In January 2016, Steven Emslie completed a penguin colony study season near Zucchelli Station, an Italian base in Antarctica. When the Australian summer quickly came to an end and all the planned work was done, Dr. Emslie, an ornithologist at the University of North Carolina, Wilmington, what any good scientist would do with a few extra days in Antarctica: He went exploring.
He had heard rumors of penguin guano on a rocky cloak along the Scott coast, but knew of no active colonies there. Curious, he arranged a helicopter flight into the area and looked around.
“Since Robert Falcon Scott and Ernest Shackleton explored the area over a hundred years ago and hadn’t written about penguins at this point, I wasn’t expecting much because they always wrote about penguins when they saw them.” he said.
And yet, Dr. Emslie immediately that he had found something interesting upon arrival. “There were pebbles everywhere,” he recalled.
While pebbles are a common find on other continents, they are rarely found in abundance on arid land in Antarctica. The Adélie penguin colonies are an important exception, as the birds collect the small stones from the beaches to build their nests.
The pebbles had been grouped into nests and had recently been scattered somewhat by the weather. Then Dr. Emslie the guano. There was lots of dried penguin litter that left iconic white spots on the nearby rocks. Then he found the corpses of the penguins.
Dr. Emslie was stunned as the feathers were still intact and the meat had barely decayed.
“I remember thinking, wow, a penguin colony that even Shackleton didn’t know about,” he said.
The shock aroused further curiosity and made him wonder what might have happened to the colony. Intrigued, he collected some remains and took them back for carbon dating analysis to find out when the birds had died.
With death dates between 800 and 5,000 years ago, Dr. Emslie immediately that guano, feathers, bones, and pebbles had been trapped under layers of ice for centuries, and that it was indeed the “freshly dead” penguins that were recently thawed mummies that had long ago been swallowed by advancing snowfields. Scott and Shackleton could be forgiven for not discovering this colony as it was completely hidden when the explorers were in the area.
The find paints a picture of a place where the occupation of Adélie penguins ended abruptly about 800 years ago after over thousands of years at regular intervals.
Dr. Emslie speculates in Geology magazine. There he reported in mid-September about his findings that the cooling temperatures formed a kind of sea ice along the coast that lasted into the summer months. This sea ice, known as “fast ice” because it is “attached” to the coast, makes it very difficult for penguins to gain access to beaches and prevents them from colonizing places where it occurs.
He said he thought the ice was forcing the colony to be abandoned, but also suggested that warming temperatures could change things for years to come.
As the Antarctic ice melts and sea levels rise, established penguin colonies must disperse to new locations. Dr. Emslie suggests that the penguins could then return to places like this one.
“They need pebbles for their nests, so any pebbles that are already in the country in this place will be very attractive,” he said. “I wouldn’t be surprised if you made this place your home again in the near future.”
Other penguin experts agree.
“We always thought that Adélie penguins had a strong impetus to return to the nesting sites where they were born year after year, but as several catastrophic ice bursts recently showed us, they are actually quite adaptable,” said David Ainley, one Penguin Ecologist at HT Harvey & Associates, an environmental consultancy.
“We have seen Adélies roam the coast in small herds and when they find a promising looking place like this they will make it their home,” he said.