Adélie penguin facts for kids
Quick facts for kids Adélie penguin |
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| An Adélie penguin | |
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Pygoscelis
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P. adeliae
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| Pygoscelis adeliae (Hombron and Jacquinot, 1841)
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The Adélie penguin (Pygoscelis adeliae) is a Antarctic penguin that has a black head and back with a white chest and belly, and a white ring around each of their eyes. It is named after Adélie Land, in turn named for Adèle Dumont d'Urville, who was married to French explorer Jules Dumont d'Urville, who first discovered this penguin in 1840. Adélie penguins obtain their food by both predation and foraging, with a diet of mainly krill and fish. There are about 2.5 million Adélie penguins in the Southern Ocean around Antarctica. Adélie penguins travel the furthest to breed because they build their nests from stones and need to find stones. Adélies come ashore to breed in the summer. In the winter, they live on ice that floats off the Antarctic shore.
Contents
Taxonomy and systematics
The first Adélie penguin specimens were collected by crew members of French explorer Jules Dumont d'Urville on his expedition to Antarctica in the late 1830s and early 1840s. Jacques Bernard Hombron and Honoré Jacquinot, two French surgeons who doubled as naturalists on the journey, described the bird for science in 1841, giving it the scientific name Catarrhactes adeliæ. They used specimens collected from an area of the continent which had been named "terre Adélie", French for Adélie Land, itself named for Dumont d'Urville's wife, Adèle. The bird was later placed in several other genera, including Eudyptes, Pygoscelis and the now-defunct genus Dasyrhamphus, and was also later inadvertently redescribed as Pygoscelis brevirostris.
The Adélie penguin is one of three species now assigned to the genus Pygoscelis. DNA evidence suggests the Pygoscelis lineage diverged from that of other penguin species some 38 million years ago, roughly 2 million years after the ancestors of the genus Aptenodytes diverged. Adélie penguins evolved about 19 million years ago, branching from the ancestor of the other two members of the genus (chinstrap and gentoo penguins), both of which evolved some 5 million years later. Although it has no identifiable subspecies, the Adélie penguin has two distinct genetic lineages: one found primarily in the Ross Sea, and the other widespread throughout the Antarctic.
The genus name Pygoscelis is a compound word, composed of the Ancient Greek words pugē, meaning "rump", and skelos, meaning "leg". The members of this genus are often called "brush-tailed penguins", a reference to their long, stiff tail feathers. The birds regularly use their tails for support, and the stiff feathers sweep the ground as the penguins walk. The specific name adeliae indicates the location from which the type specimen was collected.
Description
Adélie penguins are the smallest penguins in Antarctica. They weigh only about 8.5 pounds (3.9 kg), or the weight of a typical house cat. They are about 28 inches tall (2.3 ft; 71 cm). Although the sexes look the same, females have shorter wings and beaks, and weigh significantly less. The adult is black on the head, throat and upperparts, with snowy white underparts. It has a conspicuous white eye ring around a black iris. The beak is largely covered with black feathers, leaving only the tip exposed; this is primarily black, though it can show indistinct reddish-brown markings. The upper surface of the wing is black with a white trailing edge, while the underside is white with a narrow black leading edge and a small black tip. The legs and feet, which are mostly unfeathered, are pinkish.
Upon hatching, the chick is fully covered in down feathers. This coat of feathers is typically silvery-grey (darker on the head), though some birds are much darker overall. Within 10 days, the chick moults into another set of down feathers, this time all dark smoky-grey. Once they have moulted a third time, 7–9 weeks after hatching, the immature birds are similar to adults in appearance, though they tend to be smaller with a bluer tinge to their upperparts and white (rather than black) chins and throats. They lack the full white eye ring of the adult until they are at least a year old.
Similar species
The adult Adélie penguin is unlikely to be confused with any other species, but the white-throated immature bird can resemble the chinstrap penguin. However, the black on its face extends below its eyes, and it lacks a black line under the throat (the "chinstrap") that the chinstrap penguin has. In addition, the bill of the chinstrap penguin is longer, and lacks the feathering that covers most of the bill of the Adélie penguin.
Distribution and habitat
The Adélie penguin is a truly Antarctic creature – one of only four penguin species to nest on the continent itself. Breeding colonies are scattered along Antarctica's coasts and on a number of sub-Antarctic islands, including those in the South Orkneys, the South Shetlands, the South Sandwich Islands, the Balleny Islands, Scott Island and South Georgia. The penguins are much less common north of the 60th parallel south, but have occurred as vagrants in Australia, New Zealand and southern South America. During the breeding season, they need bare, rocky ground on which to build their nests. They will not nest on ice, and preferentially choose areas where wind or the angle of the sun (or both) helps to keep snow drifts from accumulating. At the start of the breeding seasons, colony sites may be up to 100 km (62 mi) from open water, though the distance decreases as summer progresses and the pack ice breaks up.
Once they have finished breeding, adult Adélie penguins typically move to ice floes or ice shelves to moult, though some remain onshore. During the winter, the birds remain in the pack ice zone, with most moving north to reach areas where there is visible light for at least part of the day – thus north of roughly 73°S. While some remain near their breeding colonies, others may move hundreds or thousands of kilometres away. As long as there are breaks in the pack ice, they can survive hundreds of kilometres south of open water, and birds are known to forage in winter in areas with up to 80% pack ice cover.
