Lisa O’Dowd warms to one of the coolest creatures of the colder climates, and casts an icy glance at their not-so-glacial decline at the hands of global warming.
In a week that began like any other, an innocent image circled the internet and captured the hearts of many. A camera left rolling by a researcher with the Australian Antarctic Division recorded two Emperor Penguins kicking it over and staring deep into the lens, giving rise to what may be the first penguin selfie. These naturally curious birds were simply investigating a foreign object on their terrain, and it was unintentionally captured beautifully.
As we leave the darkness of winter behind, we must appreciate an animal that withstands and defeats the winter in a place where few dare to go. Antarctica, a massive continent covered in freshwater ice and snow and surrounded by sea ice from the southern ocean, is the ultimate survival test.
“As the only animal to breed during the Antarctic winter, their story has fascinated scientists since they were first described in 1844.”
Ernest Shackleton once described Antarctica as ‘the coldest, windiest, driest and darkest continent on the planet.’ It is home to the Emperor Penguin (Aptenodytes forsteri), the largest of the eighteen penguin species. Doug Allen, a world renowned film-maker recently gave a lecture in Trinity College Dublin. There, he introduced his book Freeze Frame where he describes his own personal account of these birds. “Normally I avoid anthropomorphic descriptions but these birds clearly posess a dignity. They walk with a regal gait, measured and slow, their heads dipping from side to side.”
Emperors have a remarkable life cycle. As the only animal to breed during the Antarctic winter, their story has fascinated scientists since they were first described in 1844. In early April, around 54 colonies gather in the Antarctic. Emperors travel from the open ocean across sea ice for hundreds of miles to the same place every year. Breeding colonies are usually located where the sea ice will be stable for the full breeding sequence and where icebergs and ice cliffs provide shelter from prevailing winds.
“Females lay a single egg. It is crucial that eggs do not touch the ice as they will freeze immediately.”
As colonies continue to increase in size, the initial weeks are spent searching for a mate. From May through early June, females lay a single egg. It is crucial that eggs do not touch the ice as they will freeze immediately. Males incubate the eggs on their brood pouch for roughly sixty days where they endure a time of virtually complete darkness, high winds, and extreme freezing temperatures. Conservation of energy is essential and it is the mechanism of huddling to which they attribute their survival. Females soon leave after the egg has been laid, and go in search for holes in the ice where they can feed.
From late August, chicks begin to hatch but remain protected under their father’s brood pouch until they are about ten days old. It is essential that the mother’s return is synchronised with the chicks hatching so that sufficient food can be provided through regurgitation. If chicks hatch before the females return, males have means to feed the chick for several days from a protein secretion produced in their crop. Following the female’s return, males leave and head for open water where they will spend around twenty days feeding before returning to the colony.
As the sea ice retracts, the parents take frequent turns between brooding and feeding. It is their ability to recognise their partner’s call that allows them to find each other on return. As chicks become too large to reside inside the abdominal pouch of their parents, they begin to form huddles just as the adults do, to conserve heat. Come December the colony breaks up, the chicks dive into the ocean for the first time, and the adults begin their feast until it is again time for their annual migration inland.
Despite their isolation, these birds are not safe from the threats posed by climate change. Emperor Penguins were first listed as Near Threatened on the International Union for Conservation of Nature (IUCN) Red List of threatened species in 2012. It has been projected that they will undergo a moderately rapid population decline over their coming three generations (60 years) due to the effects of predicted climate change.
“It has been projected that they will undergo a moderately rapid population decline over their coming three generations (60 years) due to the effects of predicted climate change.”
Polar regions are extremely sensitive to small variations in temperature. A temperature increase of 2°C in the Earth’s troposphere (forecasted to occur by mid 2040) will result in changes to sea ice and weather patterns. Colonies found north of 67-68° South may be lost entirely. Unlike other species that track climate change latitudinaly, Emperors’ breeding is restricted to a very limited latitudinal range.
It is the Antarctic that is experiencing one of the fastest rates of global warming. Unless action is taken to immediately to reduce global carbon emissions, the future of Emperor Penguins appear bleak. Only time will tell how the next chapter of the extraordinary story of the these birds will unfold.