What a lot of people do not realise is that in a true natural environment there is no such thing as old age.

Death comes quickly once a beast has past its prime and becomes more feeble.

In the National Geographic documentary "Eternal Enemies" detailing the "war" between hyaenas and lions, they claimed the most probable death of a lion is being torn apart by hyaenas.

So death by lion or death by hyaena. Equally cruel. But cruelty is a human concept and not a concept in nature.