Behaviour and ecology
Apsley Cherry-Garrard, a survivor of Robert Falcon Scott's ill-fated British Antarctic Expedition of 1910, documented details of penguin behaviour in his book The Worst Journey in the World. "They are extraordinarily like children, these little people of the Antarctic world, either like children or like old men, full of their own importance..." George Murray Levick, a Royal Navy surgeon-lieutenant and scientist who also accompanied Scott, commented on displays of selfishness among the penguins during his surveying in the Antarctic: "At the place where they most often went in [the water], a long terrace of ice about six feet in height ran for some hundreds of yards along the edge of the water, and here, just as on the sea-ice, crowds would stand near the brink. When they had succeeded in pushing one of their number over, all would crane their necks over the edge, and when they saw the pioneer safe in the water, the rest followed."
One writer observed how the penguin's curiosity could also endanger them, which Scott found a particular nuisance:
The great trouble with [the dog teams] has been due to the fatuous conduct of the penguins. Groups of these have been constantly leaping onto our [ice] floe. From the moment of landing on their feet their whole attitude expressed devouring curiosity and a pig-headed disregard for their own safety. They waddle forward, poking their heads to and fro in their usually absurd way, in spite of a string of howling dogs straining to get at them. "Hulloa!" they seem to say, "here's a game – what do all you ridiculous things want?" And they come a few steps nearer. The dogs make a rush as far as their harness or leashes allow. The penguins are not daunted in the least, but their ruffs go up and they squawk with semblance of anger.… Then the final fatal steps forward are taken and they come within reach. There is a spring, a squawk, a horrid red patch on the snow, and the incident is closed.
Others on the mission to the South Pole were more receptive of this element of the Adélies' curiosity. Cherry-Garrard writes:
Meares and Dimitri exercised the dog-teams out upon the larger floes when we were held up for any length of time. One day, a team was tethered by the side of the ship, and a penguin sighted them and hurried from afar off. The dogs became frantic with excitement as he neared them: he supposed it was a greeting, and the louder they barked and the more they strained at their ropes, the faster he bustled to meet them. He was extremely angry with a man who went and saved him from a very sudden end, clinging to his trousers with his beak, and furiously beating his shins with his flippers. It was not an uncommon sight to see a little Adélie penguin standing within a few inches of the nose of a dog which was almost frantic with desire and passion.
Cherry-Garrard held the birds in great regard. "Whatever a penguin does has individuality, and he lays bare his whole life for all to see. He cannot fly away. And because he is quaint in all that he does, but still more because he is fighting against bigger odds than any other bird, and fighting always with the most gallant pluck, he comes to be considered as something apart from the ordinary bird..."
Despite their size, Adélie penguins are known for their bold and boisterous personality, and will challenge other animals, including predators far larger than them. In footage shot for the 2018 BBC Earth documentary Spy in the Snow, the boisterous behaviour of Adélie penguins was made especially apparent when an individual arrived to chase off a Southern giant petrel (Macronectes giganteus) that had landed to threaten a group of emperor penguin chicks, in spite of the species difference between them.
Adélie penguins usually swim at around 5 miles per hour (8.0 km/h). They are able to leap some 3 metres (10 ft) out of the water to land on rocks or ice.
Food and feeding
The Adélie penguin is known to feed mainly on Antarctic krill, ice krill, Antarctic silverfish, sea krill and glacial squid (diet varies depending on geographic location) during the chick-rearing season. The stable isotope record of fossil eggshell accumulated in colonies over the last 38,000 years reveals a sudden change from a fish-based diet to krill that began around 200 years ago. This is most likely due to the decline of the Antarctic fur seal since the late 18th century and baleen whales during the early 20th century. The reduction of competition from these predators has resulted in a surplus of krill, which the penguins now exploit as an easier source of food.
Jellyfish including species in the genera Chrysaora and Cyanea were found to be actively sought-out food items, while they previously had been thought to be only accidentally ingested. Similar preferences were found in the little penguin, yellow-eyed penguin and Magellanic penguin.
Migration
Adélie penguins living in the Ross Sea region in Antarctica migrate an average of about 13,000 kilometres (8,100 mi) each year as they follow the sun from their breeding colonies to winter foraging grounds and back again. During the winter, the sun does not rise south of the Antarctic Circle, but sea ice grows during the winter months and increases for hundreds of miles from the shoreline, and into more northern latitudes, all around Antarctica. As long as the penguins live at the edge of the fast ice, they will see sunlight. As the ice recedes in the spring, the penguins remain on the edge of it, until once again, they are on the shoreline during a sunnier season. The longest treks have been recorded at 17,600 kilometres (10,900 mi).
Threats
Adult Adélie penguins are regularly preyed upon by leopard seals. South polar skuas, in particular and Giant petrels kill many chicks and eat eggs as well. Giant petrels and orcas will occasionally kill adult Adelie penguins. Kelp gulls and snowy sheathbills also prey on chicks and eggs.
Status
Because of its very large and increasing population (estimated at more than 10 million mature individuals in 2020), and its unfragmented habitat, the Adélie penguin is considered by the International Union for Conservation of Nature to be a species of least concern.
Chicks and eggs
Adélie parents take turns keeping their chicks warm and fed. While one watches the nest, the other goes into the ocean to catch krill. The penguins carry the krill back to the nest in their stomachs. Then they regurgitate it to feed their chicks.
Most Adélie penguins incubate two eggs at a time. The little chicks hatch out at about the same time. One is usually stronger than the other and has a better chance of surviving.
When first born, the chicks are kept warm by their parents. But after two or three weeks, they grow a thick, woolly gray down. Then they join other chicks in creches, or nursery groups.
Images for kids
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Mating in Antarctica
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Stuffed chick at Auckland Museum
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In Antarctica
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See also
In Spanish: Pingüino de Adelia para niños
