Sleep

Working the night shift is no good, I know. You don't need me to tell you that. Unfortunately, all-nighters are part of life for many of us.

The struggle with sleep-anaemic mode of work is constantly playing havoc with our internal clock. Worse, should you read the neuroscientist Mathew Walker's book Why We Sleep, you will hear the bad news: the shorter your sleep, the shorter your life span.

One inside story of the book is how birds' sleep pattern can work out better than humans. So this is how birds get around sleep deprivation no matter how busy they are: they're able to sleep with just one side of the brain. One half of the brain rests; the other half stays awake. Then switch.

"Oh, it's fabulous," I heard myself in awe, casting my eyes heavenward. To me it sounds like a genius way of sleep. But wait. Sleeping with half brain off and half brain on isn't a perfect solution, however, and that would still have myriad risks. Split-brain attention can be susceptible to the threats of predators, say. As an analogy, imagine your tummy being cut open and operated by a surgeon with one side of the brain sleeping. It is anything but safe.

How, then, could birds get nighttime benefits and yet maintain safe sleep?

As Matthew Walker tells in his book, many species of birds have an even more ingenious answer when they group together. The flock simply line up in a row. Except the birds at each end of the line, the rest of the group will allow both halves of the brain to indulge in sleep. Charged with the core duty of sentinel birds, those at the far left and right ends of the row are supposed to give alarm-call in case of predators - it's no wonder they can't fall asleep completely. They will enter deep sleep with just one half of the brain (opposing in each), leaving the corresponding left and right eye of each bird wide open. In doing so, the "anchorbirds" provide full panoramic threat detection for the entire group, maximizing the total number of brain halves that can sleep within the flock. At some point, the two anchorbirds will stand up, rotate 180 degrees, and sit back down, allowing the other side of their respective brains to enjoy periods of slumber.

The more I think about the eye-opening lesson from the birds, the more I am convinced of the tried-and-true strategy of survival: teamwork.