observations on Macquarie Island. Every morning, leaving his tent, he came across elephant seals lying side by side in front of the door and blocking his way. They were completely molting young males with a length of three to four and a half meters. They slept quite serenely, their breathing was deep and noisy, sometimes turning even into a rolling snoring. However, it was not difficult for the researcher to get over them: he walked right on their backs, and until the consciousness of these lumps it dawned that they had been walked on in forged boots (which made them raise their heads in fright), the disturber of the peace was already far away ...
No less amazing is the ability of elephant seals to sleep underwater. But how do animals manage to breathe at this time? After all, they have lungs, not gills! .. Scientists managed to find out the secret of such underwater sleep. After a five- or ten-minute stay under water, the chest of the animal expands, while the nostrils remain tightly closed. From this, the density of the body decreases, and it floats. At the surface of the water, the nostrils open, and for about three minutes the animal inhales air. Then it sinks to the bottom again. The eyes remain closed all this time: the elephant is clearly asleep.
Stones are usually found in the stomach of the elephant seal. Residents of the places where these animals live, believe that the stones serve as ballast during the immersion of elephants under water. There are other explanations as well. For example, stones in the stomach can contribute to the grinding of food - whole swallowed fish and crustaceans.
Elephant seals feed mainly on fish, and not at all on cuttlefish, as was previously thought. Cuttlefish in their "menu" is no more than two percent. But on the other hand, an adult sea elephant eats a lot of fish. According to the famous zoologist Hagenbeck, the five-meter sea elephant Goliath, kept in his menagerie, ate an average of fifty kilograms of fish per day! Such reports have led some ichthyologists to argue that the disappearance of elephant seals is a blessing, because they, they say, disputed the catch with fishermen ... However, careful studies have shown the absurdity of such conclusions: the food for elephant seals is mainly small sharks and rays that are not listed commercial fish... On land, during the breeding season, elephant seals are able to fast for weeks: at this time they do not eat anything, but live off their internal fat reserves.
Careful study of these animals in last years opened the veil over many secrets of their life and behavior. In some ways, these clumsy colossi turned out to be a fairly convenient object for the researcher: it cost nothing, for example, to measure their length, calculate the number of individual herds, their composition, age groups, observe the “family” life of these animals, the birth of young animals, etc. d. But try to weigh such a whopper! After all, after all, a male who has risen “on its hind legs” (and this is their usual pose of a threat) becomes as tall as a good column, and even the sight of just one photograph of such a giant inspires awe. Where is the thought of grabbing it and throwing it on the scales! .. No, this is not an easy task - the study of such animals, and one must be a real enthusiast to take on this. After all, we must not forget about climatic features places where these observations are made: about continuous prickly winds, icy water, bare, inhospitable rocky landscape ... And yet, the researchers managed to conduct a very important work, which made it possible not only to determine the age of individual individuals, but also to trace their migrations, seasonal changes composition of herds, the process of molting, relationships in the herd.
But let's start in order. For four years, Australian explorers on the Heard and Macquarie Islands have been systematically branding baby elephant seals, much like domestic calves or foals are. By 1961, almost seven thousand baby elephants had been tagged. This subsequently made it possible to accurately determine the age of one or another animal, the order in which different age groups appear on the rookery, the attachment of individual individuals to their “homeland” or the tendency to change places ... So, the female under the number “M-102” four years in a row brought offspring in the same place and only in the fifth year moved half a kilometer further. Other patterns emerged as well. For example, "adolescent" groups of elephant seals appear on the rookery much later than the adults involved in breeding, which usually falls between August and mid-November. Molting in animals of different age groups also occurs in different time. Thus, the rookery is almost never empty - only the contingent of its inhabitants changes.
Among the males, four groups can be clearly distinguished. The first - "teenage" - includes animals aged from one to six years, their size does not exceed three meters. They appear on the rookery in winter, especially after storms, with the clear purpose of taking a break from swimming. These animals are the earliest to molt - in December (the beginning of summer in southern hemisphere), and then all the other animals appear in order of seniority: the older, the later.
The second, or “youthful”, group is formed by animals aged from six to thirteen years, their sizes are from three to four and a half meters. They come to the beach in autumn, shortly after the females have cubs, but they do not fight with older males, and even before the start of the rut (after the cubs are weaned) they swim out to sea.
The next age group is the so-called applicants. Such males, ranging in size from four and a half to six meters, with a proudly swollen trunk, are in a constantly aggressive mood and climb to fight with the owners of the rookery - the owners of "harems" - powerful old males, trying to beat off some of the females from them. These old experienced males make up the fourth age group.
Such a "harem" owner is a very imposing figure. He is huge, imposing, jealous and aggressive. If he were otherwise, he would not have been able to hold on to his “post”. After all, the “harem” usually consists of several dozen females, and in order to keep in obedience all these curious, striving to scatter in different directions and “flirting” with any “applicant” that has appeared, you need remarkable strength and an unsleeping eye ... Seeing an opponent, the owner " harem" emits an evil roar and rushes towards him, crushing everything that comes in his way: knocking over females and trampling cubs ... Such a "master" in general, as a rule, is an extremely "insensitive" animal. It often happens that he crushes newborn cubs to death. A case is described when a male lay down to sleep, crushing a desperately screaming cub under him, but did not even think of getting up to free the unfortunate one.
If the “harem” turns out to be large for one owner, he is forced to allow “assistants” into his territory who guard its remote areas ...
Observations have shown that the same old and strong male dominates the "harem" during the entire breeding season, and younger and weaker males are often forced to give up their place to a rival superior in strength to them. Although the fights of males are usually played out in the water, not far from the coast, panic also begins on the beach at this time - alarmed females scream, cubs try to escape. Therefore, from "harems", where they are disturbed too often, females try to move to calmer "harems".
The fight of males is an impressive sight. Rivals, having swum up to each other, rise “on their hind legs”, towering four meters above the shallow water, and freeze in this position for several minutes, resembling stone statues of monsters. Animals emit a dull roar, their trunks swell menacingly, irrigating the enemy with a cascade of spray. After such a presentation, the weaker enemy usually retreats backwards, continuing to roar menacingly, and, having moved to a safe distance, takes to his heels. The winner, on the other hand, lets out a proud cry and, having made several false throws in pursuit of the fugitive, calms down and returns to the beach.
When none of the opponents is going to give in, the fight flares up in earnest. Then both powerful bodies resoundingly hit each other, with a quick and sharp movement of the head, each tries to sink his fangs into the neck of the enemy. However, the skin of the seal is so hard and slippery, and even provided with a thick cushion of subcutaneous fat, that it rarely comes to serious injuries. True, scars and scars remain on the neck of males for life, but that's all.
