You Can Find Emperor Penguin Colonies From Space by Their Poop

The satellites that first mapped emperor penguins could not see a single one of them. Landsat records the surface at 30 meters per pixel, and a four-foot bird disappears long before that. What those satellites could see was the mess. Emperor penguins spend the winter packed shoulder to shoulder on the sea ice, and they leave behind a reddish-brown smear of guano so large it registers from orbit as a stain on an otherwise blank white continent. Roughly half of the emperor penguin colonies we kno