Rockhoppers stand out from the basic black-and-white penguin species with touches of hot color: red eyes, orange beaks and long chrome yellow crest feathers like wild eyebrows. During mating displays, the birds shake their heads rapidly to make the long yellow plumes whirl. Rockhoppers are fiercely territorial and given to noisy displays too. A breeding colony can be heard from miles away—not to mention through the inch-thick glass of Shedd’s penguin habitat.
Using available materials, male rockhoppers carefully select and arrange small rocks in a circle to keep his mate's eggs from rolling away. A nice nest will attract a female or reinforce an existing pair bond. Hauling the rocks one by one in his beak, a male is not above stealing better-looking stones from his neighbors in the breeding colony. Rockhoppers return to the same nest year after year. Pairs usually raise only one chick, taking turns with incubating, brooding and feeding.