Survival theory of sleep

[oliverk94]

Hey guys. I've been reading into the survival theory of sleep.. I understand that the survival theory of sleep proposes that sleep evolved as a way of increasing survival by making the organism inactive during the part of the during where it was risky or dangerous to move about.. but one of the evidences that the Grivas book shows for this is:

'Lions, zebra, cows and buffalo sleep as much as 15 hours a day'

I don't really see how lions have to sleep for that long period of time since they don't have that many predators.. wouldn't it be more in accordance with the theory that they sleep less since they don't have that much risk when awake?

Could someone please explain this?

[happycat]

Hmmm... interesting maybe the lions are asleep when the hyaenas are active? Hyaenas can do lions damage so they can be a threat to lions. Just an educated guess but I dunno much about hyaenas.

[sandi]

Lions, tigers and gorillas would sleep for 15 hours a day because they wouldn't need to be awake or alert to watch out for predators because they don't have an abundance of predators

While the horses, zebras, cows and buffaloes would need to stay awake and alert for most of the day to watch out for potential predators.

Hope that helped:-)