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The documented global population of Adélie penguins just grew by 20 per cent.

A colony of 1.5 million of the creatures has recently been discovered in a remote region of Antarctica called the Danger Islands, according to new research published in the journal Nature.

"It's kind of amazing that there's been this really large number of penguins breeding on these small islands in a remote part of Antarctica that sort of slipped under the radar for so long," co-author Michael Polito, an oceanography professor at Louisiana State University, told As It Happens host Carol Off.

"It's exciting because it's a very significant number from a global population standpoint."

Adélie penguins jump off an iceberg in the Danger Islands region of Antarctica, where the population has remained stable for decades. (Rachael Herman/ Stony Brook University, Louisiana State University)

Polito got wind of the colony in 2006 during a brief exhibition.

"I only had a couple hours on the island, and it was late in the breeding season so there wasn't many adults on land — but there was lots and lots of poop," he said.

"And so you could tell that there had to be a lot of penguins on this island."

The Louisiana researchers took the discovery to colleagues at Stony Brook University, who conducted a detailed analysis of satellite imagery in the region.

"I thought, holy cow, there are not only colonies, but huge colonies," co-author Heather Lynch, a Stony Brook ecology professor, said in a press release.

"How did we miss this really obvious thing?"

Danger Islands expedition team members on Heroina Island, Danger Islands, Antarctica. (Alex Borowicz/Stony Brook University)

So a team of researchers headed out on another expedition to the islands in 2015.

There, using drone footage, they counted 751,527 nests. At two penguins per average nest, that's a whopping 1,503,054 previously undiscovered birds — 20 per cent of the creature's known global population.

That's promising news for a species whose numbers have been steadily declining over four decades amid rising temperatures and melting sea ice on the western side of the Antarctic peninsula.

What's more, the number of penguins on the Danger Islands — which are farther north and closer to the icy Weddell Sea — appear to have remained stable over the decades.

"It validates our previous understanding, or at least our previous idea, of how Adélie penguins are affected by climate change," Polito said.

Still, he added, the penguins aren't out of the woods just yet.

"If we look at the future projections of climate change and the pace of climate change, even areas like the Danger Islands have the potential to be negatively affected," he said.

"So I think this is exciting and good news for now but, of course, we have to look to the future."