Ancient Penguins Cleverly Used Secret Hideouts in Antarctica to Survive the Ice Age- Study Reveals

For all we know, penguins are built to tackle the extreme cold weather. But, turns out, the Ice Age was too harsh on them and these birds employed an ingenious survival tactic. The Last Glacial Period (LGP), more commonly referred to as the last Ice Age, reportedly occurred from about 19,500 to 16,000 years ago and only three small populations of penguins survived. Among them, one group, the emperor penguins were smart enough to set up refuge in a secret hideout– the Ross Sea. The Ross Sea is a body of water in the Antarctic, located southeast of New Zealand, according to a 2015 study published in the journal Wiley. 

The study intended to deduce a relationship between population structure and demographic history in certain species to understand the processes of microevolution. This information shall also help scientists to predict the resilience that emperor penguins have exhibited to environmental changes over the past 30,000 years. The researchers compared genetic diversity in modern and ancient populations of emperor penguins in Antarctica and gathered pivotal data on their breeding and foraging patterns during the last Ice Age. The study revealed that increased sea ice during that period made it a struggle for these penguin populations to forage in the region. Basically, Antarctica was once too cold even for its flightless natives.  

Emperor penguins breed on sea ice during Antarctic winters with temperatures falling to as low as minus 22 degrees Fahrenheit. During the last Ice Age, though, the air temperatures were 9 degrees colder, and the total population was also seven times smaller than today. Hence, the three penguin populations went their own ways to survive the unpleasant temperatures. Emperor penguins isolated themselves within the Ross Sea while the other two populations inter-bred from their respective locations along the Antarctic coast. The emperor penguins did not interact with the other populations and eventually developed a genetic signature as their population grew, according to the researchers’ analysis. 

Gemma Clucas, a postdoctoral student in ocean and earth science at the University of Southampton, speculated that the distances from their feeding area, the open ocean to their breeding zones in the stable sea ice was “too far.” This is because there was twice as much sea ice during the Ice Age which restricted the penguin populations from breeding in a variety of locations in Antarctica. Clucas, who is also the lead author of the study, disclosed, “The three populations that did manage to survive may have done so by breeding near polynyas — areas of the ocean that are kept free of sea ice by wind and currents."

The rest two populations of penguins survived in areas of the Adelie Land to the Weddell Sea, or from the Antarctic areas south of Australia to the south of Argentina, respectively. All in all, the researchers concluded that the polynyas in the Ross Sea protected them from extinction during the last ice age and helped them survive until temperatures were pleasant. "It is interesting that the Ross Sea emerges as a distinct population and a refuge for the species. It adds to the argument that the Ross Sea might need special protection,” Tom Hart, a zoologist at the University of Oxford said, per LiveScience. However, the increasing sea ice in the Ross Sea during winter still poses a risk to the penguin populations.