The Secret World of Animal Sleep:Asleep on the Wing

  • 3m
  • 4K
  • TV-G

When birds need sleep, they do it on the fly--quite literally. They're able to enter a special kind of half-sleep state that lets them rest midair, which is especially important if you're a migratory bird, like the Alpine swift, clocking thousands of miles at a time. Glide into the astounding world of avian sleep.