How iconic emperor penguins survived last ice age

A change in breeding habits and distinct genetic make up may have helped certain populations of the iconic emperor penguins survive the harsh climate during the last Ice Age, a study contends.

The Ross Sea in Antarctica was likely the refuge for one of the only three populations that survived, noted the researchers who studied how climate change has affected emperor penguins over the last 30,000 years.

Due to there being about twice as much sea ice during the last ice age, the penguins were unable to breed in more than a few locations around Antarctica, explained one of the lead authors Gemma Clucas from University of Southampton.

"The distances from the open ocean, where the penguins feed, to the stable sea ice, where they breed, was probably too far. The three populations that did manage to survive may have done so by breeding near to polynyas - areas of ocean that are kept free of sea ice by wind and currents," said Clucas.

The researchers examined the genetic diversity of modern and ancient emperor penguin populations in Antarctica to estimate how they had been changing over time. They found that emperor penguins that breed in the Ross Sea are genetically distinct from other emperor penguins around Antarctica.

The iconic species is famed for its adaptations to its icy world, breeding on sea ice during the Antarctic winter when temperatures regularly drop below -30 AoC. However, the team discovered that conditions were probably too harsh for emperor penguins during the last ice age and that the population was roughly seven times smaller than today.

The study was published in the journal Global Change Biology.