Poop Stains Lead Researchers to Hidden Supercolony of 1.5 Million Penguins

September 29, 2018

Adventurers beware, the Danger Archipelago, a few isolated rocks squeezed into the treacherous sea ice near the northern tip of the Antarctic Peninsula, is teeming with penguins. One might not imagine that penguins themselves are dangerous, but then again, one might never have seen (or smelled) 1.5 million penguins breeding at the same time. According to a new paper published today (March 2) in the journal Scientific Reports, a previously unknown “supercolony” of nesting Adelie penguins has recently been discovered in the rarely studied Danger Islands.

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

“Not only do the Danger Islands have the largest population of Adélie penguins on the Antarctic Peninsula, they also do not appear to have suffered the population declines associated with recent climate change found along the western side of the Antarctic Peninsula,” study co-author Michael Polito, an assistant professor at Louisiana State University, said in a statement.

The team’s discovery, like many great discoveries, began with bird droppings, or seabird droppings.

While looking at NASA’s satellite images of the Dangerous Islands, the researchers noticed visible guano stains on the rocks, suggesting the presence of some huge, unseen penguin populations. The researchers conducted an expedition in 2015 and, sure enough, encountered hundreds of thousands of Adelie penguins nesting in the rocky soil there.

Using a combination of manual counting, drone photography and a neural network counting program, the researchers analyzed a large number of synthetic photos of the island to pick out penguin nests from the surrounding landscape and count the penguin population. The team’s final tally was 751,527 pairs of penguins – or just over 1.5 million birds.

The new study notes that the unexpected discovery of the penguin colony is optimistic news for scientists who have observed a steady decline in Antarctica’s Adélie penguin population over the past 40 years. However, the colony’s presence on such a remote island provides more questions than answers.

“The population of Adelies on the eastern side of the Antarctic Peninsula is different from what we see on the western side,” study co-author Stephanie Jenouvrier, a seabird ecologist at WHOI, said in a statement.” Is this related to the extended sea ice conditions there? Food availability? That’s something we don’t know.”

What researchers do know at least is that there is one more reason (or rather, 1,500,000 more reasons) to classify the waters around the Antarctic Peninsula as a marine protected area (MPA) – an area where human activities are legally restricted for conservation purposes. The International Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) is currently considering a proposal to recognize hazardous island areas as MPAs.