Even more astonishing for the researchers is that the penguins' colony on the Danger Islands is formed of approximately 750,000 families (breeding pairs) of Adelie penguins, which represent a lot more than all the Antarctic Peninsula Adelie families. That translates to about 1.5 million Adélie penguins, or roughly 20% of the total population of penguins in Antarctica. And how do you find 1.5 million penguins?
In 2014, Lynch and her colleagues spotted penguin poo on Nasa satellite imagery of the islands, so launched an expedition in December 2015. "Finally getting into the Danger Islands and counting the penguins shows how robust populations are where the ice is intact".
Even more interesting, scientists think the penguins have flourished on the Danger Islands for decades, while other colonies of the birds have declined on other parts of the continent, especially on its western half.
'Until recently, the Danger Islands weren't known to be an important penguin habitat, ' said Heather Lynch, associate professor of ecology and evolution at Stony Brook University. "But with only two hours on land it was impossible to estimate the size of the population before sea ice conditions forced us to leave", Polito said.
The data seemed to suggest that there were hundreds of thousands of penguins living on this islands, which Lynch initially thought "was a mistake". Once they made it to the island, they sent out fleets of drones to capture a detailed set of high-resolution images that they could stitch, mosaic-like, into a much more complete and telling image. It puts the East Antarctic Peninsula in stark contrast to the Adélie and chinstrap penguin declines that we are seeing on the West Antarctic Peninsula. "We want to understand why", said Stephanie Jenouvrier, a seabird ecologist at WHOI and coauthor of the study, in the release. "But it also reinforces the urgency to protect Antarctic waters from the dual threats of overfishing and climate change". "Food availability? That's something we don't know", she says. Logistical support was provided by Golden Fleece Expeditions and Quark Expeditions. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the oceans and their interaction with the Earth as a whole, and to communicate a basic understanding of the oceans' role in the changing global environment.