Sea elephants are a genus of mammals of the family of true seals, including the largest representatives of the order of predatory mammals. They owe their name to the trunk-like nose in males and large dimensions. Despite the fact that elephant seals belong to real seals, in their behavior and some other characteristics they resemble eared seals more. There are two very similar species - the northern elephant seal inhabiting the west coast of North America and the southern elephant seal inhabiting the Antarctic.
Sea elephants got their name not by chance, these are animals of really gigantic sizes. Body length in males of the southern elephant seal can reach up to 5 m, weight up to 2.5 tons! Females are much smaller and reach “only” 3 m in length. Sea elephants differ from the rest of seals by their overall heavy build and large amounts of subcutaneous fat. The weight of the fat layer can be 30% of the total weight of the animal.
In addition to size, elephant seals have another feature that makes them look like real elephants. Males of these animals have a thickened fleshy growth on the nose, similar to a short trunk. In the marriage period, the trunk is used for decoration, intimidation, and as a resonator, reinforcing a menacing roar.
Sea elephants spend most of their lives underwater, feeding on fish and shellfish. They are able to dive to a depth of about 140 meters, holding their breath for more than two hours. At the same time, the activity of their internal organs slows down, which saves the necessary amount of oxygen. Their natural enemies are the killer whales and white sharks, waiting for the big-nosed seals in the upper layers of the water.
Elephant seals come to shore only in the warm season in order to produce offspring and conceive a new one. For three months, huge colonies fill the coastal zones.
Young three to four year old elephant seals are forced to lead a bachelor lifestyle — they are driven out of the edges of the colony by their more mature eight year old brethren. Considering this state of affairs to be unjust, they from time to time try to break through to “married” females, which leads to new fights.
Species and habitat
Two species of these marine mammals are known - northern and southern elephant seals. The former are found on islands along the west coast of North America. They are slightly smaller than their southern relatives. Males weigh 2.7 tons with a body length of almost 5 m. Their trunk reaches 30 cm, which is much larger than that of the “southerners”.
Southern elephant seals congregate in colonies in sub-Antarctic archipelagoes and islands such as Kerguelen, Macquarie, Hurd, and South Georgia. Separate individuals are found on the coasts of Australia, New Zealand and Antarctica. The weight of the largest males can reach 3.5 tons, and the body length is 6.5 m. The females of both species are half the size of their partners.
On the rookery animals begin to arrive at the beginning of spring. This is the end of August - the first decade of September (in the southern hemisphere, summer begins in December, and winter is in June). First, pregnant females appear on the rocky shores. Males catch up later. Fights immediately begin between them. Sometimes they turn into whole bloody battles, as sea elephants have quite powerful front fangs.
In the end, everything calms down, and each male acquires a harem. It may include 10 females and one hundred. It all depends on the strength and aggression of the male. The birth of babies occurs in September and October. Females crawl to give birth in secluded places. The cub is born alone. The length of his body reaches a meter, and the weight is 25-30 kg.
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 already husbands without the supervision of his mother. When he turns 3 months, he swims with his peers into 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. Female gives birth every year for 10-12 years. These animals live an average of 20 years.
Another enemy is man. In past centuries, he ruthlessly destroyed harmless animals for their fat. With one killed elephant seal received at least 500 kg of valuable product. Nowadays, fishing for these marine animals is prohibited. In this regard, 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.
The presence of elephant seals on real seals today is indisputable, but their position within this taxon is often the subject of debate. King expressed the hypothesis in 1983 that elephant seals are most closely related to the monk seal family, and both genera represent the most ancient forms of true seals. In 1996, Binida-Emodns and Russell could not find evidence of such a close relationship, but confirmed the basic position of elephant seals in the systematics of real seals.
Elephant seal description
The first finds of elephant seal fossils date back a hundred years ago.. The animals received their name because of a small process in the muzzle, which looks very much like an elephant's trunk. Although only males "wear" this distinctive feature. The muzzle of females is smooth with the usual neat nose. On the nose of both those and others are vibrissae - super sensitive antennae.
It is interesting! Each year, elephant seals spend half the winter season in the process of molting. At this time, they crawl out onto the shore, their skin swells up with a multitude of bubbles and, literally, comes down in layers. It looks unpleasant, and the sensations are no more joyful.
