Description
& Characteristics:
The
Rockhopper penguins are small, aggressive, crested penguins
(genus Eudyptes), so named because of the way they hop from
boulder to boulder when moving around their rocky colonies.
Rockhoppers are a sub-Antarctic species breeding at cool,
southern localities such as Macquarie Island, the Falklands,
Campbell Island, Tristan da Cunha, and the Antipodes. On some
islands the populations have declined substantially and the
species has just been upgraded to 'vulnerable' by the International
Union for the Conservation of Nature. Although there is as
yet no consensus of opinion, three subspecies of Rockhopper
have been recognized.
Rockhoppers have distinctive crest feathers on their heads,
bright orange-red bills and tiny blood red eyes. Males and
females are very similar in appearance, though males are larger.
They are distinguished from the Macaroni
penguin and other members of the crested species by their
smaller size and the thin, vivid yellow tassels which extend
along the sides of the brow but do not meet
between the eyes. The top of the head has spiked black feathers.
Like all penguins, Rockhopper have a big head, a short, thick
neck, a streamlined shape, a short, wedge-shaped tail, and
strong, stiff, flipper-like wings. For camouflage from predators,
their underparts are mostly white, while the upperparts are
blue-black.
Rockhoppers
use their webbed feet and strong powerful flippers for swimming
and pursuit diving after prey. They feed mostly upon lantern
fish, small euphausiid crustaceans (mainly krill), and occasionally
squid. Their exceptional hopping abilities are required to
enter and emerge from the sea and to reach their rocky nesting
sites.
Breeding
during the summer months, mated Rockhopper pairs establish
rocky burrows among tumbled boulders or on scree slopes of
exposed shores. Female Rockhoppers will lay two eggs though
the smaller, first-laid egg is often lost during incubation
and even if retained, does not always hatch. Males and females
take turns guarding and feeding the growing chick which fledges
in March.
Rockhopper
colonies are often relatively small compared with other penguin
species but what they lack in size they make up for in noise.
Fierce competition for nesting materials, mating partners,
and territory all contribute to the cacaphony of sound at
these sites. As well as vocalizing, these birds communicate
by head shaking, head and flipper waving, bowing, gesturing
and preening.
At sea,
Rockhopper penguins are eaten by blue sharks, leopard
seals and fur
seals. On land, eggs and chicks are eaten by many birds,
including skuas,
petrels,
and Kelp gulls.