No matter how intimidating such a battle may look from the outside, in most cases it does not come to serious bloodshed. Usually everything is limited to mutual intimidation, frightening roar and sniffling. The biological meaning of such behavior is clear: the strongest is revealed, which will take over the functions of the producer during mating season and how the successor of the family will pass on to their offspring positive traits. At the same time, the weaker young male does not die on the battlefield and is thus not excluded from the further process of reproduction of the species...
When individual plots and “harems” have already been distributed, there are practically no battles between male neighbors: if someone violates territorial integrity, it is enough for the “owner” to rise and growl so that the border violator immediately leaves.
In relation to humans, tall males do not always show aggressiveness. And not they, but just the females can be the most dangerous for the researcher who dared to penetrate into the very thick of the herd. John Warham, for example, more than once had to get acquainted with their sharp teeth and it’s shameful to run away, leaving a good piece of his trouser leg to the angry sea elephant as a keepsake…
It is worth talking about females in more detail. Females are much smaller than males - rarely they reach three meters in length and a ton of weight. They grow slowly, but physically develop faster than males: by the age of two or three they become sexually mature, while males reach sexual maturity much later.
The breeding season lasts from August to mid-November. Females appear on the rookery already "on demolition" and in five days they bring offspring. Most cubs will be born from late September to mid-October. The owners of "harems" vigilantly protect the females during the period of offspring.
Both females and males arrive at the beach well-fed after a thorough fattening in the sea. This is necessary for a long "fast" that they have to endure on land: males "fast" for up to two weeks, and females even for a whole month! But during this time, the females will have to endure all the hardships associated with childbirth and feeding the cubs, and the males - the stress of the subsequent mating season and the associated fights with rivals.
Having appeared on the beach and preparing for childbirth, the females are located at some distance from each other, and do not lie closely side by side, as in regular time. The birth itself lasts only about twenty minutes, and the cub is born already sighted. Moreover, he is very pretty: covered with wavy black fur and looks at the world around him with huge radiant eyes. But the "baby" weighs about fifty kilograms, and reaches a length of one and a half meters, that is, the size of an adult seal ...
Having been born, the cub emits a short bark, reminiscent of a dog, the mother responds to him in the same way, sniffs him and thus remembers. Subsequently, she will unmistakably distinguish him among many other cubs and will be able to return if he makes an attempt to escape.
The upcoming birth can be immediately determined by the fact that loud-mouthed large brown birds, which in some areas are called skua, are circling over the woman in labor. These birds labor in the role of "midwives" for sea elephants. With extraordinary agility, they remove the birth membranes and the placenta, and on occasion they can cope with a stillborn cub. Skua is not averse to treating himself to milk spilled on the ground by lactating females.
This milk is extremely nutritious (almost half consists of fat), and the cubs grow up with unprecedented speed: they add from five to twelve kilograms a day! In the first eleven days they double their weight, and in two and a half weeks they triple it. True, they add a little in length, but they build up an impressive fat layer - seven and a half centimeters, which they will need first of all: it should protect their body from hypothermia during the upcoming long stay in the water.
After about a month, the cubs, or "kohoro" as they are called in Patagonia, the females stop feeding. By this time, their "baby" black fur has been replaced by silver-gray, they look very plump and contented. Soon they leave the "harem", crawling into the depths of the beach, where they lie down and build up their muscles. At the age of five weeks, the young begin their first timid swimming attempts. On quiet windless evenings, elephant seals clumsily descend into the water of the lagoons heated by the sun or the barrels left after low tide and carefully swim near the shore. Gradually they become more confident and bolder, venture on longer sea excursions, until nine weeks old they finally leave their native rookery and swim away into the distance ...
And again, one has only to wonder how rationally everything is arranged in nature. Young growth becomes independent precisely at the time when the prospects for its survival are most favorable. Just at this time, the surface of the sea is covered with a particularly thick layer of plankton, and young elephant seals are provided with easily accessible and high-calorie food for several months.
However, control over labeled animals has shown something else: half of the cubs die in the first year of their lives. Later, losses are significantly reduced, and about forty percent of the young already reach the age of four.
Based on these data, Australian experts have come to the following important conclusions. If it is necessary to shoot some part of the herd of elephant seals (due to overcrowding of the rookery, lack of food, etc.), then it should be young animals aged from five weeks to one year. But it is absolutely unacceptable to shoot adult males, as was once practiced in South Georgia, where about six thousand of them were killed once in one summer. Without proper guarding of the "harems" by old experienced males, the herds fall into decline, because the young males begin to fight with each other incessant battles, challenging the primacy. This is what incompetent human intervention in the affairs of nature leads to, and therefore rash actions without sufficient scientific justification should be avoided.
But let's go back to the elephant seal rookery, where the young have just left. After the "weaning" of the cubs, the females mate again with the owner of the "harem" and soon after that they go to sea - to take a break from the hardships of childbirth, eat well and build up a new layer of fat until their next appearance on the rookery - in February, during the molting period.
And here we should mention one of the most amazing adaptations of the animal organism to the conditions of existence: the development of the embryo in the womb of the female is temporarily suspended, and the embryo is, as it were, "preserved" for the entire unfavorable period of the animal's life - in this case, during molting. (A similar phenomenon is observed in some other animals - many pinnipeds, as well as in sable, rabbit, kangaroo, etc.) The development of the embryo continues only in March, when the molt in females is already over.
Powerful males, the owners of the beach, come to molt much later - around the beginning of April. The intense life on the rookery requires a longer recovery of strength.
As already mentioned, the younger ones appear first, and later the older ones. During molting, age groups stay together, but by gender: females with females, and males with males. The molt lasts, depending on age, one to two months. Until the end of it, the animals will never start swimming, because at this time the sensitive blood vessels of the skin are greatly expanded and a sharp cooling can cause a violation of the thermoregulation mechanism, which means inevitable death in ice water.
The appearance of a molting elephant seal is the most deplorable: the old skin hangs on it in torn rags. First, she gets off the muzzle, and then from the rest of the body. At the same time, the poor fellows scratch their sides and stomach with flippers, trying to speed up this process, which is clearly unpleasant for them ...
