This is epic. I had little, well to be honest NO, idea has to how whales slept. I always assumed they were similar in physiological terms to dolphins, which I believe have half their brain (one hemisphere) sleep at a time whilst the other half is awake. However, this photo, and some articles and videos I just looked up, shows a pod of sperm whales in deep sleep whilst floating vertically just under the water surface.
It seems that scientists only first learned of this, and documented it, back in 2008 in the waters off of northern Chile.
For scientists have filmed whales drifting off to sleep for the first time.
A pod of six sperm whales was captured on film floating motionlessly and upright just below the surface of the sea off the coast of northern Chile.
The footage confirmed data evidence from 59 tagged sperm whales around the world that they snatch brief periods of sleep lasting about 12 minutes at a time during their ocean voyages.
Here is the footage the scientists captured.
“Many mammals show species-typical sleeping behaviour, such as dogs circling before lying down, lending support to the idea that sperm whales sleep during these drift dives.
“One exciting aspect of this finding is that it suggests that they actually might sleep in a fashion that we recognise as similar to sleep in terrestrial mammals. The sperm whale behaviour we describe seems to allow normal-looking quiescent sleep, possibly including REM sleep which has never been clearly observed in any cetacean. “
It also raises the possibility that the sperm whale – the largest toothed whale which can be 60-feet in length and which has the largest brain of all whales – may also be capable of dreaming.
Dr Patrick Miller of the University of St Andrew’s School of Biology’s Sea Mammal Research Unit
This research shows that sperm whales may completely ‘switch off’ for short lengths of time in the wild, effectively having ‘cat naps’ whilst they perform slow rhythmic dives. The research team think this study shows that sperm whales could require less sleep than other wild mammals.