The process is painful, causing animal discomfort. Before everything is finished and his body is covered with a new coat, it will take a long time, the animal will lose weight, will become exhausted and emaciated. After the end of the molting, the elephant seals return to the water again in order to pick up fat and replenish their stores of strength for the upcoming meeting with the opposite sex.
On land, this huge marine mammal behaves extremely awkwardly. However, as soon as the sea elephant touches water, it turns into a great diver-swimmer, which develops speeds of up to 10-15 kilometers per hour. These are massive animals, leading in the water mostly solitary lifestyle. Only once a year, they gather in colonies for breeding and molting.
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 elephant trunk, which they need for fights and for demonstrating their superiority to the enemy. Also, the artificially obtained distinctive feature of the male elephant elephants is the scars on the neck, chest and shoulders, acquired in the process of endless fights for leadership during the breeding periods.
Only an adult male has a large trunk resembling an elephant's trunk. It is also suitable for issuing the traditional roar of marriage. The extension of such a proboscis allows the elephant seal to amplify the sound of snorting, grunting and loud drum bellows, which can be heard for several kilometers. It also performs the function of a moisture-absorbing filter. During the mating season, elephant seals do not leave the land, therefore the water saving function is quite useful.
Females much darker than males. They most often have a brownish color with lightened parts around the neck. Such stains from the endless bites of males in the process of mating remain. The size of the male ranges from 4-5 meters, females 2-3 meters. The weight of an adult male is from 2 to 3 tons, the females barely reach tons, weighing 600-900 kilograms on average.
There are two separate species of elephant seals - northern and southern. Southern elephant seals are huge. Unlike most other oceanic mammals (such as whales and dugongs), these animals are not fully aquatic. 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 breeding function.
Northern elephant seals are found in the waters of Canada and Mexico, while the southern ones are located off the coast of New Zealand, South Africa and Argentina. Colonies of these animals creep up on the beaches to molt or fight for a couple. This can happen, for example, on any beach from Alaska to Mexico.
Sea elephant - animal predator. Its menu, mainly, includes cephalopods of the deep sea. These are squids, octopuses, eels, rays, skates, crustaceans. Also some types of fish, krill, and sometimes even penguins.
Males hunt at the bottom, while females set off to search for food in the open ocean. To determine the location and size of potential food, elephant seals use vibrissae, determining prey based on the slightest water fluctuations.
Sea elephants dive to great depths. Adult sea elephant can spend two hours under water, plunging to a depth of two kilometers. What exactly elephant seals do during these epic dives, the answer is simple - they feed. When dissecting the belly of caught elephant seals, a lot of squids were found. Less often, the menu includes fish or some species of crustaceans.
After breeding, many northern elephant seals head north to Alaska to replenish their own fat reserves used during their time on land. The diet of these animals requires deep-sea diving skills. They can dive to a depth of more than 1500 meters, remaining under water until an extraordinary ascent of about 120 minutes. Although most dives at shallower depths last only about 20 minutes. More than 80% of the pastime per year is spent on feeding at sea, in order to provide themselves with energy for the breeding season and molting, in which no retreat for feeding is provided.
A huge store of fat is not the only adaptation mechanism that allows an animal to feel great at such a significant depth. Sea elephants have special sinuses located in the abdominal cavity, where they can store additional amounts of blood enriched with oxygen. This allows you to dive and hold the air for about a couple of hours. They can also store oxygen in muscles with myoglobin.
Population and species status
These animals often became the object of fishing because of their meat, wool and fat.. Both northern and southern species were on the verge of extinction. By the period of 1892 they were considered completely extinct. But fortunately, in 1910, in the vicinity of Guadalupe Island, near lower California, one colony was identified. Closer to our time, several new marine environmental laws were created to protect them, and this gave its results.
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Today, fortunately, they are no longer endangered, although they are often injured and die from becoming entangled in fishing gear, wreckage, and collisions with boats. At the same time, the IUCN organization conferred on elephants the conservation status “causing the least fear of extinction”.
Eating northern elephant seal
Nutrition for the elephant seal is molluscs and fish. From time to time, this predator can attack sharks, in a variety of living in the vast Pacific. True, some species of sharks are so impressive in size that they are dangerous to elephant seals. Nevertheless, sharks are not as scary for them as their main enemy is the killer whale. This black and white predator attacks sea lions, which are located on the shore, near the water. Killer whale is thrown on the beach and bites its teeth into the nearest animal, and then, drags the victim back to the sea.
In the breeding season, males start whole harems.