Moulting animals are usually located in some moss-covered swamp, not far from the coast, and, restlessly tossing and turning, stir up loose soil, turning it into a dirty mess. In it, they are immersed to the very nostrils. The stench around is terrifying at this time. So not every tourist is able to withstand it ... By the way, about tourists visiting reserved places. As already mentioned, the Argentine government has declared the small peninsula of Valdes in the north of Patagonia a protected area. On this peninsula, a colony of elephant seals settled, numbering several hundred heads. It is called "elephanterium" (elephant), and with recently is open to visitors. One hundred and sixty-five kilometers from the rookery, the resort town of Puerto Madryn arose. And since the water here is often too cold for swimming, many vacationers willingly take excursions to the "elephantry". They offer paid tour guides. In addition, the tourist route, which runs through a number of South American countries, includes a visit to the Valdes Peninsula with its elephant seal rookery. The ever-increasing flow of tourists, loudly expressing their delight and constantly clicking cameras, certainly unnerves the animals, disrupts their usual way of life, especially at a time when females bring offspring. Males - the owners of "harems" here began to behave much more aggressively than usual. They angrily rush towards annoying visitors, trying to drive them away from "their" territory, or drive their entire "harem" into the water...
There are 2 species in the genus:
southern elephant seal - M. leonina Linnaeus, 1758 (subantarctic waters circumpolar north to 16°S and south to Antarctic pack ice - 78°S; breeds off Punta Norte and Tierra del Fuego in Argentina and islands of Falkland, South Shetland, South Orkney, South Georgia, South Sandwich, Gough, Marion, Prince Edward, Crozet, Kerguelen, Hurd, Macquarie, Auckland, Campbell);
northern elephant seal - M. angustirostris Gill, 1866 (islands off the coast of Mexico and California to the north to the Vancouver Islands and Prince Wales; breeds on the islands of San Nicolas, San Miguel, Guadalupe and San Benito).
The northern elephant seal was close to extinction by overfishing, but in recent times thanks to the prohibition of fishing, its numbers have increased significantly and continue to increase.
The total number of southern elephant seals is determined at 600-700 thousand heads, and northern ones - only 10-15 thousand heads.
Southern elephant seals are hunted on coastal haulouts, and there are restrictions on fishing for the seasons, the size of the hunted seals at least 3.5 m long and their number. For example, in 1951, 8,000 elephant seals were allowed to be harvested; mined 7877. Fat and skin are obtained from the mined animals.
The southern elephant seal belongs to the family of true seals. In terms of size, they take the second place among all pinnipeds, yielding in size only to the northern elephant seal. Even the indigenous inhabitant of the Arctic, the walrus, loses in all respects and is in an honorable third place. The largest representatives of the southern giants reach a length of 6.5 meters and weigh 3.5 tons. The usual length of the male is 5.5 meters with a mass of 2.5 tons.
The females are noticeably smaller. Their length does not exceed 3.5 meters, the weight rarely reaches one and a half tons. The hallmark of this huge seal is the trunk: a leather fold located on the upper part of the muzzle in males - females do not have such a formation. In a calm state, it reaches a length of 10 cm. When the elephant is excited, the muscles of the fold tighten, and the trunk increases to 25-30 cm. Due to its size, as well as the trunk, this animal was called the sea elephant.
Appearance
The animal has rough wrinkled skin. From above it is covered with sparse, hard and short dark brown fur. During the molt, which begins in December and lasts a month and a half, the old skin becomes blistered and slides off the body in long, wide strips. This process is very painful and unpleasant. The elephant lies on the ground and does not eat anything. He is very thin and weak. But after the renewal of the skin, it immediately rushes to the sea, where it quickly restores its strength.
Newborns are born with black fur. And it is not rare, but dense. Upon reaching 2 months, the color of the fur changes to light gray. The body of the southern elephant seal is covered with a thick layer of subcutaneous fat. It reaches a thickness of 10 cm, and its mass, in relation to body weight, is 35%. Fat protects internal organs from hypothermia and improves the buoyancy of the animal.
Habitat
Southern elephant seals make their rookeries in the Falkland, South Orkney and South Shetland Islands. They also love South Georgia, Heard and the Kerguelen Islands. Macquarie Island to the south Pacific Ocean also lies in their area of interest. On the shores covered with pebbles and sand, animals spend a long six months. Up to 10 thousand individuals gather in one place, forming huge rookeries.
Here they mate, give birth to cubs and molt. After molting, they swim to the open ocean, where they can live for many days without seeing land. southern elephant seal great swimmer, he is able to overcome huge sea distances. It can swim both 4 and 5 thousand kilometers to find itself in the zone of Antarctic pack ice or off the coast. South Africa and New Zealand. This animal dives to a depth of 500 meters, it can stay under water for 40 minutes.
Reproduction and lifespan
Animals begin to arrive at the rookeries by the beginning of spring. This is the end of August - the first decade of September (in the southern hemisphere, summer comes in December, and winter in June). At first, pregnant females appear on the rocky shores. Males pull up later. Fights immediately start between them. Sometimes they turn into whole bloody battles, since elephant seals have quite powerful front fangs.
In the end, everything calms down, and each male finds a harem. It can include 10 females, and a hundred. It all depends on the strength and aggression of the male. Babies are born in September and October. Females crawl away to give birth in secluded places. The cub is born alone. The length of his body reaches a meter, and the mass is 25-30 kg.
The mother feeds the baby with milk for a month. Then she returns to the male and becomes pregnant again. The gestation period is 11 months, that is, almost a year. The kid is left alone. He grows up without the supervision of his mother. When he is 3 months old, he swims with his peers to the open ocean. After molting, at the end of February, adult animals also leave the rookery until the next spring. Sexual maturity in males occurs at 4 years, in females at 2 years. The female gives birth every year for 10-12 years. These animals live on average 20 years.
Enemies
The southern elephant seal feeds on fish, cephalopods and mollusks. He himself becomes a victim of killer whales. These huge predators attack him both in coastal and open ocean waters. But since they do not like to move further than 800 km from the coast, a huge seal, having overcome this distance, is completely safe. Baby elephant seals are attacked by leopard seals.
Another enemy is man. In past centuries, he mercilessly destroyed harmless animals for their fat. From one killed elephant seal, at least 500 kg of a valuable product were obtained. Nowadays, the fishing of these animals is prohibited. As a result, their number has increased. The number of southern elephant seals today is 750 thousand heads. At least 250 thousand animals live on the island of South Georgia, the same number on the Kerguelen Islands. These are the largest rookeries of huge seals, which they share with penguins.
♦ ♦ ♦In our age, when humanity has penetrated outer space and we are eager to find at least some living organisms on Mars or other planets, one involuntarily wonders: are we properly acquainted with our earthly counterparts? How much do we know about them? Do we know their way of life? Needs? Behavior? Relationship with the outside world?
