The lack of sea ice around parts of Antarctica because of global warming may be good news for one species of penguin, a new study suggests.
Surprisingly, Adelie penguins appear to prefer reduced sea-ice conditions, meaning that the species “could be a rare global warming winner,” according to a statement.
“It turns out that these penguins are happier with less sea ice,” said lead researcher Yuuki Watanabe from Japan’s National Institute of Polar Research. “This may seem counterintuitive, 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.
“For penguins, swimming is a whopping four times faster than walking,” he said. “They may be sleek in the water but are pretty slow waddlers over land.”
Researchers from Japan’s National Institute of Polar Research strapped GPS trackers and video cameras to 175 penguins to track the penguins’ behavior over several years.
In seasons with heavy sea ice, penguins tired out as they waddled to find food. But when there was less sea ice, the penguins were able dive anywhere they want, often just entering the water right by their nests, Watanabe said.
This is more energy- and time-efficient and it expands their foraging range, the study suggests. In fact, the researchers found that the penguins may have expended an average of 15% to 33% less energy per trip compared with ice-covered seasons, putting that saved energy into growth and reproduction.
Since climate models predict that the Antarctic will rapidly lose sea ice as the 21st century progresses, the results suggest that Adélie penguins may experience a population boom in the years to come.
But the new research noted that, according to previous studies, other Adélie penguin populations that reside in warmer, sea-bordering regions (about 30% of the species) do not fare as well when sea ice diminishes.