"Chimpanzees...live in societies that are xenophobic, wandering in small parties, fighting with neighbours... In chimpanzee society, patriarchy rules. Communities persist through a line of father-son relationships. Males are the inheritors of territory. Males conduct the raids and the killing. Males are dominant. Males gain the spoils... Territorial gains, like territorial losses, have different impacts on males and females. For a male-bonded chimpanzee community, conquered lands can include not only a larger foraging area, but also new females who may simply continue to forage in the same area of forest as before the boundaries changed, only now with a different set of defenders. So males of an expanding community can gain females, which means that male chimpanzees should want to expand their territory to the largest area they can defend."