If you go to the zoo or the Australian outback any time soon you may be lucky enough to see a Koala. If you do I would bet a lot of money that he or she will be in a tree with eyes closed and looking pretty asleep. However, watch closely because the moment something moves near that Koala it will show alert behavior and be ready to move if it needs to. This has led many animal experts to reexamine their previous thoughts about Koalas. So do they actually sleep at all? Read on to find out what the experts think.
In the past, it was believed that Koalas slept for 18 – 22 hours. This was assumed through observational studies. If you quietly watch a Koala it will spend the majority of a day with its eyes closed, generally only opening them to eat or move. Experts now say this does not mean the Koala is asleep the whole time.
Rather the Koala is resting. Now I know what you are thinking, are we just being pedantic? What is the difference between rest and sleep? Well, there is a huge difference. Have you ever come home from a long day at work put on your favorite music and lay on the couch listening intently with your eyes closed. Or has your partner ever come home and lay his/her head on your lap, closed their eyes and told you all about their day? Of course, these are moments of rest and relaxation with eyes closed but definitely not sleep.
Experts now believe the same is true for Koalas. When observed in the wild they often close their eyes and remain still. Experts used to think they were sleeping but now are realizing that they are in fact resting. This is based on how alert they are and how they react in these moments. When you consider a Koala they rely on their nose and ears a lot more than their eyes (in comparison to humans) so they often close their eyes to focus on their surroundings and to get a little rest.
There are two main forms of sleep REM and NREM. REM can usually be easily observed as it is a deep sleep involving rapid eye movement and vivid dreams. No one has ever seen a Koala in a state of REM! While we are not suggesting that Koalas don’t sleep at all they certainly don’t sleep 20 hours a day either. If you are ever planning on sneaking up on a Koala with their eyes closed, be careful, they are probably fully aware you are coming!