Second only to Emperor penguins in size, King Penguins - distinguished by their ear patches of bright golden-orange feathers - thrive on the islands at the northern reaches of Antarctica, with a total population of over two million breeding pairs.
Because King penguins sit on the food chain in their region, they are sensitive indicators of alterations to the marine ecosystem and feel the effects of climate change more keenly as a result - in this case, the warming is reducing their food supply.
Global warming is happening much more quickly in some parts of the frozen continent, particularly the north-west area known as the Antarctic Peninsula, where in the last 50 years temperatures have risen by about 2.5ºC - as much as five times the world average.
But for these penguins, which do not live near the peninsula, the effects are caused by a warming of sub polar sea surface temperatures.
A decade ago, Yvon Le Maho of the CNRS Institut Pluridisciplinaire Hubert Curien, Strasbourg, and an engineer began a study of the breeding and survival of penguins on Possession Island in the Crozet Archipelago in the southern Indian Ocean that continued over the course of nine years, marking the birds with electronic tags under the skin as the penguins migrated.
With CÃƒ©line Le Bohec and colleagues, Dr Le Maho shows today in the Proceedings of the National Academy of Sciences that high sea surface temperatures in the penguins wintering range, where two thirds of the world's population of this species reside, diminished the amount of available marine prey, which decreased the survival of adult King penguins since they had to travel greater distances to find food.
The birds feed on small fish and squid, relying less on krill and other small crustaceans than many other sea mammals, and the find suggests that these species are suffering as a result of warming of the Southern Ocean.
Using a mathematical model, the scientists calculate that there will be a nine per cent decline in the adult penguin population for every 0.26ºC of sea surface warming, suggesting that this population is at high risk under current global warming conditions, which predict an average increase of 0.2ºC per decade for the next two decades.
They conclude that there is a "heavy extinction risk" given current global warming predictions of a 0.4ºC rise over two decades, which cuts the chance of survival from 95 per cent to 80 per cent.
King penguins breed on seven sub-Antarctic island groups with large populations on the Falkland Islands, Macquarie Islands, Heard Island, Iles Crozet and Marion island and other sea birds will face similar problems.
A recent report by the environmental conservation group WWF is warning that rising temperatures and the resulting loss of sea ice is robbing other species of the emblematic birds of the nesting grounds they need to breed successfully while lading a reduction in the availability of krill which they rely on for food.
The most vulnerable is the biggest, the Emperor, but the Gentoo, Chinstrap, and AdÃƒ©lie have also suffered dramatic drops in population, according to the Antarctic Penguins and Climate Change report.
© 2008 The Telegraph