Abstract # 939 Event # 100:

Scheduled for Friday, August 19, 2005 10:15 AM-10:30 AM: Session 7 (Parliament Room) Oral Presentation

Annual Variation in the Diet of Phayre's Leaf Monkeys (Trachypithecus phayrei) in Phu Khieo Wildlife Sanctuary, Thailand

S. A. Suarez
Stony Brook University, Anthropology Department, 5th Floor SBS Building, Stony Brook, NY 11794-4364, USA
     Asian leaf monkeys show morphological adaptations for consuming a large amount of leaves, yet most show a diversity of diet choice. Annual variation in leaf and fruit consumption influences activity budget, daily path length, home range size, energy intake and within and between group competition. We investigated annual variation in Phayre’s leaf monkey diet as part of a long-term study of their behavioral ecology and sociobiology. Five 20-minute focal samples were conducted each month for all adult monkeys in three social groups (N = 23), with instantaneous sampling of behavior (including feeding behavior) at one-minute intervals. Feeding time is calculated as a percentage of the total instantaneous samples for each category. The results for twelve months indicate that leaves were the most important food item, representing about half of the diet, with foraging effort divided evenly between mature and young leaves. Fruit represented about 40% of the diet, with monkeys consuming primarily the seeds and pulp from immature fruits. Bamboo shoots, insects, and flowers represented most of the remaining 10% of the diet, with foraging efforts on each concentrated in only one or two months. Diets varied across groups and months, reflecting differences in both habitat quality and availability of preferred food items. This project was funded by the National Science Foundation (BSC-0215542).