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Antarctica: Thousands of emperor penguin chicks wiped out



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Thousands of emperor penguin chicks drowned when the sea-ice on which they were raised was destroyed in bad weather

The catastrophe occurred in 2016 in Antarctica's Weddell Sea. the colony at the edge of the Brunt Ice Shelf has collapsed with adult birds showing no sign of trying to re-establish the population.

And it would probably be worthless for them to try as a giant iceberg is about to break the site.

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The evolutionary chasm of the Brunt Ice Shelf may have done the colonies anyway

The dramatic loss of the young emperor birds is reported by a team from the British Antarctic Survey (BAS)
                

Drs Peter Fretwell and Phil Trathan noticed the disappearance of the so-called Halley Bay colonies in satellite pictures.

It is possible even from 800km to spot the animals' excrement, or guano, on the white ice and then to estimate the likely size of any gathering

But the Brunt population, which had sustained an average of 14,000

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DigitalGlobe, and Maxar company

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2015: The guano stains at Halley colonies are visible from space
                

Emperors are the tallest and heaviest of the penguin species and need reliable patches of sea-ice on which to breed, and this ice platform must persist from April, when the birds arrive, until December, when their chicks fledge. ] If the sea-ice breaks up too early, the young birds will not have the right feathers to start swimming

This is what happened in 2016.

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Media caption Curious emperor penguins take a selfie video in Antarctica

Strong winds, which have been dulled out of the sea-ice that has stuck hard to the side of the thicker Brunt shelf in its creeks, and never properly reformed. Not in 2017, nor in 2018.

Dr Fretwell told BBC News: "The sea-ice that has been formed since 2016 has not been as strong as Storm events that occur in October and November will now blow it out early. "

The BAS team believes that many adults have either avoided breeding in these later years or moved to new breeding sites across the Weddell Sea. A colony some 50km away, near the Dawson-Lambton Glacier, has seen a big increase in its numbers

Media caption Peter Fretwell: "Storms can now go out the emperors' sea-ice in October and November "

Quite why the sea-ice platform on the edge of the Brunt shelf failed to regenerate is unclear. There is no obvious climate signal to point to this case;

But the sensitivity of this colony to shifting sea-ice trends illustrates, says the team, the impact that future warming in Antarctica could have on the Brunt reveal little in the way of change. emperor penguins in particular

Research suggests that the species could lose anywhere between 50% and 70% of its global population by the end of this century, if sea-ice is reduced to the extent that computer models envisage.
Digitalglobe, and Maxar company

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2018: The Dawson-Lambton Colony has increased its numbers
                

Dr Trathan said: "What is interesting for me is not that colonies move or that we can have major breeding failures – we know that. the climate change refuge for those cold-adapted species like emperor penguins.

"And so if we see major disturbances in these refugees – where we have not seen changes in 60 years – that's an important signal."

Whether the Halley Bay Colony has a real future is a moot point.

Media caption Media caption Scientists have called for special status to protect coral, penguins and other wildlife in Antarctica.

The Brunt Ice Shelf is split by a developing crack.

This chasm will eventually calve an iceberg the size of Greater London into the Weddell Sea, and any sea-ice stuck to the berg's edge may break in the process

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Emperors are the tallest and heaviest of the penguin species
                


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