Life on the ice is rare. This layer of ice which forms during the polar winter in the Arctic, when the temperature of the sea water drops below – 1.8 ° C, constitutes a place which seems very hostile to the development of life. However, some animal species have adapted to live there. We present here six species.
1- the polar bear
How can we not begin our overview of the animals living on the ice floes with the polar bear, emblematic animal of this very special environment? The polar bear has adapted perfectly: thick, white fur provides it with perfect camouflage, black skin absorbs the heat of the sun, small ears limit heat loss, wide paws, covered with hair, are slightly webbed to avoid sinking into the fresh snow. The webbed legs also ensure the efficiency of swimming when it becomes necessary to dive.
Seals are the main food of the polar bear, but they do not disdain the smaller prey, especially in the summer when the sea ice is smaller. They then eat foxes and birds.
2- The ivory seagull
The silhouette of the ivory seagull is close to that of the pigeon. Its plumage is immaculate white but its legs are black. The ivory seagull, also called the white seagull, lives all year round in the inhospitable space that constitutes the ice floe. However, it happens that when the climatic conditions are exceptionally severe, a few individuals fall back to reach the north of the British Isles.
Ivory Gulls can nest in flat terrain or on steep cliffs adjacent to areas of ice. It feeds on the remains of corpses which it cleans with precision, rejecting non-digestible matter such as bones and hair in the form of balls. To find this food, it suffices to closely follow the polar bears that go hunting. She thus reveled in what bears leave behind. She may also be interested in food residues from the droppings of bears, walruses and seals.
3- The emperor penguin
The emperor penguin is a bird measuring around 1.20 m in height as an adult and weighing between 20 and 40 kg. Its back is black and its belly white. Unable to fly, its wings are stiff and flattened. His whole body is in fact perfectly adapted to sea travel.
This bird manages to maintain its body temperature (initially at 39 ° C but can drop by 1.5 ° C), while that of the air can reach -40 ° C. It is its feathers that ensure the role of insulation: every square centimeter of the penguin’s body is covered with 15 stiff, short and lanceolate feathers, thus constituting the densest plumage of all birds. The maintenance of the plumage is vital to guarantee the insulating role and the impermeability of the plumage.
4- the polar fox
The polar fox is a canine which measures about fifty centimeters without the tail. He lives on the ice floes, but also in the tundra. Because of this, its long and thick hairs are only white in winter. In summer, the coat shortens and turns brown. Its pointed muzzle is shorter than that of the red fox. It is able to withstand extreme temperatures of – 70 ° C. It feeds on small animals like the lemming or the arctic hare, also eats fish, eggs and small birds. It can supplement its diet with the corpses of seals and reindeer left by polar bears and wolves.
Seals live a lot in the water: to hunt, move around and even rest. A slender body, a pointed muzzle, the absence of an ear pinna and internal genitalia: in seals, everything is designed to glide as perfectly as possible in the water. When they hoist themselves up on the pack ice, it can be to rest, warm up, give birth and moult.
The quintessential pack ice seal is the hooded seal. Its body is silvery gray with black spots. It owes its name to the nasal appendix that males display and which can swell in the presence of females, but also when it is necessary to intimidate an opponent. He does not appear until he is four years old. A male can exceed 3 meters in length and weigh more than 400 kg. Females are much smaller. The hooded seal’s food consists of mussels, starfish, squid, shrimp, herring and cod. Apart from humans, its main predator is the killer whale.
Unlike seals, walruses swim much shorter. They therefore spend more time resting on the ice of the pack ice. Females also give birth there. It is not uncommon to observe walruses drifting on pieces of iceberg.
They are easily identifiable by their tusks and mustaches. They feed on snails, clams and worms located at the bottom of the water, at shallow depth. Most males weigh between 800 kg and 1,800 tonnes, females weighing only a third at most, and are around 3 meters long.
The skin of the walrus is waterproof. Several centimeters thick (up to 10 cm at the neck in males) and very wrinkled, it is thanks to her that it supports contact with ice. In the end, he fears the heat more than the cold.
The other wonders of the arctic
With these 6 animals, we approached life on the ice. But it is certainly under the sea ice that life is the richest. For example, the zooplankton is very varied: there are jellyfish, including the parasol which can exceed 2 meters in diameter, and many crustaceans.