In 1936, a Norwegian nature society actually attempted to introduce penguins into the Arctic. The experiment was a complete failure—a preview of the disaster a polar swap would cause.
Introducing polar bears to Antarctica and penguins to the Arctic would trigger two entirely different ecological outcomes: a devastating feast in the south and a rapid extinction in the north. The results come down to how these environments have shaped the evolutionary history of the animals that live there.
Polar Bears in Antarctica
Antarctica is an isolated landmass surrounded by the Southern Ocean, and it completely lacks native terrestrial predators. Because of this, animals like Emperor penguins, Adélie penguins, and Weddell seals have evolved with no instinctual fear of land-based threats. They rest, mate, and raise their young openly on the ice.
If polar bears were introduced to this environment, they would find an essentially defenseless prey base. Polar bears are highly specialized apex predators used to stalking cautious seals across the Arctic ice. In Antarctica, they would simply be able to walk up to massive colonies of penguins and seals. The initial result would be a population boom for the bears as they decimated the native wildlife. Over time, this intense predation would likely cause severe ecological damage, potentially driving certain penguin or seal populations to collapse, which could eventually starve the polar bears once the ecosystem's balance was destroyed.
Penguins in the Arctic
The Arctic, unlike Antarctica, is an ocean surrounded by the connected landmasses of North America, Europe, and Asia. This geographic reality means the region is heavily populated by terrestrial predators, including Arctic foxes, wolves, wolverines, and bears.
Penguins are incredibly agile in the water but awkward and slow on land, where they are forced to spend significant time molting, nesting, and raising their chicks on the ground. If dropped into the Arctic, penguin colonies would be instantly targeted by terrestrial predators. Their eggs and chicks would be relentlessly raided by foxes, while adults would easily fall prey to wolves and bears.
There is historical precedent for this vulnerability. The Great Auk was a flightless, penguin-like bird native to the Northern Hemisphere that was hunted to extinction by humans and predators. Furthermore, as seen in the 1936 experiment where King penguins were introduced to the Lofoten Islands in Norway, the birds simply cannot survive. The last of these introduced penguins disappeared by 1949, entirely unable to establish a foothold in an environment so naturally hostile to flightless, ground-nesting birds.