Seals are a multispecies family of semi-aquatic predatory mammals. These animals can range in size from 1.17 m (3.8 ft) in length and 45 kg (99 lb) in weight in the ringed seal to 4.9 m (16 ft) and 2400 kg (5300 lb) in the southern elephant seal. All species of seals are characterized by a streamlined body shape and four limbs in the form of flippers.The seal has an elongated body, a small head narrowed in front, a thick fixed neck, the animal has 26-36 teeth. The auricles are absent, instead there are valves that protect the ears from water ingress, the same valves are found in the nostrils of mammals. On the muzzle in the area of the nose there are long mobile whiskers – tactile vibrissae.
Where does the seal live?
The habitat of seals is very wide – all over the world. True, given the marine lifestyle of seals, they all live on the coasts of the seas and oceans. The largest species of these animals live in the cold latitudes of the Arctic and Antarctic, where, thanks to their subcutaneous fat, they tolerate the cold very well, but there are also seals such as, for example, the monk seal that live in the warm Mediterranean. There are also several species of seals, for example, the Baikal seal, which lives in the inland lakes of the continents.
How long do seals live?
The life span of seals depends on whether it is a male or a female, females live longer than males, on average their life is 35 years, males live on average 10 years less – 25 years.
Lifestyle and feeding
Seals are predators, and the main source of their food is various marine animals: fish, mollusks, crayfish, crabs. Large seals such as the leopard seal can eat the penguin. The seal seems to be a clumsy and slow animal, but this impression can only be formed if it is on land, where movement consists in ridiculous body movements from side to side. If necessary, the mammal can reach speeds of up to 25 km/h (15 mph/h) in water and dive to a depth of 600 m. A seal can stay under water for about 10 minutes, due to the fact that there is an air sac on the side under the skin, with the help of which the animal breathes. It’s amazing that animals even sleep in water and underwater.
Seals breed once a year. Most mammals in the family of true seals make permanent pairs. Gray seals and elephant seals are polygamous. At the end of summer, the mating season opens when males compete for the attention of females. Peace-loving animals become fighters capable of even aggression towards the enemy. The process of courtship, mating takes place in sea water, the birth of babies – on ice floes. The gestation of the female lasts
almost a year, from 280 to 350 days. One baby is born, fully developed, sighted, finally formed. The body length of a newborn is about 1 m (3 ft), weight is 20 kg (44 lb). The kid cannot accompany his mother on sea voyages and spends time on a drifting ice floe. The female feeds the baby with fat milk for one month. Then becomes pregnant again. When maternal feeding ends, the grown white seal is not yet ready for independent life. The fat reserves allow the young seal to hold on for a while. The hunger period lasts 9 to 12 weeks while the animal prepares for its first adult voyages. The time of growing up of cubs is the most dangerous for their lives.
Seals are hunted by polar bears. Killer whales are very harmful to seals. This powerful predator easily catches and eats seals. The animal can run away if only there is enough time to reach the shore, but given the killer whale’s power and speed, this is usually quite difficult to do.
Species of seals
Mediterranean monk seal
Previously, these animals were widespread. Their populations were found on all the islands of the Mediterranean Sea, in the Black Sea, in the vastness of the Atlantic Ocean and its islands.
Now the number of Mediterranean monk seals has dropped significantly. They can still be found in the Cabo Blanco beach area in the northeastern Atlantic Ocean, in the Aegean Sea and near the Madeira archipelago. According to the researchers, the total population of the white-bellied seal is less than 700 individuals.
Hawaiian monk seal
This seal species is found primarily in the northwestern Hawaiian Islands, including Laysan, Midway and Lisyansky Island, Kure Atoll and Pearl and Hermes Atoll. Unlike most of their relatives, these animals live in warm subtropical waters.
On land, these seals are in the breeding season. Also, they can often be seen lying on the sandy coast, resting on volcanic rocks or coral reefs.
The main food of the Hawaiian monk seal is fish, crustaceans, eels, cephalopods and other benthic organisms. This seal species was nearly extinct due to large-scale hunting in the 19th century and is still considered critically endangered.
Northern and Southern elephant seal
As the name suggests, the elephant seal is the largest seal species, reaching 21 feet (6.5 m) in length and 7,700 pounds (3500 kg) in weight. Also, a certain property is given to elephants not only by their large size, but also by the presence of a trunk in male elephant seals. Depending on their habitat, elephant seals are divided into two subspecies: the northern elephant seal lives off the coast of North America, and the southern elephant seal lives in Antarctica.
These animals live near Antarctica. Ross seals have long front and rear fins, very short fur, and a rather small head with a wide and short muzzle. After one year of molting, these animals acquire a silvery color on the abdomen and dark grayish-black on the back with brown or red-brick veins protruding from the lower jaw to the chest.
Ross seals can change their fur to a completely brown color throughout the year. They prefer a solitary lifestyle and do not form large colonies. The mating season is at the end of December, after which a year later the female gives birth to one cub.
This is the most widespread type of seal in the world. The total number of its population reaches about 75 million individuals. Such a huge number of crabeater seals in the world is due to the fact that thanks to the sieve-like structure of their teeth, they can feed on Antarctic krill, which is found in abundance in the Southern Ocean.
They live in the vicinity of Antarctica, although they can sometimes swim to the marginal southern shores of New Zealand, Africa, South America and Australia.
