A new colony of Adélie penguins has been discovered near Antarctica, substantially increasing the known populations of the knee-high creatures.
“It’s always good news when you find new penguins,” said P. Dee Boersma, director of the Center for Ecosystem Sentinels at the University of Washington, who was not involved in the study. “The trends have not been good for so many of these species.”
Previous censuses of penguins had come close to these animals, living on the Danger Islands off the end of the “thumb” of Antarctica, below South America. But satellite images of the islands revealed the pinkish-red stain of penguin guano, suggesting larger colonies than expected, said Heather Lynch, one of the five primary investigators on the new study, published Friday in Scientific Reports.
After years of preparation, a team of researchers traveled in 2015 to the Danger Islands to do a more precise count on the nine-island archipelago. Using a drone doctored to work in the extreme climate, the researchers were able to get a precise estimate of the numbers of breeding pairs of Adélie penguins in the region: about 750,000 (or 1.5 million individuals).
“The drone imagery is of a quality that just blows everything else away,” said Lynch, a quantitative ecologist at Stony Brook University. “You can see each penguin.”
Lynch said researchers had known about a population on Heroina Island, at the northeast end of the Danger Islands chain. Now they’ve found that sizable populations live on other islands near Heroina. “These new colonies totally change our appreciation of the Danger Islands as a penguin hot spot,” she said.
The greater numbers will help ensure that conservation efforts focus on keeping them safe, she said. Until this discovery, the Danger Islands “wasn’t considered a high priority for protection,” she said.
Boersma, who also is a co-chairwoman of the Penguin Specialist Group for the International Union for Conservation of Nature, agreed that finding penguins in some of the more remote spots on Earth is crucial. Now, she said, researchers need to watch them over time to track how they’re faring.
One of the surprises of the study, Lynch said, was that the Danger Islands penguins don’t nest in a circular pattern, as would be expected, to provide the best protection from predators. Instead, they seem to be faithful to individual nesting spots, prizing habit over safety, she said.
The Adélie are not recent migrants to the Danger Islands. Photos taken in 1957 by seaplane show colony boundaries in virtually the same locations — now that researchers know what they’re looking for.
The discovery of so many new animals has raised questions about how they’re finding enough food. “What it is about the ocean right in that region that makes it so productive, is something we’d like to figure out,” Lynch said.
The global Adélie penguin population now numbers about 4 million pairs and has nearly doubled over the past four decades, for unknown reasons, Lynch said. But the population along the Western Antarctic Peninsula — one of the most rapidly warming places on the planet — has dropped substantially, she said.
Adélie are one of two penguin species that live on ice, and thus in some of the coldest places on Earth. “Ecologists worry about having all your eggs in one basket,” Lynch said. “We have a second basket now on opposite ends of the continent.”