Elephant All-Nighters? Giant Beasts Sleep Only 2 Hours

A sample size of two is small, but if the two matriarchs are representative of their species, African elephants may be the shortest-sleeping mammals on Earth, the researchers said. "Elephants really don't sleep all that much, and this appears to be related to their large size," said study lead researcher Paul Manger, a professor in the School of Anatomical Sciences at the University of the Witwatersrand in South Africa. Previous studies have described elephant sleep, but many of those studies have flaws — either using captive elephants, which have different sleep schedules than wild elephants, or failing to consistently distinguish between rest and sleep, Manger said.