The Events

The Animal Series

Rockhopper Penguin

Introduction

The Rockhopper Penguins are part of the order Sphenisciformes. This specific type of bird is incapable of flying. It uses its powerful wings as flippers, for swimming. These carnivorous animals are known to be the most aggressive of all penguins. Right now, they are being protected so that the species does not become extinct.

Classification
Kingdom Animalia
Phylum Chordata
Subphylum Vertebrata
Class Aves
Order Sphenisciformes
Family Spheniscidae

Habitat

The Rockhopper Penguins are located in the southern hemisphere on several islands, such as the Falkand, Macquarie, and Amsterdam Islands. The Falkand Islands used to be the world’s largest Rockhopper Penguin breeding site, with 2,500,000 pairs. These penguins are found in nests and burrows among high grasses and tussocks. Additionally, they live along rocky shorelines.

Feeding/ Food Chain

Rockhopper Penguins, being carnivores, use their orange-red beak to feed on krill, squid, small fish and crustaceans such as shrimp.
These penguins are prey to leopard seals, fur seals, sea lions, and blue sharks. Skuas, Petrels, and Kelp Seagulls prey on the eggs and chicks of Rockhopper penguins.

Social Behaviors
As their name suggests, Rockhopper penguins do not slide on their bellies to get around swiftly like other penguins. Instead, they jump from boulder to boulder on cliffs and along the shoreline in order to avoid obstacles. They communicate a lot, through noises known as ecstatic vocalizations. They are very noisy and often just make sounds to announce their presence and mark their territory. They also bow and wave their flippers to each other.

Often times, the penguins are in groups with other penguins, even when feeding. Although very social, the small Rockhopper penguins are also known to be easily agitated and the most aggressive of the birds. They are not intimidated by larger animals and can fight with their flippers, as well as their beaks. Despite their reputation, Rockhopper penguins are in fact very gentle with their mates.

During mating season, between early spring and late summer, penguins attract their mate from previous years with mating calls and headshakes. The large breeding colonies can grow to hold up to 100,000 nests at one single site. These penguins form a nest by scraping hole in the ground and lining it with dried grasses. Of the two pale-green eggs laid, the first one is smaller and therefore more vulnerable than the second, born 4 days later. After birth, Rockhoppers spend much of their time in the water. They find food and even sleep at sea during their 10 years of life.

Physical Characteristics

Rockhopper penguins are not the typical black and white bird that the word "penguin" is normally related to. They are a part of the family of crested penguins because of the distinctive yellow stripe and crest on the sides of their head above their small red eyes. They are white on the ventral side and blue-black colored on the dorsal side to blend in for protection when floating so that the light hits one side and predators only see the dark, back side. In addition to their feathers that keep out wind and water, they have adapted to the cold environment with both a layer of fat and down.

Their wings are used as fins for swimming, not flying. Their wedge-shaped tails and webbed feet, help them to swim very quickly. Rockhopper penguins loops in and out of the water, a form of swimming called porpoising. As the smallest of the crested penguins and one of the smallest penguins in the world, they may reach up to 55 cm with a weight of 2.7 kg.

Interesting Characteristics

There has been a rapid and substantial decline in population of theses penguins due to commercial fishing that has decreased their food source. They were once hunted for oil, but now all species are protected so that they don't become endangered or even extinct. Climate changes that altered their living environment may have also affected their population. One study by the Royal Society for the Protection of Birds found that the amount of the Northern Rockhopper penguin specifically, has declined by 90% over the past 50 years. This species of penguin is now labeled “Vulnerable” by the International Union for the Conservation of Nature, but not quite endangered yet.

Source: National Geography