Fatal attack on an infant by an adult female tonkean macaque

We describe a fatal attack on a 10-month-old female infant by an adult female Tonkean macaque (Macaca tonkeana)in a semi-free-ranging group. During an intense conflict involving many group members, an adult female, the second most dominant in the group, attacked the infant of a lower-ranking female. The attacker remained near the victim for approximately 20 min, grabbing and biting it repeatedly, until the mother retrieved the infant. She died 2 days later. An autopsy revealed no lethal injury;the main cause of death was starvation or dehydration or both. We discuss social conditions under which a fatal attack by an adult female might occur.