More than 70 percent of the global King penguin population, currently forming colonies in Crozet, Kerguelen and Marion sub-Antarctic islands, may be nothing more than a memory in a matter of decades, as global warming will soon force the birds to move south, or disappear. This is the conclusion of a study published in the journal Nature Climate Change and performed by an international team of researchers.
|More than 70 percent of the global King penguin population may be nothing more than a memory in a matter of decades,|
as global warming will soon force the birds to move south, or disappear [Credit: Robin Cristofari]
King penguins are in fact picky animals: in order to form a colony where they can mate, lay eggs and rear chicks over a year, they need tolerable temperature all year round, no winter sea ice around the island, and smooth beach of sand or pebbles. But, above all, they need an abundant and reliable source of food close by to feed their chicks. For millennia, this seabird has relied on the Antarctic Polar Front, an upwelling front in the Southern Ocean concentrating enormous amounts of fish on a relatively small area.
Yet, due to climate change, this area is drifting south, away from the islands where most King penguins currently live. Parents are then forced to swim farther to find food, while their progeny is waiting, fasting longer and longer on the shore. This study predicts that, for most colonies, the length of the parents' trips to get food will soon exceed the resistance to starvation of their offspring, leading to massive King penguin crashes in population size, or, hopefully, relocation.
|King penguins are picky animals [Credit: Celine LeBohec]|
"Extremely low values in indices of genetic differentiation told us that all colonies are connected by a continuous exchange of individuals," says Emiliano Trucchi formerly at the University of Vienna and now at the University of Ferrara, one of the coordinator of the study. "In other words, King penguins seem to be able to move around quite a lot to find the safest breeding locations when things turn grim."
But there is a major difference this time: for the first time in the history of penguins, human activities are leading to rapid and/or irreversible changes in the Earth system, and remote areas are no exception. In addition to the strongest impact of climate change in Polar Regions, Southern Ocean is now subject to industrial fishing, and penguins may soon have a very hard time fighting for their food.
|Penguins form colonies in Crozet, Kerguelen and Marion sub-Antarctic islands [Credit: Celine LeBohec]|
Source: University of Vienna [February 26, 2018]