Sex Differences, Seasonality, and Macronutrient Balancing in the Diet of Chimpanzees Inhabiting a Forest-Agricultural Mosaic

Many primates face spatial and temporal fluctuations in food availability, which can significantly affect their ability to meet nutritional requirements. Anthropogenic disturbances and influences, such as agriculture, human presence and infrastructures, can further impact seasonal food availability, dietary composition and nutrition. Primates residing in anthropogenic landscapes often incorporate cultivars into their diets. However, the nutritional drivers behind cultivar consumption are poorly understood. We examined variations in chimpanzee (Pan troglodytes verus) macronutrient intake from wild and cultivated foods between sexes and seasons over a 1year period in Bossou, Guinea. We used the geometric framework of nutrition to examine proportional contributions of macronutrients to the diet and nutrient balancing. We conducted

continuous focal observations of adult individuals ( n = 10) to record all feeding bouts and conducted nutritional analyses of plant foods (25 wild species; 11 cultivated species). We found no sex differences in chimpanzees for wild or cultivated food or macronutrient intakes; however, females showed higher intakes of total food (i.e. wild and cultivated combined), digestible fibre (NDF), and protein when controlling for metabolic body mass. There were no differences in wild or cultivated food intake between seasons; however, lipid and protein intake from cultivars were higher when wild fruit availability was low. Chimpanzees maintained a constant proportional intake of protein while allowing carbohydrates and lipid intakes to vary. Furthermore, they were

able to maintain a consistent balance of protein to non-protein (carbohydrates, lipids, and NDF) energy across the year. Our results suggest that Bossou chimpanzees suffered little seasonal constraints in food quality or availability since they were able to combine their consumption of available wild and cultivated foods to achieve a balanced diet. These findings contribute significantly to our understanding of primate nutritional requirements and their ability to meet these in disturbed environments.