With their vast, icy landscapes and long periods of darkness or daylight, the polar regions can appear pretty much the same. But they’re actually worlds apart.

These unique characteristics are reflected in the wildlife living in each place. Some species, like polar bears, evolved to hunt and breed on the ever-shifting ice pack of the Arctic, while other types of closely related species, such as ringed seals and Weddell seals, have adaptations specific to life in the north or south. And one incredible animal—the Arctic tern—lives at both ends of the Earth, thanks to the longest known migration on the planet. (See amazing pictures of animals in the coldest places on Earth.)

Polar misconceptions and myths abound,