Female Sexual Strategies in Chimpanzees R.M. Strumpf and C. Boesch Summary and presentation by: Aubrie DeBear, Neda Naimi & Cody Tyson Strumpf, R.M., Boesch, C. (2005). Does promiscuous mating preclude female choice? Female sexual strategies in chimpanzees (Pan troglodytes verus) of the Tai National Park, Cote d’Ivoire. Behav Ecol Sociobiol, 57,

Hypotheses Whether females express mate preferences Whether females are more selective at POP Whether female preferences differ inter- individually Influencing factors Strumpf, R.M., Boesch, C. (2005). Does promiscuous mating preclude female choice? Female sexual strategies in chimpanzees (Pan troglodytes verus) of the Tai National Park, Cote d’Ivoire. Behav Ecol Sociobiol, 57,

Results and Discussion Female rank and age Proceptivity rates in POP Eschewed males Non-preferred males Departing dominant male Most significant influencing factor Strumpf, R.M., Boesch, C. (2005). Does promiscuous mating preclude female choice? Female sexual strategies in chimpanzees (Pan troglodytes verus) of the Tai National Park, Cote d’Ivoire. Behav Ecol Sociobiol, 57,

Female Sexual Strategies More resisting of male solicitations during POP Increase mating with all males during Non- POP Graded signal hypothesis Mixed strategy Manipulation Strumpf, R.M., Boesch, C. (2005). Does promiscuous mating preclude female choice? Female sexual strategies in chimpanzees (Pan troglodytes verus) of the Tai National Park, Cote d’Ivoire. Behav Ecol Sociobiol, 57,

Critical Review Items: A – Interesting Points Promiscuity does not rule out selectivity, and in fact female chimpanzees may use both as a mixed strategy to attempt to influence which males will father their offspring (p. 519). Males are unaware of when a female is actually in POP, this means that they will not be sure of who sired the offspring. This hopefully leads to social support and less male aggression. The author indicated that female chimpanzees have a high proceptivity, or desire to reproduce, with males that were ascending in the social hierarchy at a fast pace. The fact that they have an ability to see this and predict it with great accuracy is fascinating. It was interesting to find out that both males and females initiate sexual interactions. This stood out because in the human population this is true as well showing a similar pattern. Strumpf, R.M., Boesch, C. (2005). Does promiscuous mating preclude female choice? Female sexual strategies in chimpanzees (Pan troglodytes verus) of the Tai National Park, Cote d’Ivoire. Behav Ecol Sociobiol, 57,

Critical Review Items: B – Weak or Unclear It was confusing that female chimpanzees had substantially higher proceptivity rates toward either the highest OR lowest ranking males during POP, excluding middle ranking males. This was just briefly mentioned, but not clearly explained. If females were more selective and choosy during POP, then why would they be just as proceptive to the lowest ranking males as highest ranking over the middle ranked males? The authors suggest that most pregnancies result from copulations between 1-3 days prior to ovulation and including ovulation. This was unclear because females engage in over one hundred copulations so how can they be sure which one led to pregnancy? With such a small sample size I wonder if the significant results could even really be representative of that species of primates as a whole. For example, a few outliers could have had a drastic effect. Strumpf, R.M., Boesch, C. (2005). Does promiscuous mating preclude female choice? Female sexual strategies in chimpanzees (Pan troglodytes verus) of the Tai National Park, Cote d’Ivoire. Behav Ecol Sociobiol, 57,

Video Female Mating Strategy &feature=related Strumpf, R.M., Boesch, C. (2005). Does promiscuous mating preclude female choice? Female sexual strategies in chimpanzees (Pan troglodytes verus) of the Tai National Park, Cote d’Ivoire. Behav Ecol Sociobiol, 57,