This Hummingbird's Tail Whistles, and No One's Sure Why
In early spring, people walking through the deserts of California might be able to hear a high-pitched whistle. That noise comes from a male Costa’s hummingbird, but not from his throat—it’s all in his tail.
Males woo females in a number of ways. They sing. They spread the iridescent feathers of their throats, transforming their heads into shiny, violet octopuses. And they fly up to tall perches to plummet into acrobatic dives, careening downward before pulling up at the last second. When they hit a critical speed, the back edges of their outermost tail feathers start to flutter. That’s the source of the whistle.
likens that whistle to the Stuka dive bombers that Germany deployed in World War II. As these that will be instantly familiar to anyone who’s watched old war movies. The Stuka’s wail was intended to weaken morale and intimidate the enemy. The Costa’s hummingbird’s whistle, by contrast, is intended to attract a mate.
