Researchers have documented prolonged warfare between groups, and even one case of ‘genocidal’ activity in which one troop systematically slaughtered most members of a neighbouring band.
I am skeptical about the use of the term “warfare” here, which implies some sort of strategical conflict. Almost all animals will fight and kill to protect their precious resources — even members of their own species who threaten their survival. But I am not convinced any other species has the cognitive ability necessary to conduct war and genocide. To me, these terms imply some sort of forethought.
