Abstract # 117:

Scheduled for Sunday, September 18, 2011 10:30 AM-10:45 AM: Session 16 (Salon F (Sixth Floor)) Oral Presentation


JAVAN GIBBON (HYLOBATES MOLOCH) DIETS AND FOOD PREFERENCES IN SUBMONTANE FOREST IN THE GUNUNG HALIMUN-SALAK NATIONAL PARK, INDONESIA

S. Kim1,2, S. Lappan2,3 and J. C. Choe2
1Seoul National University, Department of Biological Sciences, Seoul 151-742, USA, 2Ewha Woman's University, 3Appalachian State University
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In Southeast Asian forests with pronounced temporal variation in fruit availability, many frugivorous primates switch from preferred fruits to lower-quality foods when fruit is scarce. However, gibbons are reported to rely heavily on ripe fruit throughout the year. We collected feeding data using focal sampling from adults in three Javan gibbon groups in the Gunung Halimun-Salak National Park during all-day follows from April 2008-March 2009 (N=173 days) and collected phenological data monthly from 25 10x50 m plots to determine gibbon food preferences and responses to variation in food availability. Fruit comprised >60% of annual diet and >=40% of the diet in every month for each group. Gibbons ate parts of >53 plant species. Seventeen of 48 fruit species and 7 of 17 flower species eaten were preferred (oversampled relative to abundance; Si >=1.5). Most species were eaten in low quantities. Only six species, all preferred, comprised >=5% of annual diets. These six species together comprised 41-45% of annual diets. Fruit consumption peaked in different seasons for different groups. Multiple regression analysis of the effects of plant part availability on diets identified fruit availability as a significant predictor (p<0.05) of the percentage of fruit-feeding time in only one group. Our results suggest that the availability of specific preferred species may be a more important determinant of gibbon diets than overall fruit availability.