Around 10,000 young birds are said to have perished in the Antarctic due to a catastrophic die-off of emperor penguin chicks. By this point, it is December, and Antarctica is entering its summer season. The season’s ice soon breaks up, allowing the colony’s newest members to accompany the adults into the ocean in safety to hunt.
Before the chicks could grow the water-resistant feathers required to swim in the ocean, the sea-ice beneath them melted and disintegrated. The birds most likely perished by freezing or drowning. The incident took place in the west of the continent, close to the Bellingshausen Sea, in late 2022.
Satellites captured it for analysis. The wipeout, according to Dr. Peter Fretwell of the British Antarctic Survey (BAS), was a sign of things to come. The existence of ice beneath those little feet is essential to the survival of every new generation of emperor penguins. The uncharacteristically early melting of Antarctica’s winter sea ice last year was terrible for the species, as many biologists had anticipated.
After finishing that investigation, the British Antarctic Survey’s Peter Fretwell, the study’s primary author, claimed he looked at satellite photographs of the remaining 66 colonies of emperor penguins on the continent.
He claimed that in 19 of them, or over 30%, it is thought that the majority, if not all, of the chicks perished by freezing to death or drowning as the ice that had supported them melted into the sea.
Although isolated seasons of unsuccessful breeding can occasionally occur in particular colonies, “this is the first time we’ve really seen a whole area be lost because of the sea ice,” said Fretwell, a mapping specialist.
As the Southern Hemisphere winter nears in March, adult birds leap onto the sea ice. They engage in courtship, copulate, lay eggs, and raise the young from those eggs for several months until it is time for them to venture out into the world on their own.
Before thousands of chicks had a chance to fledge the slick feathers needed for swimming, the sea ice beneath emperor rookeries began to disintegrate in November, as seen by the research team. As a result, four of the colonies completely failed to reproduce. Only the site at Rothschild Island, which is the farthest north, had some success.
Moreover, since 2016, the amount of sea ice that forms during the summer months in Antarctica has been rapidly declining, reaching new lows. The Bellingshausen had essentially no ice cover in either of the two most recent summer seasons, 2021/22 and 2022/23, which were the two lowest years ever recorded.