A team from the University of Witwatersrand recently conducted a study on the sleeping habits of wild elephants.
Elephants in captivity sleep for an average of six hours per day, but Prof. Paul Manger, and expert on animal sleeping habits, has long suspected that this may not be the case.
So a few animals were tranquilised and fitted with fitness trackers to see how much sleep wild elephants actually get. The study was first published in Plos One.
These fitness trackers recorded when the elephants came to a complete stop and these intervals between walking was interpreted as sleep.
The result were quite surprising. The elephants only slept for around two hours while standing, and only lay down for some R&R once every three or four days.
If a threat was detected nearby, the elephants would stay awake for two solid days.
According to the scientists, this study goes against what we understand around REM sleep, as the brain stores memories during this phase of sleep.
As elephants are known to have long-term memories, what we currently know about REM sleep in animals and long term memory just doesn’t add up.