Linda M. Fedigan

Infanticides during Periods of Social Stability: Kinship, Resumption of Ovarian Cycling, and Mating Access in White-Faced Capuchins (Cebus capucinus)

In non-human primates, most infanticide cases (85%) occur during periods of social instability when a changeover of the top-ranking male occurs (van Schaik, 2000). In contrast, infanticides during periods of social stability have only been reported for a few species (Valderrama et al., 1990; Murray et al., 2007; Gibson et al., 2008). The sexually selected infanticide (SSI) hypothesis (Hrdy 1974, 1979), proposes that infanticide is a male reproductive strategy in that males adopting this strategy benefit by gaining mating access to females who resume ovarian cycling prematurely following the death of their unweaned offspring. According the SSI hypothesis, infanticide is a male reproductive strategy if: 1) the attacker is unrelated to the infant, 2) the mother’s time to conception is shortened by the infant’s death, and 3) the infanticidal male has an increased probability of siring the mother’s future offspring. Though other hypotheses have been suggested to explain infanticide, most reported cases occur during or after periods of social instability and thus appear to fit the SSI hypothesis (Hrdy 1974, 1979; van Schaik, 2000).