FEMALE RANK AND FEEDING STRATEGIES IN A FREE-RANGING PROVISIONED TROOP OF JAPANESE MACAQUES

The pattern of feeding in a free-ranging troop of Japanese macaques reflected female rank. High-ranking females (HRF) obtained about 3/4 of their daily digested energy from artificial foods and 1/4 from natural sources, whereas low-ranking females (LRF) received roughly equal proportions of their daily digested energy from the two sources. LRF adjusted their feeding strategies in relation to seasonal variation of food supply. In winter, when food was scarce, dietary composition was dissimilar for HRF and LRF. The LRF strategy consisted of (1) finding new food resources and increasing the number of food items by 50%, (2) extending feeding time by 15%, while (3) reducing by 10% the time allocated to rest and social activities compared to HRF. In summer, when many fruits and seeds were available, dietary composition was similar, and the LRF strategy consisted of points 2 and 3 mentioned above. They also minimized agonistic interactions with HRF by reduing artificial food intake by 7% and compensating with natural food.