Winter Survival: Hibernation in the Arctic vs. Antarctica

Arctic

True hibernation (deep torpor, metabolic suppression) occurs in:

• Arctic ground squirrel
• Arctic fox (some populations)
• Brown bears and polar bears (females denning)

Other species enter winter lethargy (reduced activity, easily roused): Arctic hare, reindeer/caribou.

Active winter residents (lemmings, ptarmigan, wolves) rely on insulation, cached food, and hunting.

Antarctica

No native land mammals exist. The continent's fauna is marine: penguins, seals, whales. They survive via:

• Thick blubber and feathers
• Long migrations to feeding grounds
• Efficient huddling (emperor penguins)

Hibernation is irrelevant in Antarctica; the strategy is marine adaptation and mobility.