Satellites Spy Poop-Stained Ice, Revealing New Emperor Penguin Colonies

Researchers found eight new colonies, but all were small and located in parts of Antarctica predicted to be ravaged by climate change

Emperor penguins
Emperor penguins standing on sea ice at the Brunt ice shelf in Antarctica. British Antarctic Survey

Rusty-brown streaks of penguin poo seen from space have led to the discovery of eight new colonies of emperor penguin, reports Carolyn Gramling of Science News. Scientists with the British Antarctic Survey (BAS) spotted the tell-tale smears across Antarctica’s icy white by studying high-resolution satellite images, increasing the global tally of emperor penguin breeding sites by roughly 20 percent to a total of 61.

Sadly, the substantial increase in the number of breeding sites does not translate to a significant bump for the global population of emperor penguins. The new colonies were all small, only adding 5 to 10 percent to the global population of emperor penguins, which now stands at between 531,000 and 557,000.

Emperor penguin colony
Brown smears across the ice indicated the presence of an emperor penguin colony. European Space Agency / Copernicus Sentinel-2 Satellites

Emperor penguins may be the tallest and heaviest penguins on Earth, but counting them is hard. They live at the bottom of the world around Antarctica’s icy perimeter in some of the coldest and harshest conditions our planet has to offer, which makes in-person surveys extremely difficult. But having an accurate count of the flightless birds, which stand nearly four feet tall and weigh up to 88 pounds, is more important than ever because a mounting stack of research predicts the huge penguins will march toward extinction as climate change melts and rearranges the sea ice they depend on.

A 2019 study estimated that the world’s emperor penguins would decline by 81 percent by the end of the century if global greenhouse gas emissions continue to rise under a business-as-usual scenario. Even the increasingly unattainable best case scenario for climate change—an increase in global average temperatures of just 2.7 degrees Fahrenheit (1.5 degrees Celsius) relative to the preindustrial era—would entail a 31 percent decline.

Another sad caveat to the newly spotted colonies is that they are all located in spots predicted to be hit hardest by climate change.

“Whilst it’s good news that we’ve found these new colonies, the breeding sites are all in locations where recent model projections suggest emperors will decline,” Phil Trathan, the lead conservation biologist with the BAS, says in a statement. “Birds in these sites are therefore probably the ‘canaries in the coalmine’ – we need to watch these sites carefully as climate change will affect this region.”

Map of emperor penguin colonies
A map showing the locations of the known emperor penguin colonies. P.T. FRETWELL AND P.N. TRATHAN / REMOTE SENSING IN ECOLOGY AND CONSERVATION 2020

The new research, published this week in the journal Remote Sensing in Ecology and Conservation, relied on images taken by the European Space Agency's Copernicus Sentinel-2 satellites in 2016, 2018 and 2019, reports Yasemin Saplakoglu for Live Science. Brown pixels were what gave away the newfound colonies.

Yan Ropert-Coudert, a leading ecologist with the Scientific Committee on Antarctic Research who wasn’t involved in the new work, tells Frank Jordans of the Associated Press that using satellite imagery to track penguin colonies is a powerful tool, but noted that extensive ground surveys are also vital. Ropert-Coudert adds that accurate assessments of the emperor penguins’ numbers are essential to guide decisions aimed at ensuring the species’ survival.

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