Emperor penguin facts for kids
Quick facts for kids Emperor penguin |
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| Adults with a chick on Snow Hill Island, Antarctic Peninsula | |
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| Genus: |
Aptenodytes
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| Species: |
forsteri
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| Emperor penguin range (breeding colonies in green) |
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The emperor penguin (Aptenodytes forsteri) is the tallest and heaviest of all living penguin species. They live only in Antarctica.
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Name
Emperor penguins were described in 1844 by English zoologist George Robert Gray. The name consisted of Ancient Greek word elements, meaning "without-wings-diver".
Description
Adult emperor penguins are 110–120 cm (43–47 in) in length, including bill and tail. The weight ranges from 22.7 to 45.4 kg (50 to 100 lb). Males weigh more than females. The weight also varies by season.
Like all penguin species, emperor penguins have streamlined bodies to minimize drag while swimming. Their wings are more like stiff, flat flippers. The tongue has rear-facing barbs to prevent prey from escaping when caught. Like all penguins, the emperor penguin cannot fly.
Males and females are similar in size and colouration. The adult has deep black dorsal feathers, covering the head, chin, throat, back, dorsal part of the flippers, and tail. The underparts of the wings and belly are white, becoming pale yellow in the upper breast. The ear patches are bright yellow.
Diet
Its diet consists primarily of fish, but also includes crustaceans, such as krill, and cephalopods, such as squid.
Fish are usually the most important food source, and the Antarctic silverfish (Pleuragramma antarcticum) makes up the bulk of the bird's diet. The emperor penguin searches for prey in the open water of the Southern Ocean. One of its feeding strategies is to dive to around 50 m (160 ft), where it can easily spot fish swimming against the bottom surface of the sea-ice; it swims up to the bottom of the ice and catches the fish. It then dives again and repeats the sequence about half a dozen times before surfacing to breathe.
Distribution and habitat
The emperor penguin lives almost exclusively between the 66° and 77° south latitudes.
The northernmost breeding population is on Snow Island, near the northern tip of the Peninsula. Individual birds have been seen on Heard Island, South Georgia, and occasionally in New Zealand.
The total population was estimated in 2009 to be at around 595,000 adult birds, in 46 known colonies spread around the Antarctic and sub-Antarctic; around 35% of the known population lives north of the Antarctic Circle.
Predators
The emperor penguin's predators include birds and aquatic mammals. Southern giant petrels (Macronectes giganteus) hunt for chicks. They are responsible for over one-third of chick deaths in some colonies; they also scavenge dead penguins. The south polar skua (Stercorarius maccormicki) mainly scavenges for dead chicks. Occasionally, a parent may attempt to defend its chick from attack, although it may be more passive if the chick is weak or sickly.
The only known predators thought to attack healthy adults, and who attack emperor penguins in the water, are both mammals. The first is the leopard seal (Hydrurga leptonyx), which takes adult birds and fledglings soon after they enter the water. Orcas (Orcinus orca), mostly take adult birds, although they will attack penguins of any age in or near water.
Adaptation mechanisms
Adaptations to cold
The species has adapted in several ways to counteract heat loss. The feathers are very dense and provide 80–90% of the body insulation. It also has a layer of underskin fat which may be up to 3 cm (1.2 in) thick.
Muscles allow the feathers to be held erect on land. This helps to trap a layer of air next to the skin and reduce heat loss. When in water, the plumage is flattened, waterproofing the skin and the downy underlayer.
The emperor penguin is able to thermoregulate (maintain its core body temperature) without altering its metabolism.
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Adaptations to pressure and low oxygen
The bones of the penguin are solid, which eliminates the risk of mechanical barotrauma.
While diving, the emperor penguin uses little oxygen, as its heart rate is reduced to as low as 15–20 beats per minute. Besides, non-essential organs are shut down. This helps the species take longer dives.
Breeding
It is the only penguin species that breeds during the Antarctic winter. Breeding colonies are usually in areas where ice cliffs and icebergs provide some protection from the wind.
Emperor penguins are serially monogamous. They have only one mate each year and remain faithful to that mate. However, do not mate for life: fidelity between years is only around 15%.
The female lays a single egg in May or early June. Then she very carefully takes the egg to the male. This can be awkward and difficult, especially for first-time parents, and many couples drop or crack the egg in the process. When a couple loses an egg in this manner, their relationship is ended and both walk back to the sea. They will return to the colony next year to try mating again.
If the egg is transferred successfully, the female departs for the sea and the male spends the dark, stormy winter incubating the egg. A male emperor penguin must withstand the extreme Antarctic winter cold for more than two months while protecting his egg. He eats nothing during this time. Most male emperors will lose around 12 kg (26 lb) while they wait for their eggs to hatch. The emperor is the only penguin species where this behaviour is observed; in all other penguin species both parents take shifts incubating.
The chick usually hatches before the mother's return, and the father feeds it a curd-like substance composed of 59% protein and 28% lipid, which is produced by a gland in his oesophagus. This ability to produce "crop milk" in birds is only found in pigeons, flamingos and male Emperor penguins. The father is able to produce this crop milk to temporarily sustain the chick for generally 4 to 7 days, until the mother returns from fishing at sea with food to properly feed the chick. If the mother penguin is delayed, the chick will die.
As the chick hatches, parents take turns foraging at sea and caring for their chick in the colony.
Emperor penguin chicks are typically covered with silver-grey down and have black heads and white masks. Chicks weigh around 315 g (11 oz) after hatching, and fledge when they reach about 50% of adult weight.
