Fewer Ice Makes Penguins Happier
Researchers have been surprised to find that Adélie penguins in Antarctica prefer sea ice conditions reduced to the lowest level.
As climate models project rapid reduction of the continent's sea ice for the rest of the century, this polar animal could be a rare global warming winner. Their research findings were published this week in Science Advances.
In recent decades, Antarctica has experienced a steady increase in the extent of its sea ice (frozen seawater) even as its polar twin, the Arctic, has suffered through a marked decrease. But this is not expected to last for much longer as the climate changes, with Antarctica also projected to see a decline in its sea ice, with all the consequences of such changes to the maritime habitat for the organisms that live there. But such consequences aren't always negative.
Polar biologists have known for some time that Adélie penguins, the most common species of penguin in Antarctica, tend to see population increases during years of sparse sea ice and suffer massive breeding failures during those years with the greatest growth of sea ice.
Researchers with Japan's National Institute of Polar Research electronically tagged 175 penguins with GPS devices, accelerometers and video cameras across four seasons with different sea ice conditions, allowing them to track penguins on their trips, categorize walking, swimming and resting behavior, and estimate the number of prey captured during dives.
Lead researcher Yuuki Watanabe at the National Institute of Polar Research said in a report: "It turns out that these penguins are happier with less sea ice. This may seem counter-intuitive, but the underlying mechanism is actually quite simple."
He explained that in ice-free conditions, penguins are able to travel more by swimming than by walking.