I think I read something about some birds being able to sleep with only one hemisphere of their brain at a time, similar to dolphins. The common swift often spe

I think I read something about some birds being able to sleep with only one hemisphere of their brain at a time, similar to dolphins. The common swift often spends months at a time without touching ground. And lots of birds perform marvelous feats of long-range navigation, storks, for example, travel thousands of kilometers each year to return to their nest for breeding. They are amazing creatures.