Unformatted text preview: • females with infants copulate (‘pseudo-estrus’) • females do not try to leave (more than 1-2 days) - repelled by other groups perhaps dispersal --> infanticide in new group? Multiple-mating and the associated long estrus of females = anti-infanticide strategy via paternity confusion? Chimpanzee swelling cycle
Chimpanzee swelling cycle 100 % max 0 swelling 0 5 10 15 20 25 Ovulation (average) 30 35 day 40 Menstruation Graham (1970) Sexual swellings in primates • signal proceptive and receptive behavior • in many OWM and ape species highly exaggerated in size e.g., substantial increase in FF body weight (14% – 25%) • costly • evolved at least three times independently •adaptation? ANT 154B Lecture #9 course notes page 5 of 7 Boyko & Marshall page 8
value of the infant to the male, Valj, by multiplying pj by the probability the infant is not killed, which is the joint probability that no male kills it and it does not die from extrinisic mortality, !. This yields the following equation, given the termsVdefined in value of the infant to the male, alj,...
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- Winter '10
- Reproduction, Infanticide