Abstract
Human female reproductive function is highly sensitive to current energetic condition, indicating adaptation to modulate reproductive effort in accordance with changing ecological conditions that might favor or disfavor the production of offspring. Here, we test the hypothesis that reproductive capacity in female chimpanzees is likewise limited by current energetic condition. We used 12 years of data on wild chimpanzees (Pan troglodytes schweinfurthii) in the Kanyawara community of Kibale National Park, Uganda, to examine the relationship of dietary quality, as assessed by fruit components of the diet, to the occurrence of sexually receptive females, concentrations of ovarian steroid hormones, and timing of conception. We found that the frequency of females having sexual swellings was positively related to the consumption of drupe fruits. Estrogen levels of both cycling and noncycling females increased during seasonal peaks in the consumption of drupe fruits. When average fruit consumption remained high across months, females conceived more quickly. These results support the hypothesis that cycling and conception in chimpanzees are contingent upon high energy balance, and they indicate that the availability of fruit is a key variable limiting reproductive performance in chimpanzees. Chimpanzees appear to share with humans a reproductive system that is primed to respond to proximate levels of energy acquisition.
Highlights
Human female reproductive function is highly sensitive to current energetic condition, indicating adaptation to modulate reproductive effort in accordance with changing ecological conditions that might favor or disfavor the production of offspring
Conception data from Hanuman langurs (Presbytis entellus: Koenig et al, 1997), long-tailed macaques (Macaca fascicularis: van Noordwijk and van Schaik, 1999), and orangutans (Pongo pygmaeus: Knott, 1999) indicate a similar sensitivity to seasonal changes in food abundance. These findings suggest that females might become more likely to conceive as a result of a seasonal increase in food availability. Such a pattern would conform to the reproductive system of humans, in which the probability of conception is controlled by varying ovarian hormone production in relation to energetic condition (Ellison, 1990, 2003; Ellison et al, 1993)
We investigated the relationship of diet to four reproductive events: occurrence of sexual swelling, timing of conception, timing of birth, and waiting time to conception
Summary
Human female reproductive function is highly sensitive to current energetic condition, indicating adaptation to modulate reproductive effort in accordance with changing ecological conditions that might favor or disfavor the production of offspring. Conception data from Hanuman langurs (Presbytis entellus: Koenig et al, 1997), long-tailed macaques (Macaca fascicularis: van Noordwijk and van Schaik, 1999), and orangutans (Pongo pygmaeus: Knott, 1999) indicate a similar sensitivity to seasonal changes in food abundance These findings suggest that females might become more likely to conceive as a result of a seasonal increase in food availability. Such a pattern would conform to the reproductive system of humans, in which the probability of conception is controlled by varying ovarian hormone production in relation to energetic condition (Ellison, 1990, 2003; Ellison et al, 1993). We do so by examining dietary composition in relation to
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
