I would caution against the use of "murder" so loosely. Lions don't murder their prey. They kill their prey. Murder occurs when one entity with personhood intentional kills another entity with personhood, where personhood is rooted in the ability to comprehend reality (intellect) and the ability to make free choices among comprehended alternatives (free choice). "Murder" thus has a moral dimension that mere killing does not. Personhood is the seat of moral agency; without personhood, murder simply cannot take place, only killing, and it is a category error to ascribe moral goodness or evil to an act committed by a non-person. A spider eating another spider of the same species isn't murder; it may very well be the nature of that species to function that way.

(Entailed also by personhood is social nature. So, murdering another person is bad, because it is opposed to the very nature and thus good of the murderer. It's why killing in self-defense and the death penalty for murder are themselves mere killing, but not murder. Justice is served against the injustice of the gravely antisocial.)

From a game theoretic perspective w.r.t. just resources, murder does not generally pay especially given the social nature of a species given how antithetical it is to the social, but even if it does in some constrained sense, there is a greater intangible loss for those with personhood. Speak to almost anyone who has murdered someone. They will tell you that it changes them drastically, and not in a good way.