In the rapidly warming Antarctic, two species of penguins are in dramatic decline.

That’s the news out of a new study published by Oceanites, a nonprofit organization that closely monitors penguins and other Antarctic seabirds, in collaboration with researchers from NASA and Stony Brook University in New York.

Relying on satellite photos and on-the-ground analysis from more than 660 sites across the frozen continent, the study paints a broad picture of the health of several Antarctic penguin species: the Adélie, chinstrap, emperor, and gentoo. Like endangered polar bears, penguins have come to represent vulnerability in the face of rapidly unfolding climate change.

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The report looked specifically at the Antarctic Peninsula, which has warmed by a year-round average of 5 degrees Fahrenheit in the past 60 years.

There, two species — Adélie and chinstrap penguins — were reported to be in severe decline. Meanwhile, gentoo penguins appeared to be adapting to changing circumstances.

A gentoo penguin sliding in the snow in Antarctica. Oceanites/Ron Naveen

“In one generation, I have personally witnessed the precipitous decline of once abundant Adélie and chinstrap penguin populations,” Oceanites founder and president Ron Naveen said in a statement. “These iconic birds are literally canaries in the coal mine. They provide critical insights into the dramatic changes taking place in the Antarctic.”

The researchers theorize that gentoo, Adélie and chinstrap penguins might be adapting differently to changes in their food supplies. Left without the same supplies of krill, a small crustacean, gentoo penguins appear to be supplementing their diet by eating more fish. Adélie and chinstrap penguins, however, do not demonstrate the same behaviors.

An Adélie penguin in Antarctica. Oceanites/Ron Naveen

Researchers also pointed to the collapse of sea ice, which penguins require to hunt from, as a root cause for the declining numbers.

The Adélie penguin appears healthier in other parts of the Antarctic that have not experienced such significant changes from rising temperatures, like East Antarctica and the Ross Sea, researchers said.

Global warming is transforming Antarctica, one of the most remote places on Earth, as sea ice melts, leaving more open water than ever before.

Antarctica’s ice shelves — the powerful structures that act as buffers preventing glaciers and ice streams from spilling out into the sea — are also in decline. Antarctica’s Larsen-A and Larsen-B ice shelves have already collapsed, and new satellite images show massive cracks in the Larsen-C ice shelf.

And of course, it’s not just a problem of the southern hemisphere. Last year, NASA described the melting ice in the Arctic as the “new normal.”