The increased numbers of known populations is an encouraging sign about the penguin’s long-term survival chances.
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 new 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 just 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 this month in Scientific Reports.
After several years of preparation, a team of researchers traveled in 2015 to the Danger Islands near the Weddell Sea to do a more precise count on the nine-island archipelago. Using a drone doctored to work in the extreme climate of the region, 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).
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“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 on the landscape.”
Lynch said researchers had already 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.
“This area falls between two marine-protected areas that are being planned right now,” she said. And until this discovery, the Danger Islands “wasn’t considered a high priority for protection.”
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.
“We expect many of these species are going to be severely harmed and some already have,” said Boersma, noting that half the known population of Magellanic penguin chicks were wiped out in one storm. Continued government funding for satellites and other technology to track the animals is essential, she said.
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 penguins feed mostly on shrimplike krill, giving their guano the distinctive pinkish color that can be more easily seen from a satellite. The black-and-white animals tend to blend into the rocks and are harder to spot, she said.
There were plenty of challenges working in one of the coldest places on the planet, said Hanumant Singh, another study co-author. The batteries for the drones kept freezing and losing power, until the researchers began keeping them warm inside their jackets, said Singh, a professor in the Department of Electrical and Computer Engineering at Northeastern University in Boston. “If you warm them, they’ll keep flying,” he said.
They also had to manipulate the drones to operate at such a southern latitude, where the change in the Earth’s magnetic field close to the poles makes navigation more difficult, said Singh, who is also an associate scientist at the Woods Hole Oceanographic Institution, in Woods Hole, Massachusetts.
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 in recent years, she said.
Adélie are one of two penguin species that live on ice, and thus in some of the coldest places on Earth.
The biggest populations of Adélie penguins live in the Ross Sea, below and east of New Zealand.
While she remains anxious about the penguin’s long-term survival, Lynch said that finding new colonies is encouraging.
“Ecologists worry about having all your eggs in one basket,” she said. “We have a second basket now on opposite ends of the continent.”