Guano from penguin colonies is an archaeological treasure

Non-human primates are not the only animals whose past can be apprehended by the techniques developed by archaeology. Even when they do not use tools likely to withstand time, certain species can leave traces which are so many archives to be deciphered.

In the early 1990s, landing in Antarctica, Steven Emslie thus immediately struck by the mounds of pebbles amassed by Adélie penguins in abandoned colonies. “I have a background in archeology so I examined these mounds as an archaeologist would for a cultural site, says the researcher, now a professor of marine biology at the University of North Carolina (Wilmington). I wanted to know if they contained preserved bones and other tissue that could be analyzed over time, and it turned out to be correct. »

From there was born his project of “paleohistory of penguins”, which continues to this day – he returned a few days ago from a mission in Antarctica. The objective is to use various archaeological methods to describe the past of these animals and the evolution of the ecosystem in which they lived.

Steven Emslie has “applied these methods to dig into the mounds and recover organic remains, including penguin prey, fish bones, otoliths and squid ‘beaks’. [Il] do[t] appeal to radiocarbon dating to determine the history of past occupation by penguins”. “I am now using the tissues for stable isotope analyzes to assess diet and foraging locations in the past, particularly how these locations have changed with climate change”specifies the researcher, who is interested in two other species of penguins, the gentoo and the chinstrap penguin, also mummified in the middle of the guano by the Antarctic rigors.

Dietary change

The first to have had the prescience of the interest of these frozen natural archives was perhaps the Belgian meteorologist Louis Bernacchi. On February 17, 1899, as he prepared to take part in his first wintering on the Antarctic continent, he was struck by the thousands of corpses of young penguins killed by a cold snap on Cape Adare, at the entrance to the Ross Sea, which is still home to the largest colony of Adélie penguins. “Thousands of years from now, should this species become extinct, these frozen, debris-covered remains will be evidence of what once existed in these frozen regions”he wrote in his diary.

You have 50.84% ​​of this article left to read. The following is for subscribers only.