1Anthropology, University of Calgary, 2Interdepartmental Doctoral Program in Anthropological Sciences, Stony Brook University
Saturday All day, Park Concourse
Physical condition has a direct impact on female reproductive function as an increase in energy balance during the preconceptive period can influence the production of reproductive hormones. If a female cannot maintain a sufficient energy balance when cycling, she may be unable to produce the required hormone levels and consequently, may be unable to conceive. Here, we investigate the relationship between energy balance and ovarian hormone production, and the dietary strategies used to maintain adequate energy balance to ensure conception. To do so, we observed eight wild adult female Sanje mangabeys during 16 weeks prior to conception and collected data on urinary C-peptide (UCP, an indicator of energy balance), fecal estradiol (fE2), nutritional and feeding behavior, and phenology to control for food availability. Mean UCP (r = 0.480, p=0.019) and number of cycles before conception (r = - 0.591, p=0.004) were significantly correlated with mean fE2 level, explaining 36.6% of the variance in fE2 during preconception (F = 4.619, p=0.026). With each successive cycle both mean UCP and fE2 increased with the highest levels observed during the conceptive cycle. Females conceiving during the high food period improved dietary quality by consuming a greater proportion of fat and protein compared to females conceiving in the low food period. In contrast, the latter females tended to spend more time feeding and had a faster food intake rate (g/h), consuming more food overall. Thus, female mangabeys responded to variation in food availability by utilizing divergent strategies in order to increase their energy balance.
Funding for this project was provided by the National Science Foundation DDIG (BCS-0925901, GM; BCS-0925690, DF), the Leakey Foundation (GM, DF), Primate Conservation, Inc. (GM, DF), Conservation International Primate Action Fund (GM), Margot Marsh Biodiversity Fund (DF), Sigma Xi (DF), UTSA International Education Fund (GM) and Idea Wild (GM, DF).