Intracommunity coalitionary killing of an adult male chimpanzee at Ngogo, Kibale National

Intercommunity coalitionary killing of adult and adolescent males has been documented in two chimpanzee communities in the wild, and it was strongly suspected in a third. It may increase survivorship for the attackers, their mates, and their offspring by reducing the combined strength of hostile neighbors and/or by increasing territory size and food availability, and it may help the attackers to attract mates. Lethal coalitionary attacks by males on other male members of their own communities would not provide these benefits and are not expected, given the importance of cooperation among male commu-nity members in contests for dominance rank and in both defense and of-fense against neighboring males. Nevertheless, intracommunity coalitionary killings associated with struggles for alpha rank occur in the wild and in cap-tivity, and observers have seen serious gang attacks on maturing adolescent and young adult males at Mahale and Budongo: the victim in the Budongo case was killed (Fawcett and Muhumuza, 2000). I describe a lethal attack on a young adult male by a large coalition of males from his community at Ngogo