You don't have to look far for examples. How many of us have seen a live elephant seal? Of course, almost everyone knows that such animals exist. But few people were lucky enough to see these giants in natural conditions, exceeding the size and weight of rhinos, hippos and walruses. Elephant seals live in remote places, namely: in Patagonia - off the coast of Argentina, on the Macquarie Islands - south of Tasmania, on Signy Island, in South Georgia.
To begin with, let's say that these are huge pinnipeds mammals belonging to the genus of earless seals (Phocidae), named so in contrast to eared seals - Otariidae. The length of males is from three to six meters, and such a colossus weighs up to two tons! In body shape, these giants resemble walruses, and their skin is just as thick and hard, but they do not have walrus tusks, but they have something like a short thick trunk (which is what elephant seals owe their name to). Very few of these amazing animals have survived to our time. And if we hadn’t realized at the last moment, they would have completely disappeared from the face of the Earth, like their close relatives - sea cows, discovered by naturalist Georg Steller in 1741, during an expedition to the Bering Sea. Having described these huge harmless herbivores, which were easy to shoot thanks to their sluggishness and gullibility, Steller unwittingly showed the way to easy prey for various enterprising people. By 1770, sea cows (later called Steller's) no longer existed.
Fortunately, this did not happen to sea elephants. First of all, because they live in areas that are inaccessible to humans: they either swim in the icy water of the polar seas of the southern hemisphere, where, in addition, sharp storm winds never subside, or briefly get out to their rookeries located on the desert rocky shores of Patagonia or on small lost islands in the ocean. In addition, elephant seals, unlike their harmless relatives - dugongs, or sirens, peacefully nibbling sea grass in underwater "meadows", are by no means defenseless animals. Especially the males. Their teeth are sharp and their strength is enormous. The adult male is very aggressive. Sea elephants are predators: they feed on various aquatic animals, mainly fish.
There are two species of elephant seals: northern (Mirounga angustirostris) and southern (Mirounga leonina). The northern species, which differs from the southern one in a narrower and longer trunk, lives in California and Mexican waters. Due to predatory fishing in the last century, this species almost completely disappeared. By 1890, only about a hundred northern elephant seals remained, and only the strictest ban on fishing that followed allowed them to increase their number again. In 1960 there were already fifteen thousand of them.
Herds of the southern species were also subjected to ruthless extermination, the former vast range of which is now limited to only a few Antarctic islands, such as Kerguelen, Crozet, Marion, and South Georgia. Several rookeries have survived on Macquarie and Heard Islands. However, in the temperate zone, where rookeries of these animals were also found before - for example, on the southern coast of Chile, on King Island near Tasmania or on the Falkland Islands and the island of Juan Fernandez - now you will not see a single ...
Today, elephant seals, one might say, have somewhat recovered from past shocks. In some places they even restored their former numbers. But this, of course, only where the animals are under strict protection, for example, on the Argentinean Valdez Peninsula, declared a reserve, or on the Macquarie or Heard Islands, where hunting for them has been prohibited for forty-five years. Animals are clearly thriving there, and their number is growing year by year. As for such islands as South Georgia and Kerguelen, part of the herd is still shot there from time to time. True, it is argued that they do this under strict scientific control.
Why were elephant seals so attractive to hunters? These animals were mined for the sake of one of their subcutaneous fat. Its layer reaches a thickness of fifteen centimeters! It is necessary for the animal to protect it from heat loss in the icy water in which it spends most of its life. And it was this fat that turned out to be so attractive. For its sake, elephant seals were ruthlessly killed, whole mountains of their carcasses rose along the shores, and right there on the shore in huge vats specially installed for this purpose they rendered fat ... On the Patagonian coast of Argentina alone, from 1803 to 1819, North American, English and Dutch fishermen drowned in a total of one million seven hundred and sixty thousand liters of "elephant fat". And this means that the number of animals killed for the sake of this reached no less than four - six thousand! They slaughtered them in the most barbaric way: they cut off the path to the saving water and stabbed them with spears or thrust burning torches into their open mouths ...
And now these huge vats and other equipment for melting fat are still lying along the shores of many islands of Patagonia, rusting in the salty sea wind ... These abandoned vats, as it were, personify the sad memory of the thoughtless and irresponsible exploitation of nature by man in the recent past and serve as a warning to future generations ...
And now, when people have stopped killing elephant seals, it's time to study them. This is done by several groups of scientists from different countries. Very successful observations of the life of these giants were made on the islands of Signy and South Georgia by English biologists under the direction of Dr. R. M. Loves of the British Antarctic Survey; at the same time, Australian scientists, led by Dr. R. Carrick, were working on Macquarie and Heard Islands. The results of their research were published in Canberra in 1964. Somewhat later, the well-known English zoologist John Varham made observations on the same islands.
What did you manage to learn about this rare and little-studied animal?
Despite its colossal size, the elephant seal is a good swimmer. This is facilitated by the spindle shape of his body. The elephant seal is capable of swimming at speeds up to twenty-three kilometers per hour. Moreover, in icy water, a kind of “quilted jacket” - a thick layer of subcutaneous fat - serves as a reliable protection from the cold. In the water, this overweight animal shows extraordinary maneuverability and dexterity: after all, here it has to get its own food, chasing fish, looking for accumulations of plankton and various crustaceans. The elephant seal is much worse adapted to living on land, although he has to spend a good quarter of his life there. Here it is difficult to imagine a slower and more clumsy animal! He painfully drags his heavy body over stony soil, moving with the help of only the front flippers. At this time, it resembles a huge snail or caterpillar: one “step” is only thirty-five centimeters for a sea elephant! Its own weight, so imperceptible in water, on land becomes an unbearable burden for the animal. It is not surprising that the sea elephant quickly gets tired of the stress, lies down and immediately falls into a heroic, sound sleep. The dream of the sea elephant is truly unbreakable - in any case, it is not so easy to wake him up. This is explained by the fact that for a very long time these giants had no enemies on land, and they, like rhinos, had no one to be afraid of and there was no need to sleep sensitively.
The deep sleep of elephant seals repeatedly surprised the English zoologist John Warham, who made his observations on Macquarie Island. Every morning, leaving his tent, he came across elephant seals lying side by side in front of the door and blocking his way. They were completely molting young males with a length of three to four and a half meters. They slept quite serenely, their breathing was deep and noisy, sometimes turning even into a rolling snoring. However, it was not difficult for the researcher to get over them: he walked right on their backs, and until the consciousness of these lumps it dawned that they had been walked on in forged boots (which made them raise their heads in fright), the disturber of the peace was already far away ...
