Wild African Elephants Are Insomniac: Study Reveals They Only Need Naps Regardless of Activity
A research conducted by the UCLA Center for Sleep Research and the nonprofit research group Elephants Without Borders revealed that wild African elephants (Loxodonta Africana) do not need much sleep in a day.
For the study, the team observed two female wild African elephants in Chobe National Park in northern Botswana for a month. Their movements were tracked using "actiwatches," a device attached to their trunks.
As explained by The Atlantis, the trunk is their most mobile appendage. It usually remains moving and is rarely inactive when elephants are awake. For reasons that are still unclear, typically, smaller-bodied mammals sleep for longer than larger ones. This is proven by the results of the study.
After analyzing the data gathered, it was revealed that at an average, these giants only sleep for two hours a day -- the lowest duration for any land mammal, thus far recorded. The researchers wrote in their paper published in PLOS One notes that the elephants had a polyphasic sleep, meaning the two hours of sleep did not occur in a single slumber, rather in short naps.
What is even more remarkable is that on five occasions, the elephants observed managed to stay up for 46 hours straight despite traveling nearly 19 miles in 10 hours.
In addition to the "Actiwatches," the elephants were also attached with a gyroscope, to determine the sleeping positions of the elephants. Based on the results, each elephant slept lying down on only 10 of the 35 days, which means they have little rapid-eye-movement (REM) sleep. Thus, infrequent dreaming.
The results put into question what many scientists currently believe in -- that REM when animals dream is vital to memory consolidation. "It seems like elephants only dream every three to four days. Given the well-known memory of the elephant this calls into question theories associating REM sleep with memory consolidation," lead author, Paul Manger of the University of the Witwatersrand, South Africa told BBC.
Manger's team's study marks the first time free-roaming elephants have been studied to measure sleep quantity and patterns of elephants. As explained by Manger, it is only when any animal is studied in the wild that we could truly understand their nature and evolution.