“Predator” vs “extremely intelligant” is a wierd dicotomy to make. Many mammallian predators are extremely intelligant, such as most canids, large bears, and felids.

On the other hand, sleeping is an energy conservation strategy for many niches. Obligate carnivores tend to sleep a lot, because its the best thing to conserve energy if you aren’t activel hunting, ane the caloric payoff to a successful hunt is high enough that you don’t need to spend all your time doing it.

Many leaf-eating mammals also spend a lot of time sleeping, and have even evolved extreme energy conservation measures, such as sloths having a unique muscle fiber arrangement and reversed wrist tendons