No less amazing is the ability of elephant seals to sleep underwater. But how do animals manage to breathe at this time? After all, they have lungs, not gills! .. Scientists managed to find out the secret of such underwater sleep. After a five- or ten-minute stay under water, the chest of the animal expands, while the nostrils remain tightly closed. From this, the density of the body decreases, and it floats. At the surface of the water, the nostrils open, and for about three minutes the animal inhales air. Then it sinks to the bottom again. The eyes remain closed all this time: the elephant is clearly asleep.
Stones are usually found in the stomach of the elephant seal. Residents of the places where these animals live, believe that the stones serve as ballast during the immersion of elephants under water. There are other explanations as well. For example, stones in the stomach can contribute to the grinding of food - whole swallowed fish and crustaceans.
Elephant seals feed mainly on fish, and not at all on cuttlefish, as was previously thought. Cuttlefish in their "menu" is no more than two percent. But on the other hand, an adult sea elephant eats a lot of fish. According to the famous zoologist Hagenbeck, the five-meter sea elephant Goliath, kept in his menagerie, ate an average of fifty kilograms of fish per day! Such reports led some ichthyologists to argue that the disappearance of elephant seals is a blessing, because they, they say, disputed the catch with fishermen ... However, careful studies have shown the absurdity of such conclusions: the food of elephant seals is mainly small sharks and rays that are not listed commercial fish ... On land, during the breeding season, elephant seals are able to fast for weeks: at this time they do not eat anything, but live off their internal fat reserves.
Careful study of these animals in recent years has lifted the veil over many secrets of their life and behavior. In some ways, these clumsy colossi turned out to be a fairly convenient object for the researcher: it cost nothing, for example, to measure their length, calculate the number of individual herds, their composition, age groups, observe the “family” life of these animals, the birth of young animals, etc. d. But try to weigh such a whopper! After all, after all, a male who has risen “on its hind legs” (and this is their usual pose of a threat) becomes as tall as a good column, and even the sight of just one photograph of such a giant inspires awe. Where is the thought of grabbing it and throwing it on the scales! .. No, this is not an easy task - the study of such animals, and one must be a real enthusiast to take on this. After all, one should not forget about the climatic features of the places where these observations are made: about continuous prickly winds, icy water, bare, inhospitable rocky landscape ... And yet, the researchers managed to carry out very important work, which made it possible not only to determine the age of individual individuals, but also to trace their migrations, seasonal changes in the composition of herds, the process of molting, relationships in the herd.
But let's start in order. For four years, Australian explorers on the Heard and Macquarie Islands have been systematically branding baby elephant seals, much like domestic calves or foals are. By 1961, almost seven thousand baby elephants had been tagged. This subsequently made it possible to accurately determine the age of one or another animal, the order in which different age groups appear on the rookery, the attachment of individual individuals to their “homeland” or the tendency to change places ... So, the female under the number “M-102” four years in a row brought offspring in the same place and only in the fifth year moved half a kilometer further. Other patterns emerged as well. For example, "adolescent" groups of elephant seals appear on the rookery much later than the adults involved in breeding, which usually falls between August and mid-November. Molting in animals of different age groups also occurs at different times. Thus, the rookery is almost never empty - only the contingent of its inhabitants changes.
Among the males, four groups can be clearly distinguished. The first - "teenage" - includes animals aged from one to six years, their size does not exceed three meters. They appear on the rookery in winter, especially after storms, with the clear purpose of taking a break from swimming. These animals are the earliest to molt - in December (the beginning of summer in the southern hemisphere), and then all other animals appear in order of seniority: the older, the later.
The second, or “youthful”, group is formed by animals aged from six to thirteen years, their sizes are from three to four and a half meters. They come to the beach in autumn, shortly after the females have cubs, but they do not fight with older males, and even before the start of the rut (after the cubs are weaned) they swim out to sea.
The next age group is the so-called applicants. Such males, ranging in size from four and a half to six meters, with a proudly swollen trunk, are in a constantly aggressive mood and climb to fight with the owners of the rookery - the owners of "harems" - powerful old males, trying to beat off some of the females from them. These old experienced males make up the fourth age group.
Such an owner of the "harem" is a very imposing figure. He is huge, imposing, jealous and aggressive. If he were otherwise, he would not have been able to hold on to his “post”. After all, the “harem” usually consists of several dozen females, and in order to keep in obedience all these curious, striving to scatter in different directions and “flirting” with any “applicant” that has appeared, you need remarkable strength and an unsleeping eye ... Seeing an opponent, the owner " harem" emits an evil roar and rushes towards him, crushing everything that comes in his way: knocking over females and trampling cubs ... Such a "master" in general, as a rule, is an extremely "insensitive" animal. It often happens that he crushes newborn cubs to death. A case is described when a male lay down to sleep, crushing a desperately screaming cub under him, but did not even think of getting up to free the unfortunate one.
If the “harem” turns out to be large for one owner, he is forced to allow “assistants” into his territory who guard its remote areas ...
Observations have shown that the same old and strong male dominates the "harem" during the entire breeding season, and younger and weaker males are often forced to give up their place to a rival superior in strength to them. Although the fights of males are usually played out in the water, not far from the coast, panic also begins on the beach at this time - alarmed females scream, cubs try to escape. Therefore, from "harems", where they are disturbed too often, females try to move to calmer "harems".
The fight of males is an impressive sight. Rivals, having swum up to each other, rise “on their hind legs”, towering four meters above the shallow water, and freeze in this position for several minutes, resembling stone statues of monsters. Animals emit a dull roar, their trunks swell menacingly, irrigating the enemy with a cascade of spray. After such a presentation, the weaker enemy usually retreats backwards, continuing to roar menacingly, and, having moved to a safe distance, takes to his heels. The winner, on the other hand, lets out a proud cry and, having made several false throws in pursuit of the fugitive, calms down and returns to the beach.
When none of the opponents is going to give in, the fight flares up in earnest. Then both powerful bodies resoundingly hit each other, with a quick and sharp movement of the head, each tries to sink his fangs into the neck of the enemy. However, the skin of the seal is so hard and slippery, and even provided with a thick cushion of subcutaneous fat, that it rarely comes to serious injuries. True, scars and scars remain on the neck of males for life, but that's all.
No matter how intimidating such a battle may look from the outside, in most cases it does not come to serious bloodshed. Usually everything is limited to mutual intimidation, frightening roar and sniffling. The biological meaning of such behavior is clear: the strongest is revealed, who will take over the functions of the producer during the mating season and, as the successor of the family, will pass on his positive qualities to the offspring. At the same time, the weaker young male does not die on the battlefield and is thus not excluded from the further process of reproduction of the species...
When individual plots and “harems” have already been distributed, there are practically no battles between male neighbors: if someone violates territorial integrity, it is enough for the “owner” to rise and growl so that the border violator immediately leaves.
