Six species of seals (or pinnipeds!) can be found in Antarctica and the Sub-Antarctic islands; they forage and breed in these areas because there is an abundance of food there!
Breeding species on the ground or in the ice?
The Antarctic Fur Seal and the Southern Elephant Seal breed on land, whereas the Weddell Seal, the Crabeater seal, the Leopard seal, and the Ross seal are ice-breeding species. The Antarctic Fur Seal and the Southern Elephant Seal breed on land, whereas the Weddell Seal, the Crabeater seal, the Leopard seal, and the Ross seal are ice-breeding species.
What is the difference between ear seals and true seals?
They are generally divided into two groups: eared seals (Otaridae) and true seals (Phocaenae) (Phocids). The Antarctic is home to the only eared seal that can be found in the Antarctic region. Because of their characteristics, all of the other five species are considered to be true seals. Eared seals, also known as otarids, have ear flips, which are long front flippers that are used for propulsion and do not have visible claws. They also have hind flippers, which allow them to move quickly on land when they are not swimming. Their primary source of insulation is their fur. True seals, also known as Phocids, have ears, but they do not have flaps! There are visible claws on the front flippers, which are shorter than the back flippers. In water, they propel themselves with their hind flippers, and their blubbers serve as their primary source of insulation.
Despite their extreme latitudes, all six species have developed incredible adaptations that allow them to survive and thrive in their environment. Because of their sensitive “whiskers,” which allow them to detect movement in water and scan the area for prey; their special dentition, which has evolved in response to their specific diet; and their natal pelage and blubber, which are essential for their survival;
Because the air is warmer than the water, they stay in the water by sticking their flippers out of the water. Elephant seals in the southern hemisphere, which breed on land, can become overheated when on land, so they cool themselves down by covering themselves with sand.
Seals have also developed the ability to feed at night. Some species rely on krill, which comes closer to the surface of the water during the night, for up to 95 percent of their nutrition. This type of foraging is referred to as nocturnal foraging.
Dive-adapted seals are excellent divers, and they have developed incredible adaptations to the underwater environment. They do not have facial sinuses (air spaces) like humans, and their middle ear has a complex vascular lining to help it cope with the pressure it is subjected to. Exhaling before diving helps them reduce the amount of air in their lungs, which allows them to store the minimum amount of oxygen necessary to survive. Southern Elephant Seals, for example, have been discovered to be capable of diving for up to two hours and reaching depths of 2,000 meters!
Seals eat a variety of foods. Some species rely on krill as their primary source of nutrition. In the case of others, such as the Southern Elephant seal, fish and squid are on the menu as well. Not only does the leopard seal consume krill, but it also consumes seal pups and penguins!
Species that breed in the ice
Don’t be fooled by the appearance of Crabeater seals! The Crabeaters aren’t serving any crabs this time around. This is the seal that is found in the greatest number of places on the planet. It is estimated that there are approximately 15 million penguins in and around Antarctica. What’s more, guess what? They are a circumpolar species, which means they can be found anywhere on the continental surface. There are special teeth in their mouths that are designed to eat krill.
Weddell seals – The Weddell seal is the most southerly of the seals and does not live in colonies. Orcas prey on them because they are deep divers, diving to depths of up to 800 meters!
Leopard seals are the top predators among the pinnipeds, and they are extremely opportunistic in their hunting. Despite the fact that krill constitutes 50% of their diet, they also eat penguin chicks and seal pups in large quantities.
Ross seals – Due to the fact that they breed on older ice floes and in areas that are inaccessible by ship, these creatures are rarely observed and studied.
Breeders who work on the land
Fur Seals – These are the smallest of the Antarctic seals and the only eared seal that can be found at these latitudes. They also have the longest nursing period of any of the Antarctic seals. They were nearly extinct when they were hunted in the early 1800s, but their numbers have increased dramatically since they have been designated as a protected species!
Southern Elephant Seals are massive creatures with sexual dimorphism: males can weigh up to 4,000 kg while females can weigh up to 900 kg. Southern Elephant Seals are found in the southern hemisphere. They hold the world records for seal diving time (up to 2 hours) and depth (up to more than 2,000 meters).
In addition to losing their fur and skin each year, they become quite vocal during this process! Because mature males gradually develop a large nose, which amplifies the sound of their calls and makes them more attractive to females, they are known as elephant seals.