Scientists Discover Hidden Supercolony of 1.5 Million Penguins

How do a million and a half penguins hide from human knowledge? They hang out on cold Antarctic Islands with the ominous and accurate name of "Danger Islands."

Scientists who study Adélie penguins noted that their populations were declining on the east side of the Antarctic Peninsula. But a new study, published in the journal Scientific Reports, documents a "supercolony" of Adélie penguins never counted before—hosting an astounding 751,527 breeding pairs of penguins, or over a million and a half individuals.

Quadcopter aerial imagery of an Adélie penguin breeding colony on Heroina Island, Danger Islands, Antarctica. Thomas Sayre McChord, Hanumant Singh, Northeastern University, © Woods Hole Oceanographic Institution

These penguins escaped notice until Michael Polito, an assistant professor in the department of oceanography and coastal sciences at Louisiana State University, stopped by on a cruise ship in 2006. The Danger Islands live up to their name: they are surrounded by treacherous sea ice and difficult to access. But the sea ice was low when he visited. When he saw penguin nests, he knew he had an important discovery on his hands.

It wasn't until he came back to count them with an international team of field scientists in 2015 that he realized the scope of the discovery.

Danger Islands Expedition Image (9)
Nesting Adélie penguins, Danger Islands, Antarctica. Michael Polito, © Louisiana State University

"We are all still kind of amazed," Polito, who is also a fellow at the Woods Hole Oceanographic Institute, told Newsweek. "We all knew there would be a lot penguins there, but I think none of us knew there would be this many." Polito and his team took a vessel to the island on a rare occasion when the sea ice was low, which meant the penguins were nesting there and not traveling.

Polito knew that counting the penguins by hand would be tedious and inaccurate, and he didn't think that the team would have enough time to do it. Instead, the researchers turned to technology. They brought a simple drone that Polito described as "off-the-shelf" and flew it around the islands on a preprogrammed course. "They would essentially mow the lawn, flying across these islands and taking pictures, and we knew we'd have all these images that we could stitch together," Polito explained. Then, a computer program counted the black dots, represented nesting pairs of penguins. The total came to more than a million and a half individuals.

An Adélie penguin and Quadcopter on Brash Island, Danger Islands, Antarctica. Rachael Herman, Louisiana State University, © Stony Brook University

Other populations of Adélie penguins are suffering as sea ice melts and temperatures increase. But these individuals on the western side of the peninsula are sheltered from some of the worst effects of climate change by the Waddell sea, a swirling, icy area that also makes it particularly difficult for humans to find them. From looking at older satellite and aerial imagery, the researchers determined that a similar amount of the islands had been covered with penguins in the 50s and 60s, meaning that their populations haven't been declining much, if at all.

Polito hopes that the discovery of these penguins will help policymakers better understand the importance of the Waddell sea, which is up for consideration as a protected marine sanctuary. "The timing of this research is really fortuitous because the marine protected areas were proposed before," he said. "But now we have the information to include this important population in that protection."

Penguins, take note: there's no need to hide.