Rode and Audrey Hagen of Jackson Hole, Wyo., share a SoundClip with us. It's the sound of an elk bugle, an eerie sound that is a sure sign of autumn, when the animals enter rutting season. A new ...

In this animated video essay, "Sunday Morning" contributor Robert Krulwich and animator Nate Milton go inside one of Nature's mysteries, to examine why an adult male elk, weighing around half a ton, ...