In relation to humans, tall males do not always show aggressiveness. And not they, but just the females can be the most dangerous for the researcher who dared to penetrate into the very thick of the herd. John Varham, for example, more than once had to get acquainted with their sharp teeth and shamefully run away, leaving a good piece of his trouser leg to the angry sea elephant as a keepsake...
It is worth talking about females in more detail. Females are much smaller than males - rarely they reach three meters in length and a ton of weight. They grow slowly, but physically develop faster than males: by the age of two or three they become sexually mature, while males reach sexual maturity much later.
The breeding season lasts from August to mid-November. Females appear on the rookery already "on demolition" and in five days they bring offspring. Most cubs will be born from late September to mid-October. The owners of "harems" vigilantly protect the females during the period of offspring.
Both females and males arrive at the beach well-fed after a thorough fattening in the sea. This is necessary for a long "fast" that they have to endure on land: males "fast" for up to two weeks, and females even for a whole month! But during this time, the females will have to endure all the hardships associated with childbirth and feeding the cubs, and the males - the stress of the subsequent mating season and the associated fights with rivals.
Having appeared on the beach and preparing for childbirth, the females are located at some distance from each other, and do not lie closely side by side, as in normal times. The birth itself lasts only about twenty minutes, and the cub is born already sighted. Moreover, he is very pretty: covered with wavy black fur and looks at the world around him with huge radiant eyes. But the "baby" weighs about fifty kilograms, and reaches a length of one and a half meters, that is, the size of an adult seal ...
Having been born, the cub emits a short bark, reminiscent of a dog, the mother responds to him in the same way, sniffs him and thus remembers. Subsequently, she will unmistakably distinguish him among many other cubs and will be able to return if he makes an attempt to escape.
The upcoming birth can be immediately determined by the fact that loud-mouthed large brown birds, which in some areas are called skua, are circling over the woman in labor. These birds labor in the role of "midwives" for sea elephants. With extraordinary agility, they remove the birth membranes and the placenta, and on occasion they can cope with a stillborn cub. Skua is not averse to treating himself to milk spilled on the ground by lactating females.
This milk is extremely nutritious (almost half consists of fat), and the cubs grow up with unprecedented speed: they add from five to twelve kilograms a day! In the first eleven days they double their weight, and in two and a half weeks they triple it. True, they add a little in length, but they build up an impressive fat layer - seven and a half centimeters, which they will need first of all: it should protect their body from hypothermia during the upcoming long stay in the water.
After about a month, the cubs, or "kohoro" as they are called in Patagonia, the females stop feeding. By this time, their "baby" black fur has been replaced by silver-gray, they look very plump and contented. Soon they leave the "harem", crawling into the depths of the beach, where they lie down and build up their muscles. At the age of five weeks, the young begin their first timid swimming attempts. On quiet windless evenings, elephant seals clumsily descend into the water of the lagoons heated by the sun or the barrels left after low tide and carefully swim near the shore. Gradually they become more confident and bolder, venture on longer sea excursions, until nine weeks old they finally leave their native rookery and swim away into the distance ...
And again, one has only to wonder how rationally everything is arranged in nature. Young growth becomes independent precisely at the time when the prospects for its survival are most favorable. Just at this time, the surface of the sea is covered with a particularly thick layer of plankton, and young elephant seals are provided with easily accessible and high-calorie food for several months.
However, control over labeled animals has shown something else: half of the cubs die in the first year of their lives. Later, losses are significantly reduced, and about forty percent of the young already reach the age of four.
Based on these data, Australian experts have come to the following important conclusions. If it is necessary to shoot some part of the herd of elephant seals (due to overcrowding of the rookery, lack of food, etc.), then it should be young animals aged from five weeks to one year. But it is absolutely unacceptable to shoot adult males, as was once practiced in South Georgia, where about six thousand of them were killed once in one summer. Without proper guarding of the "harems" by old experienced males, the herds fall into decline, because the young males begin to fight with each other incessant battles, challenging the primacy. This is what incompetent human intervention in the affairs of nature leads to, and therefore rash actions without sufficient scientific justification should be avoided.
But let's go back to the elephant seal rookery, where the young have just left. After the "weaning" of the cubs, the females mate again with the owner of the "harem" and soon after that they go to sea - to take a break from the hardships of childbirth, eat well and build up a new layer of fat until their next appearance on the rookery - in February, during the molting period.
And here we should mention one of the most amazing adaptations of the animal organism to the conditions of existence: the development of the embryo in the womb of the female is temporarily suspended, and the embryo is, as it were, "preserved" for the entire unfavorable period of the animal's life - in this case, during molting. (A similar phenomenon is observed in some other animals - many pinnipeds, as well as in sable, rabbit, kangaroo, etc.) The development of the embryo continues only in March, when the molt in females is already over.
Powerful males, the owners of the beach, come to molt much later - around the beginning of April. The intense life on the rookery requires a longer recovery of strength.
As already mentioned, the younger ones appear first, and later the older ones. During molting, age groups stay together, but by gender: females with females, and males with males. The molt lasts, depending on age, one to two months. Until the end of it, the animals will never start swimming, because at this time the sensitive blood vessels of the skin are greatly expanded and a sharp cooling can cause a violation of the thermoregulation mechanism, which means inevitable death in ice water.
The appearance of a molting elephant seal is the most deplorable: the old skin hangs on it in torn rags. First, she gets off the muzzle, and then from the rest of the body. At the same time, the poor fellows scratch their sides and stomach with flippers, trying to speed up this process, which is clearly unpleasant for them ...
Moulting animals are usually located in some moss-covered swamp, not far from the coast, and, restlessly tossing and turning, stir up loose soil, turning it into a dirty mess. In it, they are immersed to the very nostrils. The stench around is terrifying at this time. So not every tourist is able to withstand it ... By the way, about tourists visiting reserved places. As already mentioned, the Argentine government has declared the small peninsula of Valdes in the north of Patagonia a protected area. On this peninsula, a colony of elephant seals settled, numbering several hundred heads. It is called "elephantery" (elephant), and recently it has been open to visitors. One hundred and sixty-five kilometers from the rookery, the resort town of Puerto Madryn arose. And since the water here is often too cold for swimming, many vacationers willingly take excursions to the "elephantry". They offer paid tour guides. In addition, the tourist route, which runs through a number of South American countries, includes a visit to the Valdes Peninsula with its elephant seal rookery. The ever-increasing flow of tourists, loudly expressing their delight and constantly clicking cameras, certainly unnerves the animals, disrupts their usual way of life, especially at a time when females bring offspring. Males - the owners of "harems" here began to behave much more aggressively than usual. They angrily rush towards annoying visitors, trying to drive them away from "their" territory, or drive their entire "harem" into the water...
