Emperor penguin babies have experienced a catastrophic die-off in the Antarctic, where it is estimated that up to 10,000 young birds perished. Before the chicks could grow the water-resistant feathers required for ocean swimming, the sea ice beneath them melted and disintegrated.
The birds most likely perished from freezing or drowning. In the west of the continent, close to the Bellingshausen Sea, the incident took place in late 2022. Satellites took pictures of it. A foreshadowing of things to come, according to Dr. Peter Fret well of the British Antarctic Survey (BAS), was to wipe out.
By the end of the century, it is anticipated that more than 90% of emperor penguin colonies would be virtually gone as the continent's seasonal sea ice melts due to global warming. Emperors require sea ice as a solid platform for their breeding cycle and to raise their young. These birds are in danger, he warned BBC News, if the ice is not as thick or breaks up more quickly than it should.
The carbon emissions that are driving the warming can be reduced, thus there is hope. But if we don't, we'll push these recognizable, stunning birds to the brink of extinction. At Rothschild Island, Verdi Inlet, Smyley Island, Bryan Peninsula, and Pfrogner Point, there are five colonies that were monitored by the scientists in the Bellingshausen Sea area.
They were able to track the penguins' behavior by looking at the guano, or excrement, they left on the white sea ice, using the Sentinel-2 satellites of the EU. Even from orbit, this brown smear is apparent. Around March, when winter in the Southern Hemisphere draws near, adult birds leap onto the sea ice. They engage in courtship, copulate, lay eggs, brood those eggs, and then feed their nestlings for several months until the young are ready to venture out into the world on their own.
Smyley Island's emperor colony will disappear in 2022
Source: Copernicus Sentinel-2
When the young birds set out into the water in December or January, this typically happens. In November, however, before thousands of chicks had a chance to fledge and develop the slippery feathers necessary for swimming, the research team observed sea-ice under emperor rookeries fragment. As a result, breeding completely failed in four of the colonies. Only the facility that was the farthest north, on Rothschild Island, had some success.
Since 2016, there has been a rapid decline in the extent of frozen water surrounding the Antarctic continent, reaching new record lows. The Bellingshausen had essentially no ice cover in the summers of 2021/22 and 2022/23, which were the two years with the lowest levels of ice. Additionally, because floes have been forming slowly in recent months, the colonies won't likely start producing chicks for at least another year.
Normal maximum sea ice extent for the winter, which is typically reached in September, will track much below that level. The effects of this change in circumstances, according to Dr. Fretwell and colleagues, were being felt by the emperors. Between 2018 and 2022, a third of the more than 60 known colonies of emperor penguins saw some type of sea-ice impact, whether it was ice that formed later in the season or broke up early.
In the Arctic, on the other side of the earth, the sea ice has been steadily vanishing for many years. In comparison, the Antarctic appeared to be stronger. Up until 2016, it was expanding a little bit each year.
Dr. Caroline Holmes, a BAS colleague, is an authority on Antarctic sea ice. She attributes the current fall to unusually warm ocean water surrounding the continent and a specific wind pattern, which in the case of the Bellingshausen has forced ice back toward the coast, making it impossible for it to expand.
Sea ice thickness
She claimed that these were amazing times. “What we're witnessing right now is so different from what we've previously noticed. We anticipated change, but I don't believe we anticipated it to happen so quickly,” she told BBC News.
Studies in the Arctic have indicated that if we could find a way to stop global warming, the polar north's sea ice would recover. We don't know if it would be true in the Antarctic. However, there is every reason to believe that the sea ice would reform if it became sufficiently cold. Emperors are currently listed as “Near Threatened” by the International Union for Conservation of Nature (IUCN), which compiles the lists of the planet's most endangered species.
Because of the threat that climate change poses to the emperors' way of life, it has been suggested that they be moved up into the more urgent “Vulnerable” category.
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