Researchers are tracking Adélie penguins in Antarctica using an unusual method – they developed an algorithm to track their guano, which is visible from space.

Yes, yes, we know, technically you can see anything from space with a good enough camera, but this is still a wonderful example to the current US administration of why utilizing NASA for Earth sciences and not just space is important.

Researchers have been using NASA’s Landsat satellites for the last 30 years to study Adélie penguin movements in the Antarctic and in the process have discovered dozens of new colonies, tracked population increases and declines, and written several published papers about their findings.

All of this feeds into an online database that monitors and follows the penguin populations. Using satellites means the researchers can view areas like the Danger Islands, which are rarely studied due to the sea ice cover making access to the islands difficult.

It was NASA scientist Mathew Schwaller who first came up with the idea in 1984 to follow the Adélie penguins using Landsat 5. His theory was that the penguins nest in large populations and where you have large groups of animals, you also have a large amount of guano – otherwise known as poop.  

Schwaller thought the guano stains might be large enough for the satellites to see, meaning a new way to essentially spy on the penguins and follow them to places not previously studied, and it turned out he was right.

Researchers at Stony Brook University, New York, who are also involved in the penguin database, developed an algorithm by sampling rocks at known colonies and then flagging up places on the satellite images of the Antarctic with the same color – guano-stained ice shows a pinker color than unstained surfaces – to find previously unknown colonies.

So far, they have been able to identify around 166,000 penguins on Brash Island, 23,000 on Earle Island, and 7,000 on Darwin Island that had not been previously recorded or accounted for.

The size of the pixels used in the Landsat satellites is the equivalent of 30 x 30 meters (100 x 100 feet), so it doesn't necessarily pick up small colonies. By comparing field observations and high-resolution commercial satellites with a view of 1 x 1 meter (3 x 3 feet) squares, they achieved a 50 percent success rate of identifying colonies with fewer than 3,000 breeding pairs. With colonies of around 10,000 pairs, the algorithm detected 97 percent of the penguins.

“We’re far from a point where satellites are going to make field work irrelevant. Instead, it has made fieldwork more efficient,” explained Heather Lynch of Stony Brook. “There is a nice synergy between satellite-based surveys and field surveys that I expect will be the status quo for a long time.”