Named for its mottled skin and predatory behavior, this species is considered the most dangerous and aggressive of the seals. Leopard seals in particular don’t hesitate to attack smaller seals of other species, but penguins are their favorite treat. In size, the leopard seal is larger than other species of seals, second only to the elephant seal, its body length can reach 13 ft (4 m), and its weight is 1300 lb (600 kg). Inhabits the entire coast of Antarctica.
This type of seal is distinguished by a spindle-shaped body of dark silver-gray color, the lightest in the lower part, and the presence of white, black and gray spots. These animals are excellent swimmers, capable of diving to over 2,000 ft (610 м) and staying underwater for 82 minutes. Weddell seals also have excellent underwater vision and have a protective membrane that protects their eyes from snow and salt water.
The specific name of these seals is associated with the presence of an inflatable hood on the forehead of adult males. Hooded seal live in deep waters in the far north of the Atlantic Ocean.
The body of these seals is covered with silvery or bluish-gray fur with characteristic black spots. Fins have large claws that make it easier to capture prey in the water, but impede fast movement on land.
Hooded seal are distinguished by a solitary lifestyle. They gather in flocks exclusively during the breeding season and during the molting season. The cubs of these seals are distinguished by very fast maturation – already on the fourth day of their life they stop feeding on mother’s milk.
Hooded seal has the shortest lactation period among all mammals on earth. After the mother leaves them, young Hooded seal survive among the ice at the expense of their fat reserves.
Harbor seal (Сommon seal)
This seal species is found in arctic and temperate maritime climates along the coasts of the Northern Hemisphere. It is also considered one of the most common seals in the coastal waters of the Pacific and Atlantic Oceans, Baltic and North Seas. Common seals have a brown, gray or silvery white body color and characteristic V-shaped nostrils.
These animals are found mainly in rocky areas. Coastal cliffs provide them with reliable shelter from predators and harsh weather conditions.
Cubs of common seals can swim and dive already several hours after birth. Their rapid development is facilitated by the very fat milk received from the mother.
This seal species lives on the coast of the North Atlantic. Gray seals hunt fish (mainly benthic species), catching it at a depth of 230 ft (70 m) or more. Their diet also includes wrasse and cod fish, sand eels, lobsters and flounder.
Cubs of gray seals are distinguished by silky snow-white fur and grow quickly due to their mother’s fat milk. These marine animals are protected by law in the US and UK.
Another of the northern seals that lives on the coast of Greenland. They differ from other species of seals in their characteristic color: only they have a silvery-gray wool, a black head, and a black horseshoe-shaped line that stretches along both sides. The harp seal is one of the smallest representatives of seals – its body length is 6 ft (170-180 cm), weight is 260 lb (120-140 kg).
It differs from other seals in the unusual striped color of white and black flowers. Lives in the Bering, Okhotsk and Chukchi seas. In case of danger, they can pretend to be dead.
The bearded seal is a medium-sized pinniped and the largest northern Phocids. These animals live in the White and Barents Sea, in the Mezen Bay. Sea hares feed on capelin, arctic cod and perch.
Seals are sedentary, sometimes migrating due to the harsh habitat.
This seal species lives both in the Arctic and in the subarctic regions, as well as in the Hudson Bay, the Bering and Baltic seas. The ringed seal is the smallest Arctic seal.
It is characterized by a small head, a loose body and a short feline muzzle. The fur of the ringed seal is dark with silver rings on the sides and on the back, and the abdomen is distinguished by a silvery tint. The average body length of this seal species is 1.5 m. Ringed seals spend a considerable time lying on ice floes, and when they melt, they migrate further north in search of denser ice.
The diet of these animals is based on mysids, herring, Arctic cod and shrimps. The main enemies of the ringed seal are Greenland polar sharks, polar bears and arctic foxes.
This type of seal is characterized by a pale coloration of the abdomen and a dark silvery color of the body. The fur is characterized by a pattern of dark spots that are evenly distributed throughout the body. The head of the spotted seal is round with a narrow muzzle, and the fins are narrow and short.
The spotted seal is found in the northern part of the Pacific Ocean and on the far northern edge of the Arctic Ocean. Most of these seals can be seen on the southern edge of the pack ice from winter to early summer, when they move to coastal areas. Although hunting for the Far Eastern seal is permitted, this does not greatly affect the size of its population.
This seal species is the only representative of the pinnipeds family found in freshwater reservoirs. The flexible torpedo-shaped body gives the Baikal seal the glory of an elegant swimmer. Powerful rear fins provide this animal with a high speed of movement in the water.
Adults of the Baikal seal have dense fur of a dark silver-gray shade in the upper part of the body and yellowish-gray – at the bottom. The thick layer of fat provides these animals with good buoyancy and protection from the cold. Baikal seals are found exclusively on Baikal – the oldest and deepest lake in the world.
The Baikal seal is one of the smallest true seals. Adults typically grow to 1.1–1.4 m (3 ft 7 in–4 ft 7 in) in length with a body mass from 63 to 70 kg (139 to 154 lb).
This seal species is endemic to the Caspian Sea. The color of the upper part of the body of the Caspian seal varies from grayish-yellow to dark gray, while the sides and abdomen are distinguished by a lighter gray tint, and on the back there are dark spots of an irregular shape. Cubs of these seals are born with white and longer fur, which sheds three weeks after their birth, and instead the body is covered with dark and short light hairs.
The Caspian seal feeds on sprat and crustaceans. Its main enemies are large eagles and wolves. The females of these seals give birth to cubs after 11 months. The Caspian seal is one of the endangered species and is especially vulnerable due to its narrow distribution range.