At a Glance

In March, scientists found a supercolony of penguins that went undetected for 2,800 years.Researchers were able to spot the population with help of an algorithm developed by a colleague at NASA.The team was then able to survey the colony and get a better idea of the population at its peak.

Earlier this year, scientists found a supercolony of 1.5 million Adélie penguins living on Antarctica's Danger Islands that had gone undetected for nearly 2,800 years. With the help of a colleague at NASA, scientists know how the massive population went undetected for so long and have an idea on how "super" their colony once was.

Researchers spent 10 months looking through every cloudless satellite image of Antarctica before implementing , according to their research published in the journal Nature.

"We thought that we knew where all the penguin colonies were," Stony Brook University ecologist Heather Lynch said at the American Geophysical Union conference.

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Once the algorithm took over, results quickly came back from the Danger Islands. Lynch said the team had "simply just missed" the detections — which were triggered by penguin droppings — and were able to see the extent of what they had overlooked when they went back and looked at the imagery more closely.

"We, I think, had missed it in part because we hadn't expected to find them there," said Lynch. The team had inspected one the islands in the group, but not all of them.

Imagery shows an Adélie penguin colony on Heroina Island, part of Antarctica's Danger Islands.

(Woods Hole Oceanographic Institution)

The Danger Islands aren't regularly surveyed since they're usually covered by a thick layer of ice, making them extremely difficult to reach. When they were first discovered in 1842, the British expedition that found the group of islands gave them their name because , according to Geographic.org.

Researchers made the trek to the islands to conduct a full survey — both on the ground and using drones — of the island's colony.

The team found the penguins react to humans much like they do across Antarctica. Typically, penguins don't like other beings that are taller than them out of their fear of skuas, a large bird that steals eggs from penguins' nests. But when the researchers sat, the birds ",” Lynch told TBR News.

Lynch's team suspected that the population was once even larger, and investigated further using satellite images dating as far back as 1982.

The late 1990s appeared to be when the super colony's population hit its peak and has declined ever since. The population's decline, Lynch said, "is not catastrophic" but has dropped some 10 to 20 percent.

By radiocarbon dating eggshells and bones found on the island, researchers were able to reveal that the colony was using the Danger Islands for some 2,800 years.

The islands' remote location and surrounding ice kept the population safe from krill fishing and interaction with mankind compared to other parts of Antarctica. Lynch said the decline in population is likely due to climate change, which is rapidly changing the Antarctic Peninsula.

"Now that we have discovered this hotspot of Adélie abundance here in the Danger Islands, we want to be able to protect it, and that involves trying to understand why the populations may have changed," said Lynch.