Oh, Poo

You can’t hide from satellites -- especially if you stain the ground with large patches of poo. Of course, it helps if the ground is the pure white snow and ice of Antarctica.

Scientists have used these brown stains to locate more than half of the colonies of emperor penguins. Because a colony can contain thousands of penguins, the patches of poo can be quite large.

Emperor penguins are the largest of all penguins. They stand about four feet tall, and can weigh 85 pounds. They live in colonies on sea ice around the coastline of Antarctica. Each colony spends about nine months of the year on the same patch of ice -- one reason they leave easy-to-see stains.

Before 2009, scientists had found only about 30 colonies. But that year, they started using satellites and airplanes to find patches of poo, known as guano. That almost doubled the number of known colonies.

And in 2020, they reported the discovery of eight more colonies. The scientists used images from a satellite that has higher-resolution cameras than earlier satellites. That allowed them to spot smaller patches of guano, which are produced by smaller colonies.

With those discoveries, scientists have cataloged 61 colonies of emperor penguins, with a total population of more than half a million. But if Earth’s climate keeps changing at its current pace, much of the ice they live on could vanish. That could slash the population by 80 percent by the end of the century -- a number that could scare the guano out of any penguin.