premise: They are unable to fly in the true sense but the many species of penguin are all very adept swimmers. They literally fly underwater using their wings as flippers and their feet and tails to steer as they hunt fish and squid, which form the bulk of their diet. This extraordinary family of birds feed in the cold waters of the southern oceans (they are only found in the wild in the southern hemisphere). Their bodies are highly adapted both for their aquatic life and for the cold. Their feathers are short and dense to provide insulation and a highly waterproof layer. Their bones are not hollow like most birds but solid, making them stronger and less buoyant, helping them dive deep down to their prey. Like all birds they lay eggs and most species build nests, but some that live on sheet ice in the Antarctic, where there is no nest-building material, incubate their single egg on the top of their feet.
hypothesis: It can be inferred from the passage that you have to go to the southern hemisphere if you wish to see penguins in the wild.