The life of the average Antarctic penguin chick is harsh enough at the best of times. But if predators and appalling weather were not enough to worry about, the birds now face something rather more menacing: a giant iceberg with the ominous name BI5A.
And its 1,200 square miles of ice and snow is floating between them and their next square meal.
According to scientists, as many as 50,000 penguin chicks face a cold, lonely and very hungry Christmas because B15A has blocked the birds’ route to open water and forced their parents to waddle more than 60 miles to find food.
The iceberg also threatens supply routes to three Antarctic research stations on the McMurdo Sound coast, where a US icebreaker and three cargo ships are scheduled to arrive next month.
Lou Sanson, chief executive of Antarctica New Zealand, called the iceberg "the largest floating thing on the planet right now".
It is part of an even bigger iceberg that broke loose from the mainland in 2000 and split into two in November 2003.
US experts reckon B15A contains enough fresh water to supply Egypt’s Nile River complex for 80 years – or to satisfy the water requirements of the UK population for 60 years.
It was drifting north at about 1.2 miles a day when it wedged between the land and a tiny island, where it now stops the wind and currents breaking up the thick layer of ice covering coastal waters. "There is more blocked ice in McMurdo Sound than we’ve ever recorded in living history for this time of year," Mr Sanson said.
The blocked ice causes real problems for the 50,000 breeding pairs of Adele penguins stranded miles from the open sea, where they catch krill to feed themselves and their growing chicks.
Keith Reid, a penguin expert with the British Antarctic Survey in Cambridge, said: "Adeles will often walk a long way back to their colonies to breed in the expectation the ice will disappear during the time they are incubating the eggs. But that’s not been happening, the ice hasn’t been blowing out."
Thousands of eggs are now hatching. "The adult penguins commute across the sea ice to the sea for food and this big iceberg has created a much longer walk," said Dr Reid. "It costs them a lot of energy to walk instead of swimming."
The adults will use all their food in the struggle back to the nests. And when they realise they cannot feed their chicks they will abandon them.
Biologists in New Zealand predict that only 10% of the breeding penguins will raise a chick this season – bird numbers in the?colonies could fall by up to 70%. Dr Reid said populations should recover in time.
Rescue is out of the question. "The Americans, New Zealanders and Italians are having difficulty getting their ships in to resupply their bases," Dr Reid said. "So it’s difficult to imagine them flying down a few tins of pilchards to feed several thousand penguins."