Survival Theory?!

[supersunshinex3]

Hi guys! Could somebody please clarify the survival theory of sleep for me?
 
It states that sleep enhances survival by making an animal inactive (and thus, hidden from it's predators) yet the Macmillan book says that predators sleep a lot. But if predators are not in danger, why do they need to sleep so much?!

So confused

[Camo]

Predators sleep more because they are more protected, and do not need to worry bout other animals attacking them while they sleep. Animals of prey are shown to have shorter amounts of sleep due to the survival theory. It confuses me to but thats the best way to explain it.

[diem]

I believe that is a limitation of the survival theory =P

The survival theory proposes that we sleep because we are vulnerable at night (can't see in the dark) hence we protect ourselves by hiding away from predators to increase our chance of survival.

Support for this theory: Animals with fewer predators (such as lions) or animals that can hide away (possums, can't think of any other animals) sleep longer hours than those large animals that have many predators (such as horses)

Limitation for this theory: You are subject to greater vulnerability when you are sleeping because you are less aware of what is happening in the environment.

Hope I clarified some things for you =]

[Camo]

Support for this theory comes from comparative research of different animal species. Animals that have few natural predators, such as bears and lions, often sleep between 12 to 15 hours each day. On the other hand, animals that have many natural predators have only short periods of sleep, usually getting no more than 4 or 5 hours of sleep each day.

*Use of some animals*