People often talk about the wars between the Europeans and Native American tribes, and what an atrocity it was, but where there any atrocities committed between Native American tribes? What would they generally fight over and how often? Do we know how many native Americans died from these battles?
Just as a caution, but this sort of question usually comes up in the context of trying to minimize the impact of and justify actions of colonial powers against Native American groups with the logic that violence against people who were or are perpetrators of violence against other groups (at any point in the past) is less morally disagreeable than violence against "innocents" (however that is vaguely defined).
Basically, this sort of question is usually asked in order to prove a preexisting political position rather than trying to actually understand violence in the past, so don't be surprised if no one answers your question - they probably just don't want to open up that can of worms.