The discovery strengthens the case for protecting the waters around the Antarctic Peninsula.
Off the coast of western Antarctica, a tiny archipelago called the Danger Islands has been home to more than 1.5 million Adélie penguins that were hiding in plain sight.
The islands were long known to have penguins, but how many remained a mystery until satellite images and an on-the-ground survey revealed the colonies’ immense sizes.
The new counts include the third and fourth largest colonies of Adélie penguins in the world; in all, they increase the region’s known penguin abundance by nearly 70 percent.
The findings, published in Scientific Reports on Friday, are helping inform plans for conserving Antarctica’s waters, some of which have seen alarming declines of Adélie penguins. They also highlight how researchers can combine in-person and satellite data as never before.
“The combination of several different image datasets is what made this paper stand out for me,” says Luba Reshitnyk, a marine geographer at the Hakai Institute who wasn’t involved with the study. “Mapping penguins (or more accurately, their habitat) from space is very exciting!”