The study was quite the sensation when it was published in March of 2017. Scientists affiliated with University of the Witwatersrand in South Africa tracked African elephants in the wilds of Botswana for a month straight, and found that they only slept for two hours per day on average! What’s more, the animals could skip a night’s sleep without needing extra naps the next day. Huh? How? Could we learn to sleep like that? Alas, elephants’ amazingly efficient sleep schedule is likely unique to them, not something humans could adopt through scientific means.
The study further evinced a trend that extends across the mammalian class: the bigger the mammal, the less sleep it needs. Some of the tiniest bats routinely sleep 18 hours a day. Cats sleep between 12 and 16. Chimpanzees doze about 10 hours. Cows snooze for about four. Yes, there are exceptions here and there – prey animals sleep less, predators more – but the trend is pretty consistent.
