Penguin colony benefits from climate change

Adélie penguins could be among other ‘climate change winners.’

by Rebecca Harrington

While climate change has negatively affected polar bears up north, some penguins down south may actually be benefiting.

University of Minnesota research published online Wednesday found an Adélie penguin colony population grew by 84 percent over the past half century. Since the 1980s, the average summer temperature in the area has increased by about 1.5 degrees Celsius.

The finding was unique to the colony studied but could be happening in other colonies and species, said Michelle LaRue, co-author of the study and a research fellow at the College of Science and Engineering’s Polar Geospatial Center.

“This particular colony is a climate change winner,” she said. “It’s not necessarily that all these other penguins … are going to be responding this way. Perhaps this is happening elsewhere and we’re just not aware of it yet.”

Adélie penguins are 1.5 to 2.5 feet tall and weigh around 11 pounds. While the birds need land to breed, LaRue said Adélie penguins need sea ice to eat krill and silverfish. But, the land needs to be ice-free for them to be able to breed.

Sea ice gets incredibly thick in Antarctic winters. Since this particular penguin population was bound by water on two sides and a cliff on another, LaRue said melting glaciers benefited them because it gave them more breeding habitat area.

Worldwide, studies estimate the sea ice at the warmest time of year is currently half of what it was in 1979, according to the National Snow and Ice Data Center. Sea ice is important in keeping the temperature of the earth down because it reflects nearly all of the sunlight that hits it.

The researchers used aerial photography — taken by the Army and the U.S. Geological Survey throughout the 20th century — and modern satellite imagery to measure the change in the colony’s habitat and population size on Beaufort Island, which is about 200 miles west of the international date line.

Matt Swanson, a co-author and University graduate student, worked on matching up the photos from over the years at the center’s Minneapolis location. Their findings, he said, are just “one piece of a big puzzle.”

“You have a big process going on,” he said, “and you’re going to see different things happening at smaller scales. Some may support what you think and some may not. You have to take them all into consideration.”

Since 1958, the colony’s habitat size nearly doubled. The colony had almost 35,000 breeding pairs 30 years ago, compared to almost 64,000 in 2010, when the last data was taken.

Other species, like Emperor penguins, are not faring as well as the Adélie penguins, LaRue said, because the larger birds need sea ice for breeding habitat, and it’s melting.

“[But] climate change isn’t necessarily going to be bad for all species,” she said. “Even outside of Antarctica, there’s going to be climate change winners.”