Why are there no polar bears in Antarctica?

Having become the icon of the ecological impact of human activities – and more particularly of the melting of glaciers – the polar bear is nevertheless absent from Antarctic territory… Why?

The Arctic and the Antarctic: two territories that are actually very different

The Arctic and Antarctica have similar ecosystems in only some respects. If the two poles are home to various species of seals and whales, only the Arctic is home to the largest bear on the planet: the polar bear.

We find polar bears around the polar circle in Alaska, Canada, Greenland (part of Denmark), Norway, Russia and occasionally Iceland. Polar bear fur is specially adapted to temperatures that can drop below minus 22 degrees Fahrenheit (-30 degrees Celsius). They live on ice for most of their lives, feeding on high-fat seals that allow them to conserve energy for long periods between meals.

Antarctica also has ice formed from the sea, cold temperatures, seals, etc. In short, a territory similar to the Arctic. And yet…

Polar bears prefer the north

“Bears are largely a Northern Hemisphere phenomenon”, says Andrew Derocher, professor of biological sciences at the University of Alberta in Canada, who has been studying polar bears for nearly 40 years. Only exception: the bear of the Andes which comes from South America.

A possible geographical explanation

Polar bears are – when you look up from an evolutionary perspective – a relatively young species. They evolved from a common brown bear ancestor around 5 million to 500,000 years ago. But even 5 million years ago, the continents were in positions similar to those of today, so polar bears never had the opportunity to travel from pole to pole. . The closest landmass to Antarctica is the southern tip of South America, which includes Chile and Argentina. To get to Antarctica, polar bears would have to cross the perilous Drake Passage. The region is also known for its mighty storms and rough seasthe cold waters of the south colliding with the warm waters of the north.

Antarctica could not have been inhabited by polar bears because the Antarctic continent was too far from other lands when the species arrived on Earth.