Scientists have recently discovered new knowledge on how elephants sleep. Although elephants in zoos sleep an average of about 6 hours a day, in the wild they may only sleep 2 hours a day, usually during the nighttime. For this study, the research team tracked two elephants in Botswana and fitted them with fitness trackers under the skin of the animals' trunks. If the elephants stayed still for more than five minutes, the device would record that the elephants were sleeping. The two elephants were also fitted with a gyroscope to assess their sleeping position.
The team determined that both matriarchs in the study sometimes stayed awake for several days without sleeping. Usually during this time, they were traveling and only went into rapid eye movement (REM) every three or four days, when they slept lying down rather than on their feet.
Professor Paul Manger of the University of the Witwatersrand, South Africa said, "We had the idea that elephants should be the shortest sleeping mammal because they're the largest. Why this occurs, we're not really sure. Sleep is one of those really unusual mysteries of biology, that along with eating and reproduction, it's one of the biological imperatives. We must sleep to survive."
