Emperor penguins reputedly have the highest feather density of any bird, with around 100 feathers per square inch of skin (15 per square centimeter). This “fact” crops up on Wikipedia and a host of other websites, and seems to trace to a statement made in a 2004 National Geographic news story.

It’s not true.

When Cassondra Williams from University of California, Irvine, first started looking into penguin feathers, she was shocked to see how many unsubstantiated statements there were, and not just on websites. Various scientific papers claimed that penguins had anywhere from 11 to 46 feathers per square centimetre, and none of them—none—described any methods or cited any sources behind these estimates. They might as well have come up with