Adelie Penguin | The Adelie penguin is the smallest and most widely distributed species of penguin in the Southern Ocean and is one of only two species of penguin found on the Antarctic mainland (the other being the much larger Emperor penguin).
The Adelie penguin was named in 1840 by French explorer Jules Dumont
d'Urville who named the penguin for his wife, Adélie. Adelie penguins
have adapted well to life in the Antarctic as these migratory birds
winter in the northern pack-ice before returning south to the Antarctic
coast for the warmer summer months.
The Adelie penguin is one of the most easily identifiable penguin species with a blue-black back
and completely white chest and belly. The head and beak of the Adelie
penguin are both black, with a distinctive white ring around each eye.
The strong, pink feet of the Adelie penguin are tough and bumpy with
nails that not only aid the Adelie penguin in climbing the rocky cliffs
to reach its nesting grounds, but also help to push them along when they
are sliding (rowing) along the ice. Adelie penguins also use their
webbed feet along with their small flippers to propel them along when
swimming in the cold waters.
The Adelie penguin is one of the southern-most birds in
the world as it is found along the Antarctic coastline and on the
islands close to it. During the winter months, the Adelie penguins migrate north
where they inhabit large platforms of ice and have better access to
food. During the warmer summer months, the Adelie penguins return south
where they head for the coastal beaches in search of ice-free ground on
the rocky slopes where they can build their nests. More than half a
million Adelie penguins have formed one of the largest animal colonies in the world on Ross Island, an island formed by the activities of four monstrous volcanoes in the Ross Sea.
Like all species of penguin, the Adelie penguin is a highly sociable animal,
gathering in large groups known as colonies, which often number
thousands of penguin individuals. Although Adelie penguins are not known
to be terribly territorial, it is not uncommon for adults to become
aggressive over nesting sites, and have even been known to steal rocks
from the nests of their neighbours. Adelie penguins are also known to
hunt in groups as it is thought to reduce the risk of
being eaten by hungry predators. Adelie penguins are constantly
interacting with one another, with body language and specific eye
movements thought to be the most common forms of communication.
Adelie penguins return to their
breeding grounds during the Antarctic summer months of November and
December. Their soft feet are well designed for walking on land making
the trek to it's nesting ground much easier as the penguin fasts during
this time. Adelie penguin pairs mate for life in large colonies, with
females laying two eggs a couple of days apart into a nest built from
rocks. Both the male and female take it in turns to incubate their eggs
while the other goes off to feed, for up to 10 days at a time. The
Adelie penguin chicks have an egg-tooth which is a bump on the top of their beaks, which helps them to break out of the egg. Once hatched, the parents
still take it in turns to look after their young while the other goes
off to gather food. After about a month, the chicks congregate in groups
called crèches and are able to fend for themselves at sea when they are between 2 and 3 months old.
Adelie penguins are strong and
capable swimmers, obtaining all of their food from the sea. These
penguins primarily feed on krill which are found
throughout the Antarctic ocean, as well as molluscs, squid and small
fish. The record of fossilised eggshell accumulated in the Adelie
penguin colonies over the last 38,000 years reveals a sudden change from
a fish-based diet to krill that started two hundred years ago. This is
thought to be due to the decline of the Antarctic Fur Seal in the late
1700s and Baleen whales in the twentieth century. The reduction of
competition from these predators has resulted in there being an
abundance of krill, which the Adelie penguins are now able to exploit as
an easier source of food.
Adult Adelie penguins have no
land based predators due to the uncompromising conditions that they
inhabit. In the water however, the biggest threat to the Adelie penguin
is the leopard seal, which is one of the southern-most species of seal
and a dominant predator in the Southern Ocean. These penguins have
learnt to avoid these predators by swimming in large groups and not
walking on thin ice. The killer whale is the other main predator of the
Adelie penguin, although they normally hunt larger species of penguin
further north. South Polar Skuas are known to prey on the Adelie
penguin's eggs if left unguarded, along with chicks that have strayed
from a group.
Adelie penguins inhabit one of
the coldest environments on Earth and so have a thick layer of fat under
their skin helping to keep them warm. Their feathers help to insulate
them and provide a waterproof layer for extra protection. The Adelie
penguin is a highly efficient hunter and is able to eat up to 2kg of
food per day, with a breeding colony thought to consume around 9,000
tonnes of food over 24 hours. The flippers of the Adelie penguin make
them fantastic at swimming and they can dive to depths of 175 meters in
search of food. Adelie penguins do not have teeth as such but instead
have tooth-shaped barbs on their tongue and on the roof of their mouths.
These barbs do not exist for chewing but instead assist the penguin to
swallow slippery prey.
A visit to the Adelie penguin colonies has long since been on the programme for tourists
to the Antarctic, who marvel at the vast numbers of them nesting on the
beaches and hunting in the surrounding waters. This has meant that Adelie penguins
are one of the most well-known of all penguin species today. Early
explorers however, also hunted the penguins both for their meat and
their eggs in order to survive in such uncompromising conditions.
Despite having been confined to living on coastal Antarctica, Adelie penguins
are one of the most common and widespread penguins in the southern
hemisphere. With more than 2.5 million breeding pairs found throughout
southern Antarctica, the Adelie penguin has adapted well to it's
polar habitat. Scientists have also been known to use Adelie penguin
nesting patterns as indicators of climate change, noticing that they are
able to nest on beaches that were previously covered in ice. The Adelie
penguin is listed as Least Concern.
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