Episode Information

For birds, a brain that can function while literally half-asleep is important to survival. In flocks of birds at roost, those at the outer edge of the flock often have one eye open. Such birds are truly half-asleep: one brain hemisphere snoozes as the other remains awake and alert. The eye connected to the sleeping half of the brain closes; the eye of the wakeful hemisphere remains open and vigilant. Birds in the middle of the flock are resting the entire brain, sleeping with both eyes closed. Learn more—click link below.

This episode repeats at 8:58pm.