Rockhopper penguin is a crested penguin known for the way it hops from rock to rock on land. Crested penguins have a crest (display) of bright yellow feathers above the eyes. There are two species (kinds) of rockhopper penguin: the northern and the southern. The northern rockhopper has the larger, more luxurious crest, with yellow and black plumes that may reach 3 inches (8 centimeters) in length.
The southern rockhopper is the smallest of the crested penguins. Adults measure from 18 to 22 inches (46 to 56 centimeters) tall and weigh 5 to 9 pounds (2 to 4 kilograms). Adult northern rockhoppers measure from 22 to 26 inches (56 to 66 centimeters) tall. Females are slightly smaller than males. The head, face, and upper body of both species are black. The throat, belly, underside, and back edge of the flippers are white. Both species have strong, reddish beaks and red eyes. Among rockhopper chicks, the head, neck, and back are dark grayish-brown, but the belly is white.
Southern rockhoppers live on islands near the Antarctic and some temperate islands in the Southern Hemisphere. They once formed huge colonies of around 1 million breeding pairs. But many populations of southern rockhoppers have dropped so much that these penguins are now considered vulnerable to extinction. Northern rockhopper penguins live on small islands in the South Atlantic and South Indian oceans. Rockhoppers are threatened by commercial fishing, destruction of habitat, and pollution. Oil pollution from large ships, such as bulk carriers, kills huge numbers of rockhoppers. Non-native predators, introduced by human activities, also threaten rockhopper populations.
Rockhoppers eat fish, squid, and crustaceans, a group of animals that includes crabs, lobsters, and shrimp. Their diet depends upon their location and the time of year. Fur seals, sea lions, and such birds as skuas, gulls, and giant petrels prey on rockhoppers.
Rockhopper penguins build their nests among the boulders of rocky beaches or among tussock grass. In November or December, the female rockhopper lays two eggs. The first egg is usually much smaller than the second one. The eggs hatch after about 32 to 34 days. Often, only the chick hatched from the large egg survives. Both parents share the duty of looking after the chick. After around 70 days, the chick leaves the nest and enters the sea, able to care for itself.
