The emperor penguin may well be the first polar species to become extinct due to global warming. According to a scientific study published Thursday, August 24, all the chicks have died in several Antarctic colonies due to the record melting of the sea ice in recent months.

Of five colonies studied in the Bellingshausen Sea region of West Antarctica, all but one suffered a “catastrophic” loss of 100% of chicks, which drowned or froze to death when the ice yielded under their paws. They weren’t mature enough to face such conditions, researchers report in Communications: Earth

“This is the first major breeding failure of emperor penguins in multiple colonies at the same time due to melting sea ice and is likely a sign of what to expect in the future,” he said. Agence France-Presse (AFP) the main author of the study, Peter Fretwell, a researcher at the British Antarctic Survey.

“We’ve been anticipating this for some time, but seeing it actually happen is grim,” he added.

30% of colonies were affected by melting

During last year’s Southern Hemisphere spring, from mid-September to mid-December, Antarctic sea ice melted at record speeds. However, this early melting occurred in the middle of the emperor penguins’ already complex and fragile reproductive period.

These seabirds reproduce in the middle of the austral winter, when the temperatures are the harshest, a process that takes many months, between mating, brooding and the time when the chicks are autonomous, thanks in particular to the training impermeable feathers, generally around January-February.

Emperor penguins, aka Aptenodytes forsteri, number around 250,000 breeding pairs, all in Antarctica, according to a 2020 study. Colonies in the Bellingshausen Sea account for less than 5% of that total. “But overall, about 30% of colonies were affected by melting last year. So there will be a lot more chicks that don’t survive,” says Fretwell.

Each year, starting in March, the adults embark on a journey of up to a hundred kilometers to reach their breeding sites on the pack ice, which are always the same. The females lay a single egg and leave it for the male to fetch food, sometimes hundreds of miles away.

The males keep the eggs warm, on their legs, covering them with a fold of skin forming an incubator pouch, all without moving or eating, while waiting for the foster mothers to return.

Disappearance by 2100?

This immutable ritual, recounted in the film The March of the Emperor, a great public and critical success in 2005, is now suffering the effects of climate change, which until recently seemed to spare the Antarctic sea ice.

Emperor penguins are certainly able to find alternative sites, but the unprecedented peaks of melting since 2016 threaten to exceed their capacities of adaptation, believe the scientists. “Such a strategy will not be possible if breeding habitat becomes regionally unstable,” the study authors say.

The US Wildlife Authority recently listed the emperor penguin as an endangered species.

In addition to the endangerment of its breeding grounds, it is also weakened by the acidification of the oceans, another effect of global warming, which threatens certain crustaceans on which it feeds. The British Antarctic Survey estimates that at the current rate of global warming, nearly all emperor penguins could be extinct by the end of the century.