This is despite penguins spending 75% of their lives at sea.

Although penguins spend 75% of their lives at sea, they must come to shore every year to reproduce and to molt their feathers. They do this in a variety of places, from the temporary ice sheets of the Antarctic to the beaches of South Africa and Namibia, to the rocky shores of subantarctic islands, to the craggy lava surfaces in the Galapagos. Different penguin species have different nesting practices. Some dig burrows into dirt, sand, or dried guano; some nest in tussock grasses; some build nests out of small rocks, sticks, and bones; while others don't build any nests at all. Although most penguins lay a clutch of two eggs, the two largest species, the King and the Emperor, lay a single egg that they incubate on top of their feet for approximately two months.