Although penguins are able to swim long distances, they are predominately shore birds and thus do not venture far into the ocean. They have easy access to prey, while nearby predators prevent them venturing too far from their habitat. In the North Pole, predators such as polar bears and arctic foxes would limit their survival. In addition, migrating through warmer waters to reach the northern hemisphere is almost impossible for penguins and could prove fatal.
As they are flightless, the penguins’ range is small unlike many other species of birds, and as such they have remained in roughly the same area, mostly around the South Pole, for 40 million years. Some have been found as far north as the equator, but for most part they have no need to leave their home at South Pole.