Many millions of years ago, the continents had a completely different appearance: they represented a single whole – the continent of Pangea. This allowed the ancient species to spread freely in a single space. But over time, the giant land split and oceans formed between the future continents. It was then that the animals were bred in different parts of the planet.
The ancestors of polar bears were preserved in the Northern Hemisphere: in the territories that later formed Eurasia and North America. And the ancient relatives of penguins remained to inhabit the southern edge of the globe, where Antarctica subsequently arose. From that moment on, their evolutionary paths diverged.
It turned out to be impossible for these species to overcome the vast expanses of water and the change of climatic zones. Therefore, polar bears gradually gained a foothold in the Arctic, and penguins in the southern mainland and island territories, developing their own survival strategies in polar conditions.
The habitat of penguins
These birds have fully adapted to life in the Southern Hemisphere. Most species live on the coasts of Antarctica and nearby islands: South Shetland, Falkland Islands, South Georgia. Some colonies are found much further north, up to tropical latitudes, for example, on the Galapagos Islands.
At the same time, it must be remembered that the main condition for the existence of penguins is access to the ocean, rich in fish and krill. These birds swim and dive well, and their colonies are usually located on rocky shores or icy plateaus. Penguins do not need land for hunting: their whole life is connected with the sea.
The ancestors of penguins evolved in the Southern Hemisphere, and they did not have the opportunity to cross the equator. In addition, competing groups of seabirds and mammals already existed in the northern latitudes, which occupied similar ecological niches.
It is very cold in Antarctica in winter, and the winds reach hurricane force. Nevertheless, it is in such conditions that the largest and hardiest representatives of the family live: emperor penguins and Adelie penguins.
Their ability to survive is based on a whole system of physiological and behavioral adaptations:
dense, multi-layered plumage that retains air and heat.;
⦁ a powerful layer of subcutaneous fat that protects against icy water and winds;
⦁ Special feather structure with water -repellent properties;
The vessels in the extremities are positioned to warm the returning blood.;
The ability to gather in dense colonies to conserve heat at the expense of neighbors;
Reducing activity in severe frosts and using “economical” body postures.
The picture is complemented by unique breeding strategies: emperor penguins hatch their eggs precisely at the height of the Antarctic winter, when competition for territory is minimal. Antarctic waters are rich in plankton, krill and fish, which forms an ideal food base.
Penguins in the Arctic would not be able to survive for several reasons:
Lack of a suitable food supply: the basis of their diet (krill) lives in the Southern Ocean;
High competition: these are pinnipeds and predators (polar bears), against which birds have no defense mechanisms.;
Unstable breeding conditions: in the Arctic, ice is prone to melting, and penguins have a life cycle closely linked to stable ice platforms.
Therefore, evolution has assigned them to Antarctica, and penguins have no chance of survival in the Arctic.
And where do polar bears live?
Polar bears live only in the Arctic – on the drifting ice of the Arctic Ocean, the coasts of North America, Europe and Asia. Their distribution range extends from Canada and Greenland to Chukotka and the Svalbard Archipelago.
Sea ice is vital for these animals: it is from its surface that they hunt seals, which form the basis of their diet. When the ice retreats in summer, the bears are forced to migrate to land, where they find only a limited amount of food. In summer, they lose up to half their weight, experiencing a lack of food supply.
The Arctic creates ideal conditions for the main predator of the North:
The presence of extensive ice fields where seals live;
Long periods of the polar day, making hunting easier;
Low competition and lack of terrestrial predators of comparable size.
Evolutionarily, these predators are associated with northern latitudes. Modern genetic studies show that they descended from brown bear populations that adapted to the Arctic environment about 500,000 years ago.
Polar bears simply will not survive in Antarctica: firstly, Antarctica is too far from the ancestral range, and secondly, there is no suitable food supply, since seals of the Southern Ocean lead a different way of life, and it is much more difficult to get them on land.
Why can’t penguins meet a polar bear in nature?
The separation of the Arctic and Antarctic millions of years ago determined the fate of animals. The barrier of the equator has become insurmountable: neither the ancestors of polar bears nor penguins were able to migrate to the opposite pole.
Climate and ecosystems also play a key role. There are no terrestrial predators in Antarctica, so these birds were able to maintain colonies on land. If bears appeared here, the birds would be endangered. The Arctic was originally a territory for polar bears, and there simply would not be a safe space for penguins here.
Both polar bears and penguins are indicator species: their numbers reflect the state of polar ecosystems. The reduction of Arctic ice due to climate change is leading to a sharp decline in bear populations. And in Antarctica, melting glaciers and declining krill stocks are threatening penguin colonies.
Separated by the history of evolution, geography and climate, these animals have perfectly adapted to the conditions of their habitat. The Arctic has become home to a majestic predator, and Antarctica is the kingdom of persistent and amazing birds. Yes, penguins and polar bears live on opposite sides of the planet, but their meeting is nevertheless possible! … Yes, but only at the zoo.
The fate of these animals is closely linked to global climate change and requires international protection. The preservation of polar ecosystems is the task of all mankind. After all, by protecting polar bears and penguins, we are helping to maintain the balance of the planet and its unique natural heritage.
Olga Pastukhova
