Humans usually need up to eight hours of good sleep to have enough energy to start a fresh day. In cases where people are deprived of sleep, they can suffer grave and even fatal consequences. On the other hand, an elephant can live pretty well its life with just up to two hours of rest per day. Thus, scientists wanted to learn more about the elephant sleep and its secrets.
There are many elephants in captivity that scientists have no problem studying. However, these specimens usually lead different lifestyles compared to the wildlife. This is why scientists believe that they do not represent the cultural habits of the wild elephants. As a consequence, an international team of scientists from the United States, South Africa, and Botswana decided to follow the sleeping patterns of two matriarchs closely over the course of a month.
Their paper was published in the PLoS One on Wednesday. The authors were excited to announce that the study brings new insights into the mystery of the elephant sleep. They also noted that the captive elephants adopt different practices from their brothers and sisters in the wild. Thus, researchers had to attach monitors in the trumps of their two subjects. They also managed to track them down with GPS collars for 35 days. When their trumps stopped moving for five minutes, the scientists interpreted this as a sign that they were asleep.
The 30-year-old Matriarch was usually sleeping for an average of 2.3 hours a day. However, this period wasn’t continuous but grouped in smaller periods of rests that happened mostly but not exclusively at night. The second subject, a 37-year-old Matriarch slept for an average of 1.8 hours. There were days when elephants had no sleep. As for the tale that they sleep on their feet, it is true. Both of them are sleeping only 15.17% and 12% respectively in a recumbent position.
These findings are new from other studies of both captive and wild elephants. If these patterns of elephant sleep are true, it means that this is the mammal that rests for the shortest period of time in the world. The second and third places would be taken by horses who sleep an average of three hours per day and giraffes who rest for up to four hours a day.
While there is no clear reason for the short period of rest, researchers believe that this has to do with the large body that elephants have. Other agents could be environmental conditions, the risk of being attacked, and the need to eat plenty of food.
Image source: 1