I once sat at Smith’s Beach in the southwest of Western Australia and mused over this question. It was a lazy afternoon in the sun and I was happily watching dolphins surf the waves. Very relaxing! My natural curiosity began creeping into my previously idle thoughts. Do dolphins sleep? Do they dream? How? I had to Google. I needed the answer. More on this later.
I have always been fascinated with so many aspects of sleep, such as circadian rhythms or why we need to sleep, why some people need more than others, why we dream and how all of this affects our health. From my research and also from facilitating programs on sleep hygiene, I have learnt a lot about the subject. For instance, elephants stand in their deep (Delta) sleep but lie down in their REM (Rapid Eye Movement) cycle where dreaming occurs. Very likely a good thing too, if you have ever watched a dog sleep, you will have noticed they make a number of movements which look like they are dreaming about chasing something. Having something the size of an elephant running around while dreaming would most likely be very dangerous!
We still don’t definitively know the purpose of dreaming. It is hypothesised that it could be about ‘defragging’, like a computer, or perhaps simply processing events of importance.
We do know, from research however that an important part of sleep is to repair the cellular mechanisms of the body. We know that that sleep is an essential component in assisting the management of depression and other mental health issues. It is known that teenagers seem to need a lot of sleep and older adults require or want much less. Notable examples are Albert Einstein and Margaret Thatcher, who both reported to have required only 4 to 5 hours a night.
There are so many fascinating aspects to sleep. Fundamentally, we know that sleep is essential and that we need to be able to do it well. It is vital for our wellbeing, both physically and mentally. I will write more on how to achieve better sleep but for now, yes, dolphins, as mammals, do sleep. They cannot go into a full sleep, otherwise they would drown or be unaware of predators. They have learnt to let one part of their brain sleep at a time (www.dolphinear.com). Do they dream? I would like to think that they do….that they dream of surfing the waves, of turning beautiful and graceful somersaults as they play together. What a wonderful way to exist and dream!