There are 2 species in the genus:
southern elephant seal - M. leonina Linnaeus, 1758 (subantarctic waters circumpolar north to 16 ° S and south to Antarctic pack ice - 78 ° S; breeds near Punta Norte and Tierra del Fuego in Argentina and on islands of Falkland, South Shetland, South Orkney, South Georgia, South Sandwich, Gough, Marion, Prince Edward, Crozet, Kerguelen, Heard, Macquarie, Auckland, Campbell);
northern elephant seal - M. angustirostris Gill, 1866 (islands off the coast of Mexico and California north to the Vancouver Islands and Prince Wales; breeds on the islands of San Nicolas, San Miguel, Guadalupe and San Benito).
Until recently, the northern elephant seal was close to being destroyed by overfishing, but recently, thanks to the prohibition of fishing, its numbers have increased significantly and continue to increase.
The total number of southern elephant seals is estimated at 600-700 thousand heads, and northern ones - only 10-15 thousand heads.
Southern elephant seals are hunted on coastal haulouts, and there are restrictions on fishing for the seasons, the size of the hunted seals at least 3.5 m long and their number. For example, in 1951, 8,000 elephant seals were allowed to be harvested; mined 7877. Fat and skin are obtained from the mined animals.
Class: Mammals
Order: Pinnipeds
Family: True seals
Genus: Elephant seals
Species:Southern Elephant Seal
The southern elephant seal (Mirounga leonina) is an animal of the True seals (Phocidae) family.
The southern elephant seal is the largest carnivore on our planet. Male southern elephant seals weigh an average of 2.2 tons. up to 4t. and can reach up to 5.8 meters in length. The largest copy among the southern elephant seals, reached a length of 6.85 meters and weighed about 5 tons.
Southern elephant seals can stay underwater for over twenty minutes.
The documented record for being underwater was approximately two hours. Max Depth, which can dive southern elephant seals, is more than 1400 meters.
Elephant seals have a long hanging nose resembling a trunk, which is why they are called so.
An elephant spends most of its life, over 80 percent, in the ocean.
http://malpme.ru/samye-krupnye-zhivotnye-na-zemle/
The southern elephant seal lives along the coast of Antarctica and the subarctic islands. Before humans landed on Antarctica, elephant seals lived farther north than they do now. The largest population lives on the island of South Georgia in the South Atlantic Ocean. Also, the southern elephant seal is located on the islands of Kerguelen, Heard, Macquarie and the Valdes Peninsula in Argentina.
When the southern elephant seal is on land, it is found along the coast on smooth sandy beaches or small rocks. They are found on land only during the breeding season and the molting season, which lasts 3 to 5 weeks in spring. The rest of the year is spent at sea.
Dimorphism is observed not only in size. Males have a large vocalization proboscis used to challenge other males. The trunk of the southern elephant seal is slightly smaller than that of their northern relatives, hanging over the mouth by only 10 cm, compared to 30 cm for the northern elephant seal.
Male southern elephant seals reach rookeries a few weeks before females and, through vocalizations, body positions, and fighting, occupy a certain territory. The best and largest territories go to the largest and strongest males. These alpha males become the head of the harem, and with the arrival of women, it can include about 60 females. If in a harem more women, then the females go to the beta males. A man must stay in his territory, protecting it, so he must long time goes without food. Lack of food and aggressive encounters with males, energy consumption during mating with large quantity women lead to physical exhaustion male body. Only males who are in perfect physical condition able to defend their territory for this long time.
If this does not scare off the applicant, then fights take place.
As a prize, the winner takes the territory.
The shedding process involves shedding all the fur that grows back over the next 3 to 5 weeks. Apart from the time spent on land for breeding and molting, the southern elephant seal lives a solitary life in the waters. southern oceans. While in the water, elephant seals rarely collide with each other and thus have no need for communication.
While at sea, the southern elephant seal is able to stay underwater for up to two hours, but most dives last no more than 30 minutes. Surprisingly, they spend 2 to 3 minutes between dives on the surface of the water. They dive to depths of 300 - 800 m.
southern elephant seal and man
In the past, southern elephant seals were hunted for food, skin, and blubber. This activity has been discontinued and now the animal is protected and its prey is produced in limited quantities.
There are only a couple of species of elephant seals, named according to the part of the Earth's hemisphere they occupy. These are truly unique animals, the sex of the newborn offspring of which is determined by the water temperature and general weather conditions.
Description of the sea elephant
Elephant seal fossils date back hundreds of years. The animals got their name because of a small process in the area of the muzzle, outwardly very reminiscent of an elephant's trunk. Although only males “wear” such a distinctive feature. The muzzle of the females is smooth with the usual neat nose. On the nose of both of them there are vibrissae - supersensitive antennae.
It is interesting! Each year, elephant seals spend half of the winter season in the process of molting. At this time, they crawl ashore, their skin swells with many bubbles and, literally, comes off in layers. It looks unpleasant, and the sensations are no more joyful.
The process is painful, causing discomfort to the animal. Before everything is over and his body is covered with new fur, a lot of time will pass, the animal will lose weight, become emaciated and haggard. After the end of the molt, the elephant seals return to the water again to gain fat and replenish their strength for the upcoming meeting with the opposite sex.
Appearance
These are the largest representatives of the seal family. They are geographically divided into two types - southern and northern. The inhabitants of the southern regions are slightly larger in size than the inhabitants of the northern ones. Sexual dimorphism in these animals is extremely pronounced. Males (both southern and northern) are much larger than females. The average mature male weighs about 3000-6000 kg and reaches a length of five meters. The female, on the other hand, hardly reaches 900 kilograms and is about 3 meters tall. There are at least 33 species of pinnipeds, and so elephant seals are the largest of all.
The color of an animal's coat depends on various factors, including the sex of the animal, species, age and season. Depending on them, the coat may have reddish hues, light or dark brown or gray. Basically, the females are slightly darker than the males, their coat is close to the earthy color scheme. Males predominantly wear mouse-colored fur. From afar, flocks of elephants that have come out to bask in the sun resemble plush giants.
The elephant seal has a huge body that looks like an oval shape. The paws of the animal are replaced by flippers, convenient for fast movement in the water. At the ends of the front flippers are webbed fingers with sharp claws, in some cases reaching a length of five centimeters. The elephant seal's legs are too short to move quickly on land. The stride length of an adult multi-ton animal is only 30-35 centimeters, because the hind limbs completely replace the forked tail. The head of the elephant seal is small, relative to the size of the body, smoothly flowing into it. The eyes are dark, flattened oval.
