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Saturday, October 10, 2009

Emperor Penguins may go extinct by 2100

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The declining food availability due to the effects of climate change and industrial fisheries killing the populations of crustaceans and fish, destruction of habitat, and human disturbance at breeding colonies, bad impact of tourism are driving the emperor penguins towards extinction. The International Conservation Union has placed the Emperor Penguins in the list of the least concerned species. The authorities in the U.S. are thinking to bring the emperor penguins under the U.S.Act of Endangered species. The abnormally prolonged period of warmth resulting into reduced sea ice coverage had been reported to cause female adult mortality resulting into a 50 percent decline of their population during 1970s in Terre Adélie region.Increse in the sea-ice extent causes significant decrease in rate of hatching of eggs of penguins, and this is also an important cause behind the female mortality of this species. Thus it can be concluded that emperor penguins are rather more vulnerable to the changing conditions of climate. A study done at Woods Hole Oceanographic Institution during January 2009 explains that Emperor Penguins could be pushed to the point of extinction by 2100 due to climate change and melting of Antarctic ice.

The taxonomic position and morphological characteristics

Penguins belong to Aves, the class of Birds under the Phylum Chordata of animal kingdom. Combining its names of genus and species as per the binomial system of the zoological nomenclature its full zoological name is Aptenodytes forsteri (Gray, 1844).The emperor Penguin is the tallest and heaviest of all the living penguin species of the world. It is endemic to Antarctica. The male and female are similar in plumage and size, reaching 122 cm (48 in) in height and weighing anywhere from 22 to 45 kg (48 to 99 lb). The dorsal side and head are black and sharply delineated from the white belly, pale-yellow breast and bright-yellow ear patches. Like all penguins it is flightless, with a streamlined body, and wings stiffened and flattened into flippers for a marine habitat. The emperor penguin is a great hunter. While hunting, it can remain under icy water even up to 18 to 20 minutes diving up to a depth of 535 to 550 m. To facilitate this exercise the emperor penguin has several adaptations like – a complex type of hemoglobin in its blood which allows it to function even at extremely low oxygen level, solid bones, and the ability to reduce the rate of metabolism and the ability to shut down all the organs that don’t have to function during a particular period. According to a report published in the Science Daily, dated January 27, 2009 – “The Emperor penguin is the largest of all the penguins. They are also one of the most biologically interesting. Concentrated in the Weddell Sea and Dronning Maud Land, Enderby, Princess Elizabeth Lands, and the Ross Sea, Emperors remain in Antarctica permanently, breeding on the sea ice in some of the coldest conditions on Earth. They do not build nests or defend a fixed territory, using their warm bodies instead to incubate and raise their young. This unique breeding behavior--Emperors are the only Antarctic bird that breeds in winter--may have developed to allow chicks to grow to independence at a time when food is most plentiful and predators are few.”

Special features- Adaptations and reproductive cycle

The survival of Emperor Penguins in an extremely cold climate like that of Antarctic is ensured by its unique adaptations. The Emperor Penguin has short wings that help it to dive even up to 900 feet to catch the fish. It can swim at the speed of 10 to 15 km per hour which helps it to escape from its enemy which is usually the leopard seal as its main enemy. These birds have thick layers of feathers, a layer of fat under the skin and large amounts of body oil which helps in keeping dry while in the water.

The specific feature of emperor penguins, unlike other birds is its breeding season which is winter. These birds are the only to live in the coldest climate on the earth. These can survive even when the temperature drops as low as -140 degrees Fahrenheit on the ice of Antarctica. The adult emperor penguin treks from 50 to 120 km over the ice to reach to breeding colonies that sometimes comprise thousands of individuals, during the Antarctic winter period ranging from March to December. The female lays a single egg, to which it transfers to the male and moves away on a long journey on the ice. There she feeds and recovers her lost health for the whole season and comes back to the male to whom she recognizes by his specific call. The egg is incubated by the male while the female remains on her long journey for hunting or foraging.

The incubation is done on the male's feet under a thick fold of skin that hangs from the belly of the male. The males manage to survive by standing huddled in groups for up to 9 weeks. During the time of incubation of the egg the male has to remain of fast due to which it looses more than half of its weight. However, soon after the female returns, the male goes to the open sea to feed and recover his lost health. After the male returns back within a few weeks, both the parents cooperate in warming the chick and feeding food from their stomachs. After remaining under parental care for about seven weeks, the chick joins its group and all of them huddle together for the warmth and protection. Chicks can still identify their parents by their sound and specific calls. They are still fed by their parents. It takes about six to seven months for a chick to become mature or grown up and usually it happens to be the summer in the Antarctic. This is the time when all the penguins go to the open sea. The life span of emperor penguin is reported to be up to 20 years. However some researchers are of the opinion that it can survive even up to a period of 50 years in the wild.

Picture: Emperor Penguins - males in the front line incubating chicks
on their feet under folds of their skins
credit - Science Daily.Jan. 27, 2009

The Center for Biodiversity one of the premier organisations of the world working in the field of conservation of biodiversity and environment quotes its activities published in The Associated Press, October 7, 2009 -

Two advocacy groups announced plans today to sue the Obama administration unless it reverses a Bush-era decision denying penguins a place on the endangered species list.The Center for Biological Diversity and the Turtle Island Restoration Network say Antarctica's emperor penguin -- protagonist of the documentary "March of the Penguins" -- and two species of rockhopper penguin face extinction from the dual threats of climate change and industrial fishing.The Interior Department in December contested that notion, saying impacts from global warming on penguins were too uncertain to merit an Endangered Species Act listing.The groups said today that they would sue in 60 days unless the Fish and Wildlife Service -- the Interior agency that deals with endangered species -- reverses that decision and reopens a review of the penguins' status."If the Obama administration is serious about restoring scientific integrity to government decision-making, it will stand behind the sound science showing that global warming is threatening the emperor penguin and protect this species before it's too late," said Shaye Wolf, a biologist with the Center for Biological Diversity.Fish and Wildlife declined to comment on the announcement.Listing penguins would require Interior to set strict regulations for the U.S. longline fishing fleet in the Antarctic, whose gear can entangle and drown penguins, Wolf said.The groups also hope the listing would bolster the link between species protections and regulation of greenhouse gas emissions. Penguins' sea ice habitat is melting because of global warming, which also threatens some of the fish and krill populations the seabirds depend on, Wolf said.In this and other attempts to garner federal protection for species threatened by global warming, environmental groups have argued that protecting those species requires the federal government to regulate carbon dioxide emissions.When listing the polar bear, the Bush administration published a special rule prohibiting endangered species reviews from taking greenhouse gas emissions into account. The rule was later upheld by the Obama administration, but environmental groups are hoping to reverse it through litigation.

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