Satellite data indicate that satellite data indicates thousands of emperor penguins from western Antarctica have lost their chicks due to the receding sea-ice.
Sea ice has been decreasing over the past two decades. Reach record lowsAntarctica is a large part of the continent (SN: 7/5/23). Peter Fretwell noticed, while viewing satellite images from 2022 that ice was melting early in the year in a particular area. He and his colleagues wanted to measure the impact of this ice loss — in the Bellingshausen Sea off western Antarctica — on emperor penguins (Aptenodytes forsteri( in the region.
Researchers looked at Satellite ImagesThe breeding season is determined by the colonies (SN: 8/4/20). Five colonies were observed. Four of the four have probably lost their entire clutchThe team’s report for August 23 is Communications Earth & Environment.
During their breeding season (April to January), the Emperor penguins depend on stable sea ice. The newborn chick, when an egg hatches must fledge. It loses its downy fur to gain its waterproof coating.
In 2022 the sea ice melted before certain colonies finished fledging. Fretwell explains that without waterproof feathers, fledging bird colonies were not able to survive. Of the youngsters from the 10,000 or so breeding pairs in the region, “we think about 850 of the chicks survived,” says Fretwell, of the British Antarctic Survey in Cambridge, England.
Penguin colonies can recover from a single failed breeding season, says Annie Schmidt, a seabird ecologist at Blue Point Conservation Science in Petaluma, Calif., who wasn’t involved in the new study. Researchers only looked at a small number of the 62 emperor penguin colony in Antarctica.
Some of the other colonies in recent years have also had bad breeding seasons. On Antarctica’s Brunt Ice Shelf, the world’s second-largest emperor penguin colony at the time had Three years of breeding failureFretwell, a colleague and I reported that the sea ice was broken up by storms from 2016 until 2018. This colony almost disappeared due to mass emigration and failure of breeding.
If the failure is repeated or widespread, it could endanger colonies, and eventually, all emperor penguins.
The new study, documenting breeding failure across several colonies at once, “is the first observation that’s in line with the worst expectations of what could happen” as the Earth continues to warm, Schmidt says. “I’m concerned — it’s not a good sign.” Recent estimates predict that the changing climate and melting sea ice Could reduce emperor penguin population by halfBy 2100.
Fretwell is not discouraged despite a potentially bleak outlook for the emperor penguins. “If we can slow down global warming … we can turn around the fate of the emperor penguin,” he says. “But that window of opportunity is getting smaller, so we really have to act now.”
