Birds breed or live in Antarctica and nearby islands. The most famous bird is of course the penguin.
There are 18 species of penguins in the southern water, seven of them live around Antarctica. This flightless birds are found from the equator to the coast of Antarctica. They are well adapted for cold with their dense overall plumage. Best adapted are the emperor penguin, the largest ones
They laid single, 13cm long eggs which weight 0.4kg on ice and held them on feet. The male takes charge of the precious egg within a few hours, balancing it carefully on his feet and covering it with a special fold of abdominal skin. The female return to the sea for a month to feed. For 65 day, in temperatures down to -45°C and blizzards up to 200km/h, the males incubate the egg. They keep as still as possible and huddles close to his fellows to conserve body heat. During this time they eat nothing, and only has snow to drink. As a result, male penguins lose 40% of their body weight. Some cannot endure the fast and abandon their eggs and head for the sea to feed.
For those that stick it out, relief comes with the return of the females in mid-July, just as the chick is hatching. With amazing accuracy, partners recognise each other’s calls amongst the thousands of others, and the chick is transferred to the mother’s feet and pouch. While she feeds it regurgitated fish on demand, the male is free to find his first meal in four months. But this is still a two-day journey across 80km of pack ice to the open sea. When he gets there, he may dive to over 300 m to find food.
After three weeks the males return to relieve the females. By the next changeover the chicks are big enough to be left in creches so that both parents can bring food to them. By mid-December, they have reached 60% of their adult body weight, shed their fluffy down for a smart dinner suit and are ready to try their luck in a new environment, the sea. Although 30% or more don’t make it to this stage, those that do have a good chance of living at least 20-30 years.
Emperors are so big they need nine months to complete their breeding cycle. They can just fit this into the period of the annual freezing and break-up of the pack ice. But to do so, the males must endure a harsh winter fast, and the chicks have to risk hatching very early in spring.
The males arrive a few days before the females, to occupy the nest space. After courtship, they build their pebble nests and the two eggs are laid a few days apart. The females then return to the ocean to feed a diet of krill and larval fish. The male incubates the egg for seven to 10 days, after which the female returns for a similar shift. The partners then alternate duties for the rest of the 33-day incubation period.
The parent warm the chicks for two or three weeks before forming crèches. Then the young birds leave the colony to spend their first two years at sea or on the pack-ice.
In the south they nest on bare, open ground, sometimes sharing colonies with chinstraps and Adélies. On the northern islands they nest in the shelter of tussock grass. They lay two almost spherical eggs the size of tennis balls, which have rough, bluish-white shells. These are incubated by the male and female in turn for 35 days.
Gentoos are probably the fastest swimmer of all birds. They’re capable of bursts of speed of up to 21 to 27 km/h. They feed mainly on krill and other fish, and can dive to depths of 100m or more.
Chinstrap penguin pygoscelis antarctica, with an average weight of 4.5kg and a height of 68cm, is the smallest of the three Pygoscelis species. With their population of 10 million the occur mostly on South Orkney, South Shetland and South Sandwich Islands and along the western shores of the Antarctic Peninsula.
Chinstraps nest on rock, sloping ground. Females take the first incubation watch over two eggs and parental duties are shared once the chicks hatch. The young birds leave the colonies within nine weeks, and are able to feed themselves of krill.
They have a similar breeding behaviour like the emperor, they lay only one egg at a time, which they carry around on their feet for the 15 day of incubation. They cover the egg with a fold of skin called brood patch to transfer the heat from the adult body to the egg. The chicks are dependent for almost a year and are feeded on a diet of fish and squid. The parents dive hundred times but often very unsuccessful. Scientists have estimated that of 500 to 1’200 dives made by king penguins, about half are greater than 50m. The deepest recorded dive for this species of penguin is 250m, only the emperor penguin can dive deeper.
The King penguin have a very special breeding cycle which raise two chicks in three years. In the first year, breeding starts in October. The eggs are laid in November and hatch from mid-January. Both parents share incubation. By mid-April the chicks have reached 90% of adult body weight but are not year fledged. They huddle together through the winter with only infrequent feeds from their parents.
Next spring, with plenty of food available again, they grow quickly, moult and leave the colony. Their parents spend this second summer at sea then return to breed, laying eggs which hatch in March. These new chicks are also abandoned in winter, with much less chance of survival than their following third summer feeding them so they are ready to leave the colony by autumn. Then for the parents the cycle begins again the following October.
Eudyptes chrysocome is with 55cm height and a weight of 2.5 kg the smallest penguin around Antarctica. They breed in nest on the cliffs and scree slopes of islands close to and north of the Antarctic Convergence.
They lay two eggs of different sizes. Some pairs incubate in 35 day both eggs but usually only one survives. Chicks leave the colonies when they are around 70 days old. They are the most aggressive of all penguins and often found in company of macaronis.
Eudyptes chrysolophus is 71cm tall and weigh 4kg. They spend the winter at sea and return to their colonies on the inner and outer Antarctic islands to engage in lively courtship. Macaronis lay two eggs in their sparse nest. The first egg, which is 50 per cent smaller than the second, usually survives rarer. After 35 days of incubation, the surviving chick is guarded by the male for the first three weeks while the female periodically returns with krill.
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