Do polar bears and Antarctic penguins hibernate?

There is no colder place than the Antarctic and the Arctic. In these two places live the adorable penguins and polar bears. So do these two animals hibernate? According to down insulation expert Xiao Jianfei, the king of the Arctic Ocean, the polar bear, does not need to hibernate. Bears elsewhere in the world all have the habit of hibernating, called “crouching in the den” in the northeast, relying on burning up the fat stored in their bodies, they can sleep comfortably for several months. But polar bears do not hibernate; they only tuck in their heads and sleep for a few hours when the weather is at its worst. The thick fur on their bodies and the almost equally thick layer of fat inside play an excellent insulating role, and no matter how the snow flies and the storm rages, they can sleep soundly regardless. Penguins do not hibernate either, but they huddle together to walk in order to keep warm.

Appendix: The polar bear is the largest land carnivore in the world, also known as the white bear, and is endearingly clumsy-cute. Its skin is black, and because the fur is transparent it usually appears white, though there are also colors such as yellow. It is huge in size and fierce.

The polar bear's eyesight and hearing are comparable to humans', but their sense of smell is extremely keen, 7 times that of dogs; at a run their top speed can reach 60km/h, 1.5 times that of the world 100-meter champion. Due to the rise in global temperatures, the Arctic floating ice has gradually begun to melt, and the polar bear's former homeland has already suffered a certain degree of damage; before long it may well go extinct and needs humanity's protection.

Polar bears mate in March and April, but the fertilized egg is stored in the fallopian tube and does not develop until autumn, when it enters the uterus and begins to grow, with birth at the end of the year. The cub weighs only a few hundred grams, equivalent to one thousandth of its mother's body weight. But after birth it develops very quickly; its mother's milk has a fat content of over 30%, unmatched by any other carnivore. The cub spends more than 1 year living with its mother bear, learning to hunt and to survive in the harsh Arctic environment, and then begins to live independently. Males generally leave the mother bear earlier than females.

Appendix 2: Penguins comprise 18 independent species in total. The largest species is the emperor penguin, averaging about 1.1 m tall and weighing over 35 kg. The smallest penguin species is the little blue penguin (also known as the fairy penguin), standing 40 cm tall and weighing 1 kg. They have their own unique structure; penguin feather density is three to four times greater than that of birds of the same body size, and the function of these feathers is to regulate body temperature. Although penguin feet are basically similar to those of other flying birds, their bones are hard, and their feet are relatively short and flat. This feature, combined with short wings like two oars, allows penguins to “fly” underwater. Although the Antarctic is bitterly cold, after tens of millions of years of tempering by blizzards, the penguin's whole body of feathers has become overlapping, tightly packed scale-like forms. This special feather coat not only makes it hard for seawater to soak through, but even at temperatures nearly 100 degrees Celsius below zero, it is impossible to break through its insulation line of defense. The Antarctic has much land and wide sea surface, and the abundant marine plankton has become a plentiful food source for penguins.