Animal migration has fascinated humans for millennia. And for good reason: Some of the most astonishing feats of endurance are performed by long-distance migrants, such as the nine-day non-stop flight ...

For the past few weeks, dozens of turkey vultures have been circling on thermals over my house in Oregon, preparing to soar away south into California. Not long ago, I saw a late monarch butterfly ...

Migrating animals have for a long time been tracked by recapturing tagged individuals. More recently, radio-telemetry, which requires an observer to physically follow the tagged animal, has been used.

When people think of migration, they often think of the animals in the world that travel huge distances. Some of these migrations are amazing. They involve thousands or millions of animals and are ...