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Diurnal variation in nutrients and chimpanzee foraging behavior
Bryce A Carlson1, Jessica M Rothman, John C Mitani
1Department of Anthropology, Purdue University, 700 W. State St., West Lafayette, IN 47907, USA. bryce@purdue.edu
American Journal of Primatology
|January 10, 2013
Summary
Chimpanzees adjust their leaf-feeding behavior throughout the day, consuming more nutrient-rich leaves in the evening. This diurnal feeding pattern suggests primates track food quality over short time scales.
Area of Science:
- Primate Ecology
- Nutritional Ecology
- Behavioral Ecology
Background:
- Primate feeding behavior exhibits variability across multiple timescales.
- Understanding daily fluctuations in feeding behavior is crucial but understudied.
- Resource availability and food nutritional content influence feeding patterns.
Purpose of the Study:
- To investigate diurnal variation in chimpanzee feeding behavior.
- To examine the relationship between chimpanzee feeding and leaf nutritional composition over a single day.
- To identify factors driving short-term changes in primate foraging.
Main Methods:
- Observing chimpanzee feeding on two sapling species (Pterygota mildbraedii, Celtis africana) at Ngogo, Kibale National Park, Uganda.
- Analyzing the diurnal variation in the nutritional composition of these leaves.
- Correlating feeding patterns with changes in nutrient content throughout the day.
Main Results:
- Chimpanzees consumed more leaves in the evening compared to the morning.
- Leaf nutritional quality improved diurnally, with lower cellulose/lignin and higher carbohydrates in the evening.
- Specific nutrient increases (sugars, starch) were observed in P. mildbraedii and C. africana leaves by evening.
Conclusions:
- Chimpanzees actively select food resources based on their peak nutritional quality within a day.
- Primate foraging behavior demonstrates tracking of short-term (hourly) nutrient composition changes.
- Future nutritional analyses of food sources must account for diurnal sampling time for accuracy.
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