Nature does not justify violence
That animals kill and eat other animals in nature does not justify us humans killing and eating other animals. Nor does it justify us not trying to humanely protect wild animals from being preyed upon.
The way we find nature to be is not a reliable source of ethics. We can look around at the ways animals in nature are and think critically about their relative goodness or badness, not just presume they are preferable since they are natural, or occur naturally. For example, I do not, because it exists naturally, assume predation to be the ideal. I can make a judgment about it taking into consideration how it directly harms sentient beings.