Facts about Emperor Penguins
The Emperor Penguin is the tallest and heaviest of all living penguin species. Their tongue is equipped with rear-facing barbs to prevent prey from escaping when caught. As a defence against the cold, a colony of Emperor Penguins forms a compact huddle (also known as the turtle formation) ranging in size from ten to several hundred birds, with each bird leaning forward on a neighbour. Those on the outside tend to shuffle slowly around the edge of the formation, producing a slow churning action, and giving each bird a turn on the inside and the outside. The male and female Emporer Penguins are similar in plumage and size. The adult Emperor Penguin has deep black dorsal feathers, covering the head, chin, throat, back, dorsal part of the flippers, and tail. The average yearly survival rate of the Emperor Penguin has been measured at 95.1%, with an average life expectancy of 19.9 years. An Emperor Penguin can hold its breath anywhere up to 20 minutes. Egg of this penguin represents just 2.3% of its mother's body weight, making it one of the smallest eggs relative to the maternal weight in any bird species. After laying, the mother's nutritional reserves are exhausted and she very carefully transfers the egg to the male, before immediately returning to the sea for two months to feed. The Emperor Penguin is the only species where this behaviour is observed; in all other penguin species both parents take shifts incubating. They can dive over 550 meters (1,800 ft). As male Emperor Penguin incubates the egg for all its incubation time, therefore by the time the egg hatches, the male will have fasted for around 115 days since arriving at the colony. To survive the cold and winds of up to 200 km/h (120 mph), the males huddle together, taking turns in the middle of the huddle. They have also been observed with their backs to the wind to conserve body heat. In the four months of travel, courtship, and incubation, the male may lose as much as 20 kg (44 lb), from around 38 kg to just 18 kg (84 lb to 40 lb). Keeping in mind that males incubate the eggs, if the chick hatches before the mother's return, the father feeds it a curd-like substance composed of 59% protein and 28% lipid, which is produced by a gland in his esophagus. 15.7% of the weight of an Emperor Penguin egg is shell. (The shell is relatively thick to minimise risk of breakage). The adult Emperor Penguin stands up to 122 cm (48 in) tall. These penguins weigh anywhere from 22 to 37 kg (48–82 lb). Studies of penguin behaviour and genetics have proposed that the Emperor Penguin is basal; in other words, that it split off from a branch which led to all other living penguin species. Mitochondrial and nuclear DNA evidence suggests this split occurred around 40 million years ago. They are an efficient swimmer, the Emperor Penguin exerts pressure with both its upward and downward strokes while swimming. The upward stroke works against buoyancy and helps maintain depth. Only 19% chicks of Emperor Penguins survive their first year of life. Hatching of their chicks may take as long as two or three days to complete, as the shell of the egg is thick. Their average swimming speed is 6–9 km/h (4–6 mph). Both male and female Emperor Penguins forage for food up to 500 km (311 mi) from colonies while collecting food to feed chicks, covering 82–1,454 km (51–904 mi) per individual per trip. It disperses into the oceans from January to March. Moulting is rapid in this species compared with other birds, taking only around 34 days. Their chicks weigh around 315 g (11 oz) after hatching, and fledge when they reach about 50% of adult weight. As the species has no fixed nest sites that individuals can use to locate their own partner or chick, the Emperor Penguin must rely on vocal calls alone for identification. It uses a complex set of calls that are critical to individual recognition between parents, offspring, and mates, displaying the widest variation in individual calls of all penguins. Their lifespan is typically 20 years in the wild, although observations suggest that some individuals may live to 50 years of age, although only 1% of the total penguin population would reach the age of 50 years. Their egg is vaguely pear-shaped which measures around 12 × 8 cm (4¾ x 3 in) and weighs 460–470 g (1 lb). Emperor Penguin feathers emerge from the skin after they have grown to a third of their total length, and before old feathers are lost, to help reduce heat loss. New feathers then push out the old ones before finishing their growth. Moulting is rapid in this species compared with other birds, taking only around 34 days. The Emperor Penguin's dark plumage fades to brown from November to February, before the yearly moult in January and February. Like all penguin species, it has a streamlined body to minimise drag while swimming, and wings that have become stiff, flat flippers. Both male and female penguins lose substantial mass while raising hatchlings and incubating eggs. The Emperor Penguin's predators include birds and aquatic mammals; the Southern Giant Petrel is the predominant avian predator, responsible for up to 34% of chick deaths in some colonies. Other predators include South Polar Skua, Leopard Seal and Ocra. Their yearly reproductive cycle begins at the start of the Antarctic winter, in March and April, when all mature Emperor Penguins travel to colonial nesting areas, often walking 50 to 120 km (30 to 75 mi) inland from the edge of the pack ice. Emperor Penguins are serially monogamous, or in other words they have only one mate each year, and stay faithful to that mate. However, fidelity between years is only about 15%. The Emperor Penguin is able to breed at around three years of age, and usually commences breeding around one to three years later. |
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