Seasonal Effects on the Nutrition and Energetic Condition of Female White-Faced Capuchin Monkeys
Date
2015-05-05
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Abstract
Seasonal variation in food availability can ultimately affect female reproductive success. I investigated the effect of seasonality on the behavior, nutritional intake and physical condition of female white-faced capuchins in Sector Santa Rosa, Costa Rica. Capuchins are omnivorous neotropical primates that focus foraging effort on fruit and invertebrate resources. My project objectives were to 1) document the dietary profile of females; 2) measure the extent of seasonal variation in diet; 3) determine if seasonal variation in fruit abundance affects the physical condition of females; and 4) identify which ecological and social variables most strongly predict variation in energy balance. I collected 12 months of behavioral observations on 25 adult females living in three habituated groups between September 2009 and April 2011. I conducted phenological surveys and nutritional analyses of foods to document energy availability and nutritional intake. I measured the creatinine concentration and specific gravity of urine samples to estimate the relative muscle mass of females, and I ran radioimmunoassays to quantify urinary C-peptide, a biomarker for energy balance. Females exhibited seasonal changes in foraging behavior, diet and physical condition. During low fruit abundance months, invertebrates comprised a larger proportion of total energy and protein intake than did fruit. Lepidopteran larvae (i.e., caterpillars) were a particularly important invertebrate resource and comprised a large proportion of energy and protein intake during the early rainy season (May – August). Despite seasonal dietary shifts, females did not meet estimated energy requirements in some months. The relative muscle mass of females was higher during months with high versus low fruit abundance, and varied by group according to the energy available from ripe fruit. In addition, females produced urinary ketones during months with low fruit and energy intake. C-peptide analysis accurately reflected energy balance and indicated that females experienced low energy balance during low fruit months. Ripe fruit energy density (kJ/ha) was the single most important predictor of female energy balance. This extensive examination of dietary flexibility and the physiological costs associated with living in a seasonal habitat will help us to elucidate the relationship among environmental conditions, behavior and reproductive success in female primates.
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Anthropology
Citation
Bergstrom, M. L. (2015). Seasonal Effects on the Nutrition and Energetic Condition of Female White-Faced Capuchin Monkeys (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/27720