How Emperor Penguins Managed to Survive the Harsh Ice Age

During the last ice age, emperor penguins managed to survive some harsh conditions. Now, scientists have taken a closer look at how they managed to exist during this period of climate change.

In order to learn a bit more about the history of emperor penguins, the researchers examined the genetic diversity of modern and ancient emperor penguin populations in Antarctica to estimate how they have changed over time. These penguins are famed for their adaptations and can breed on sea ice during the Antarctic winter, when temperatures regularly drop below -30 degrees Celsius. Conditions during the last ice age were even harsher, however, and the emperor penguin population was likely seven times smaller than today.

"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," said Gemma Clucas, one of the researchers, in a news release. "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."

One of the polynas that probably supported a population of emperor penguins throughout the last ice age was the Ross Sea. In fact, the emperor penguins of today that breed in the Ross Sea are genetically distinct from other emperor penguins around Antarctica.

"Our research suggests that the populations became isolated during the last ice age, pointing to the fact that the Ross Sea could have been an important refuge for emperor penguins and possibly other species too," said Jane Younger, one of the researchers.

That said, the Ross Sea may soon be affected by the climate change of today. Due to changes in wind patterns, the Ross Sea has recently experienced increases in the extent of winter sea ice. That said, this trend is expected to reverse by the end of the century.

The findings are published in the journal Global Change Biology.

For more great science stories and general news, please visit our sister site, Headlines and Global News (HNGN).