Out of the 18 species of penguins, there are 6 species of Rockhopper penguins, all of which are characterized by a yellow crest on each side of their head. The Rockhopper penguin has a very large black head. Its plumage is black on its back and white on its belly.
Environment and behavior
The rockhopper penguin was named after the way it moves. It doesn’t walk, but hops! It is a gregarious bird. They live in big colonies that they share with other species of marine birds. Every October, the males look for a place to nest. They build their nests at the tops of cliffs. Those nests are simple holes surrounded by small pebbles, twigs and feathers. Once the nest is ready, the female joins the male. The couple can remain united for years and return to the same nesting place each season, but if a new female arrives first, the male will mate with her. After mating, a first small egg (alpha) will be laid in November or December. Four or five days later, a second larger egg (beta) will follow. Incubation lasts 32 to 34 days. The male and female take turns sitting on the eggs every 10 to 15 days. Penguins sit on the beta egg longer than on the alpha egg, usually causing development to terminate in the alpha. The chick’s head and back are covered with grey-brown down, while its belly is covered with white down. The parents take care of the beta chick for 25 days. They then go out to sea for food. Meanwhile, the chicks gather in nurseries. In February, after 65 to 75 days of rearing, the chicks molt and take their independence by heading out to sea. Young penguins are recognizable by their small size and their shorter, paler yellow crests. Adult molting takes place in April, after rearing their young. It lasts one to one and a half months, during which they will not go into the water to feed.
Blue sharks, fur seals and sea leopards attack the adults. Skuas, giant petrels and seagulls attack the eggs and chicks.
At some sites, the population has decreased by 30% over the last 30 years. There are multiple reasons for this decline, like intensive fishing and disease. The presence of humans has also proven to be a source of nuisances, by reducing the amount of living space and introducing foreign animal species such as rats and cats.