Female emperors who failed to find a mate to breed with, or have lost their own chick may attempt to adopt a stray chick or steal the chick of another female. The mother of the chick and neighboring females will fight to protect the chick or reclaim it, if it has been successfully stolen.
Chicks which have been adopted or stolen are quickly abandoned once again, as it is impossible for the female to feed and care for the chick alone. The orphaned chicks wander around the colony attempting to seek food and protection from other adults. They will even try to shelter themselves in an adult bird's brood patch already occupied by their own chick. These stray chicks are brusquely driven away by the adults and their chicks. All orphaned chicks will rapidly become weaker and die of starvation, or freeze to death.
Conservation status
In 2012 the emperor penguin was uplisted from a species of least concern to near threatened by the IUCN. Along with nine other species of penguin, it is currently under consideration for inclusion under the US Endangered Species Act.
The species is considered to be highly sensitive to climatic changes. As the sea ice is melting, their habitat is destroyed. Loss of ice reduces the supply of krill, which is a primary food for emperor penguins. Of particular concern is the impact of tourism.
A Woods Hole Oceanographic Institution study in January 2009 found that emperor penguins could be pushed to the brink of extinction by the year 2100. The study constructed a mathematical model to predict how the loss of sea ice from climate warming would affect a big colony of emperor penguins at Terre Adélie, Antarctica. The study forecasted an 87% decline in the colony's population, from three thousand breeding pairs in 2009 to four hundred breeding pairs in 2100.
In June 2014 a study by the Woods Hole Oceanographic Institution concluded that emperor penguins are at risk from global warming, which is melting the sea ice. This study predicted that by 2100 all 45 colonies of emperor penguins will be declining in numbers, mostly due to loss of habitat.
In December 2022, a new colony at Verleger Point in West Antarctica was discovered by satellite imaging, bringing the total known colonies to 66.
Relationship with humans
In zoos and aquariums
Since the 1930s, there have been several attempts at keeping emperor penguins in captivity. Malcolm Davis of the National Zoological Park made early attempts at keeping penguins, capturing several from Antarctica. He successfully transferred penguins to the National Zoological Park on March 5, 1940, where they lived for up to 6 years.
Until the 1960s, keeping attempts were largely unsuccessful, as knowledge of penguin keeping in general was limited and acquired by trial and error. The first to achieve a level of success was Aalborg Zoo where a chilled house was built especially for this Antarctic species. One individual lived for 20 years at the zoo and a chick was hatched there, but died shortly after.
Today, the species is kept at just a few zoos and public aquariums in North America and Asia. Emperor penguins were first successfully bred at SeaWorld San Diego; more than 20 birds have hatched there since 1980. Considered a flagship species, 55 individuals were counted in captivity in North American zoos and aquaria in 1999. In China, the emperor penguin was first bred at Nanjing Underwater World in 2009, followed by Laohutan Ocean Park in Dalian in 2010. Since then it has been kept and bred at a few other facilities in China, and the only confirmed twin emperor penguins (the species normally lays just one egg) hatched at Sun Asia Ocean World in Dalian in 2017. In Japan, the species is housed at Port of Nagoya Public Aquarium and Wakayama Adventure World, with successful hatching at Adventure World.
Penguin rescue, rehabilitation and release
In June 2011, a juvenile emperor penguin was found on the beach at Peka Peka, north of Wellington in New Zealand. He had consumed 3 kg (6.6 lb) of sand, which he had apparently mistaken for snow, as well as sticks and stones, and had to undergo a number of operations to remove these to save his life. Following recovery, on 4 September, the juvenile, named "Happy Feet" (after the 2006 film), was fitted with a tracking device and released into the Southern Ocean 80 km (50 mi) north of Campbell Island. However, 8 days later scientists lost contact with the bird, suggesting that the transmitter had fallen off (considered likely) or that he had been eaten by a predator (considered less likely).
Interesting facts about the emperor penguin
- It is the fifth heaviest living bird species.
- Male emperor penguins take care of the eggs. They warm and protect them for two months before the chicks hatch.
- Only 19% of chicks survive their first year of life.
- 80% of the emperor penguin population are adults five years and older.
- Emperor pengiuns can live up to 20 years, although some individuals can live up to 50 years.
- They moult every year, in January and February, within around 34 days.
- While hunting, the species can remain underwater around 20 minutes, diving to a depth of 535 m (1,755 ft).
- In 1994, a penguin from Auster rookery reached a depth of 564 m; the entire dive took him 21.8 min.
- Breeding colonies of the emperor penguin can contain up to several thousand individuals.
- The emperor penguin breeds in the coldest environment of any bird species; air temperatures may reach −40 °C (−40 °F), and wind speeds may reach 144 km/h (89 mph).
- Emperor penguins use specials vocal calls to communicate
- Vocalizing emperor penguins use two frequency bands at a time. Chicks use a frequency-modulated whistle to beg for food and to contact parents.
- The emperor penguin is a very powerful bird. In one case, a crew of six men, trying to capture a single male penguin for a zoo collection, were repeatedly tossed around and knocked over before all of the men had to collectively tackle the bird, which weighs about half as much as a man.
- As a defence against the cold, a colony of emperor penguins forms a compact huddle (also known as the turtle formation). The birds slowly shuffle, giving each bird a turn on the inside and on the outside.
- The emperor penguin is a social animal. Birds hunt together and coordinate their diving and surfacing.
See also
In Spanish: Aptenodytes forsteri para niños