Lifestyle, behavior
On land it's huge marine mammal behaves extremely rudely. However, as soon as the elephant seal touches the water, it turns into an excellent swimmer diver, reaching speeds of up to 10-15 kilometers per hour. These are massive animals leading a predominantly solitary lifestyle in the water. Only once a year they gather in colonies for breeding and molting.
How long does a sea elephant live
Elephant seals live from 20 to 22 years, while the northern elephant seal most often lives only 9 years. At the same time, females live an order of magnitude longer than males. It's all the fault of the multiple injuries received by the male in fights for the championship.
sexual dimorphism
The pronounced differences between the sexes are one of the most striking features of northern elephant seals. Males are not only much larger and heavier than females, but also have a large, elephantine trunk, which they need to fight and demonstrate their superiority to the enemy. Also artificially produced distinguishing feature the male elephant seal is the scars on the neck, chest and shoulders, acquired in the process of endless fights for leadership during breeding periods.
Only the adult male has a large trunk resembling that of an elephant. It is also suitable for making the traditional mating roar. The expansion of such a proboscis allows the elephant seal to amplify the sound of snorts, grunts and loud drum bellows that can be heard for several kilometers. It also functions as a moisture absorbing filter. During the mating season, elephant seals do not leave the territory of the land, so the water conservation feature is quite useful.
Females are an order of magnitude darker than males. They are most often brownish in color with highlights around the neck. Such spots remain from the endless bites of males during the mating process. The size of the male varies between 4-5 meters, females 2-3 meters. The weight of an adult male is from 2 to 3 tons, females barely reach a ton, weighing 600-900 kilograms on average.
Types of elephant seals
There are two certain types elephant seals - northern and southern. Southern elephant seals are simply huge. Unlike most other oceanic mammals (such as whales and dugongs), these animals are not completely aquatic life. They spend about 20% of their lives on land and 80% in the ocean. Only once a year they crawl out onto the shores for molting and performing the function of reproduction.
Range, habitats
Northern elephant seals are found in the waters of Canada and Mexico, while southern elephant seals are found off the coast of New Zealand, South Africa and Argentina. Colonies of these animals crawl out onto the beaches in whole clouds to molt or fight for a pair. This can happen, for example, on any beach from Alaska to Mexico.
Elephant seal diet
Its menu mainly includes cephalopods sea depths. These are squids, octopuses, eels, rays, skates, crustaceans. Also some types of fish, krill and sometimes even penguins.
The males hunt at the bottom, while the females go out to search for food in the open ocean. To determine the location and size of potential food, elephant seals use vibrissae, identifying prey by the slightest fluctuations in the water.
Elephant seals dive great depths. An adult elephant seal can spend two hours underwater, diving to depths of up to two kilometers.. What exactly do elephant seals do during these epic dives, the answer is simple - feed. When dissecting the belly of captured elephant seals, many squids were found. Less often, the menu includes fish or some types of crustaceans.
After breeding, many northern elephant seals travel north to Alaska to replenish their own fat stores, used up during their time on land. The diet of these animals requires deep diving skills. They can dive to depths of more than 1,500 meters, staying under water for about 120 minutes until they resurface. Although most dives at shallower depths last only about 20 minutes. Over 80% of a year's time is spent feeding at sea in order to provide energy for the breeding and molting seasons, in which feeding retreats are not provided.
A huge supply of fat is not the only adaptation mechanism that allows an animal to feel great at such a significant depth. Elephant seals have special sinuses located in abdominal cavity where they can store extra oxygenated blood. This allows you to dive and hold the air for a period of about a couple of hours. They can also store oxygen in the muscles with myoglobin.
Reproduction and offspring
Elephant seals are solitary animals. They come together only for periods of molting and breeding, on land. Every winter they return to their original breeding colonies. Female elephant seals reach sexual maturity at the age of 3 to 6 years, and males at the age of 5 to 6 years. However, this does not mean that a male who has reached this age will begin to participate in reproduction. For this, he is not yet considered strong enough, because he will have to fight for the female. Only by the age of 9-12 will he gain enough mass and strength to be competitive. Only at this age can a male acquire Alpha status, which gives the right to “own a harem”.
It is interesting! Males fight each other using body weight and teeth. While deaths fights are rare - mutual gifts in the form of scars are commonplace. The harem of one Alpha male ranges from 30 to 100 females.
Other males are forced to the outskirts of the colony, sometimes mating with slightly less "quality" females before the alpha male drives them off. Males, despite the distribution of "ladies" that have already taken place, continue to remain on land for the entire period, defending the occupied territories in the struggle. Unfortunately, during such fights, females are often injured and recently born cubs die. After all, during the battle, a huge, six-ton animal rises to the height of its own growth and falls on the enemy with unthinkable force, destroying everything that is in its path.
The annual breeding cycle of the northern elephant seal begins in December. At this time, huge males crawl out onto deserted beaches. A large number of pregnant females will soon follow the males to unite in large groups like harems. Each group of females has its own dominant male. The competition for dominance is extremely intense. Males establish dominance through looks, gestures, all kinds of snorts and grunts, amplifying their volume with the help of their own trunk. Spectacular fights end with a lot of mutilations and injuries left by the fangs of the opponent.
2-5 days after the female stays on land, she gives birth to a baby. After the birth of a baby elephant seal, for some time the mother feeds him with milk. Such food, excreted by the body of the female, is about 12% fat. After a couple of weeks, this number increases to more than 50%, acquiring a liquid jelly-like consistency. For comparison, in cow's milk the proportion of fat is only 3.5%. The female feeds her cub in this way for about 27 more days. At the same time, she does not eat anything, but relies only on her own fat reserves. Shortly before the young are weaned from their mother and set off on their own voyage, the female mates again with the dominant male and returns to the sea.
For a further four to six weeks, the babies diligently swim and dive before leaving the shore where they were born to spend the next six months at sea. Despite the fat reserve that allows them for a long time be without food, the mortality of babies during this period is extremely high. For about another six months, they will walk on a thin line, since it is at this time that about 30% of them will die.
Slightly more than half of mating females do not give birth to a baby. The female's pregnancy lasts about 11 months, after which a litter of one cub is born. Therefore, females arrive at the breeding site already "on demolition", after last year's mating. Then they give birth and get down to business again. Mothers do not eat for a whole month, which is necessary for feeding the baby.
natural enemies
Baby elephant seals are extremely vulnerable. As a result, they are often eaten by other predators, such as or. Also, a large proportion of cubs can die as a result of numerous fights of males for leadership.