Rockhopper penguins are a species that belong to the taxonomic Genus of crested penguins Eudyptes, (having crests on their head). They are named for their habit of hopping from rock to rock.
God has gifted these birds with amazing abilities. They may not be able to fly in the air, but they can sure fly under the water. They also know exactly when to start mating, and how to do a mating call. They remember where they nested and return to that exact nest in the midst of 100,000 others, and they lay their eggs. They are able to figure out which eggs to keep depending on its size, and they keep the one that has the best chance for surviving. They know exactly where and when to go for nesting and feeding.
Rockhopper penguins are about 55cm long, and weigh about 2.5 kilograms. They stand on two legs that are set back on their body. They have a short, round bill that is slightly red, and short, stubby legs that are pink. The females tend to be smaller than the males.
They have a waterproof coat that measures a thickness of 2.9 cm. It keeps the water out by keeping a cushion of air underneath the first layer of feathers that seals off the water. The ventral side of their body is colored white, and the other sides of the penguin are colored bluish-black. They have strong, narrow, and stiff wings that act like flippers, and enable them to "fly" under the water. They will also molt their feathers periodically as well. They are the smallest of all crested penguins, and there crest goes from the side of their head near the eyes to the back of their head. Above the crests, on the tops of their heads, they have spiked black feathers. Their eyes are small, and reddish-brown.
Rockhopper chicks don't have a brownish beak when they are born, and they are also born without their yellow crests on each side of the head. They will eventually begin to molt their baby feathers and then get their smoother feathers, instead of the fluff that they were born with. After they have molted, they have reached the "teen years" of penguin maturity. They have what appears to be a yellow eyebrow over each eye, the start of the crest and their beak is then the color of the adult. When they are about four years old, they have reached adult maturity and will have their full-grown crests.
The mating of the rockhopper penguin takes place during the summer. Some of the rockhopper penguins have different mating calls to attract their mate. This is sometimes called ecstatic vocalization. It helps them communicate the intentions of the penguin. Penguins usually reproduce with their same mate for many years.
After the penguins have mated, they create a nest to keep their eggs in. They dig a hole in the ground and surround it with dried grass. Sometimes, they construct their nest behind high grass called tussocks so they can't been seen from below or from the sides. The rockhoppers usually lay an average of two eggs. It is also been known for them to adopt a third egg from another nest. The adopted eggs usually don't survive. During the first period of egg laying, usually only one egg survives. The egg that doesn't survive is usually the smaller of the two, gets eaten by predators, or is kicked out of the nest by the parents. There are some rare occasions where the egg that gets kicked out does mature into a fully grown bird if the egg is not eaten by the predators. The other egg will eventually hatch and be nurtured and cared for by its parents. The male stays at the nest with the baby, and the female goes out and catches fish for food.
Rockhopper penguins are named for their habit of hopping from rock to rock. They also tend to be aggressive with everyone but their mate. They are often preening their mate, which is mainly known as allopreening. They are very protective of their families. They peck at anyone or anything that comes to close, human or animal. They are not intimidated by anything, and they hate to be alone without company. They are very sociable with the other penguins before they mate.
The rockhoppers' main habitat is a group of islands called the Falkland Islands. They are the only species of penguin found so far north. They are also found in places such as Argentina and Chile. They like to nest their colonies near the water on rocky slopes, where they can hop on rocks and be close to fresh water because they are good places to bathe and are filled with fish. They feed on crustaceans, and dive for them in groups. They also feed on squid, krill, and small fish. They can dive as far as 100 meters below the surface, but they tend to prefer the shallow waters. Penguins have three modes of transportation; waddling, sliding on their stomachs, and swimming in the ocean. Penguins sliding on their stomachs have also been called "tobogganing." They use tobogganing to get themselves to exactly where they want to go.
The Rockhoppers' nesting ground contains usually up to 100,000 nests, and sometimes the penguins share nesting grounds with either albatross or cormorants. These birds don't tend to interfere with the habitat of the penguins. They return every year to the same spot for breeding, and use the same nest most of the time. If the nest is in any kind of disrepair, then they usually repair it instead of reconstructing the entire thing. They begin their breeding in October, and they usually travel in two different groups; a male group and a female group. The males get there a few days before the females and get everything ready for them to lay their eggs. After the eggs have hatched and the babies have molted, they leave for the open sea at about 65 to 72 days old.
The rockhoppers' seventeen species are all legally protected now, but they were once vulnerable to hunting and egg collecting. They are now protected by the Antarctic Treaty of 1959, which makes it illegal to harm or interfere with any of the penguins, their eggs, or their lifestyle. Any penguin specimen that is collected must have an approved permit from Scientific Committee for Antarctic Research, or SCAR. They are still vulnerable things such as oil spills, habitat destruction, overfishing, pollution, and human encroachment on nesting areas. It is said that because of pollution, the population of Rockhoppers has gone down thirty percent in the past thirty years. It is for that reason that the IUCN has officially declared them vulnerable. Also, because of overfishing in some areas, the original population of 2.5 million breading pairs has shrunk down to only 300,000 breeding pairs. If this kind of decrease in population continues, they will very soon officially be listed as an endangered species.
- Eudyptes chrysocome rockhopper penguin Devon Phelan, Animal Diversity Web, November 17, 2008.
- PENGUINS AROUND THE WORLD Pete and Barb, Loogootee Elementary West, 03/20/2008.
- Rockhopper Penguin Judith Coats and Debbie Nuzzolo, SeaWorld Education Department, Thursday, November 20, 2008.
- Eudyptes crestatus, Rockhopper Penguin Dave Houston, MarineBio.org., November 30, 2008