Emperor penguins may be recognized by black color on theback, bright white on the front and colorful yellow or orange feathers aroundtheir necks and heads. They are the tallest with an average of about 4 feet.Fossils recently recovered in the Antarctic peninsula revealed that it used tobe home for a giant penguin (Roberts, S.J. et al, 2017). During the arctic winter, they are the onlyanimal species to inhabit Antarctica open space, where temperature can drop toas low as -60°C. Their body is specially adapted to survive the harsh climate: agood reserve of insulating body fat, multiple layers of scale-like feathers,proportionally smaller beaks and flippers, preventing heat loss.
Their arteriesand veins are situated close together allowing them to recycle their own bodyheat (Australian Arctic Division circular about penguins, June 2017). They choose to live in the most desolate, coldest andwindiest places of the earth during the season of 24-hour darkness. These penguinscan travel up to about 50 miles to reach stable breeding grounds on the thickArctic ice. The emperor penguins are super swimmers and impressive divers. Theiraerodynamic bodies and strong flippers make them excellent swimmers,reaching speeds of 3.4 m/s.
(Freeman, J., 2015). Emperor penguins can stayunderwater for over 22 minutes at a time and can dive over 550m as they huntfor food. They have been found to have an increased ability to store oxygen inthe body, the ability to tolerate low levels of oxygen in the body and theability to tolerate the effects of pressure.British and Australian scientistsdiscovered more emperor penguin colonies on ice shelves (Fretwell, P.T. et al2014).
The average lifespan of emperor penguin is typically 20 years in thewild, even though they live in very extreme conditions where the cold could beunbearable for most animals living on this planet. Although the average lifespan is about 20 years, many scientists estimated 1% of emperor penguinshatched might go to 50 years. According to Trathanet al, most of the emperor penguin population consists of five years and older(Trathan, P. et al, 2011). Fretwellet al., estimated the population of emperor penguins (Aptenodytes fosteri)using a single synoptic survey. Using a combination of medium resolution andVery High Resolution (VHR) satellite, they examined the whole continentalcoastline of Antarctica imagery to identify emperor penguin colony locations.The remotely-sensed images were then analyzed using a supervised classificationmethod to separate penguins from snow, shadow and guano.
Actual counts ofpenguins from eleven ground truthing sites were used to convert theseclassified areas into numbers of penguins using a robust regression algorithm.Fretwell et al found atleast 46 breeding colonies of emperor penguins. They estimated more than200,000 breeding pairs. Based on published values of the relationship betweenbreeders and non-breeders, this translates to a total population of about600,000 adult birds (Fretwell, P et al, 2012). The weight of the adult penguins varies from 50 to 100 pounds (CRCHandbook of Avian Body masses by John B. F Dunning. CRC press (1992), ISBN978-0-8493-4258-5).
Like all penguin species,emperor penguins have streamlined bodies to minimize drag while swimming, andwings that are more like stiff, flat flippers (Williams, Tony D., 1995). The tongue is equipped withrear-facing barbs to prevent prey from escaping when caught. It is hypothesized that the emperor Penguins never walk onsolid ground. The emperor penguin feed mostly on Antarctic silverfish, but sometimesother fish, and some species of squid. When they need to build up their storeof fat, before a molt or at the beginning of breeding season, the food quantityingested is doubled. Emperors are near the top of the Southern Ocean’s foodchain and have few natural predators on land due to the hostile conditions oftheir habitat.
Emperor Penguin chicks are preyed upon by other birds like theSouthern Giant Petrels and South Polar Skua. When they return to the ocean,adults are preyed upon by Killer Wales and Leopard SealMolting:Likefor many wild mammals and birds, prolonged periods of feeding and fasting isnormal phenomenon of life in penguins. The fasting period goes on due tounavailability of food.
During winter season, feeding competes with otheractivities, such as survival priority, for example, molting, reproducing andmigrating. Molting is simply defined as shedding their feathers. Usually Penguins undergo onecomplete molt yearly usually after their breeding season.Penguinsfeed mostly on sea fishes, crustaceans and squids, however, they must stay onland for extended periods when breeding, mainly during incubation.
In addition,penguins entirely replace their whole plumage each year and must spend a longtime fasting ashore because the consequent reduction in thermal insulationprecludes staying in cold Antarctic and sub Antarctic waters for feeding. The duration of fasting of molt varies from2-5 weeks. (Putz and Plötz 1991).To keep themselves warmand dry, the feathers of penguin are very important. In frigid ocean water. Thepenguin’s molt is sometimescalled a catastrophic molt,because unlike most birds that will molt afew feathers at a time, penguins molt allof their feathers all at once (Webster R.K., et al, 2016).
For most penguins, they undergoalternate periods of anorexia on land and hyperphagia at sea. Larger thepenguins, the fast period is longer, whereas, smaller penguin’s fast days are1-3 days. The male emperor penguins support a four month fast. In the middle-sizedpenguins, the duration of breeding fast is about 2 weeks. In the king Penguinspecies, because of the winter food shortage, that temporarily halts theirgrowth varies from 1 – 5 months.