Wildlife

Guano Stains Lead Researchers to Hidden ‘Supercolony’ of Penguins

The Danger Islands — a remote handful of rocks huddled among sheets of treacherous sea ice near the northern tip of the Antarctic Peninsula — are full of penguins.

Discovered on an expedition led by researchers at the Woods Hole Oceanographic Institution (WHOI), the unexpected penguin metropolis marks one of the single largest Adélie colonies in the world (they are native only to Antarctica), and disputes previous observations that the penguins have been steadily dwindling in numbers for the past 40 years.

While looking at NASA satellite imagery of the Danger Islands, researchers noticed significant guano stains on the rocks, pointing to the existence of some huge, unseen population of penguins. The researchers mounted an expedition in 2015 and, sure enough, encountered hundreds of thousands of Adélie penguins nesting in the rocky soil there.