Diet and Daily Feeding Amount of Hoolock Gibbon (Hoolock hoolock) at Nankang, Mt. Gaoligong

Through confirming the feeding characteristics and daily feeding amount of Hoolock gibbon (Hoolock hoolock), we discussed whether daily feeding amounts are different among individuals and seasons. Factors impacting daily feeding amount and characteristics were analyzed. According to results stated above, a base will be established for studying daily energy requirements and nutritional carrying capacity of Hoolock gibbon. The gibbons were observed and data were recorded by focal animal sampling method at Nankang of Mt. Gaoligong in spring and autumn from 2007 to 2008. The results showed that gibbons ate 40 parts from 36 botanic species. The feeding characteristics about food unit, feeding speed and weight of one food unit were different between fruits and young leaves. In spring and autumn, the percentage of fruits in daily feeding amount was the highest, the percentage of leaves was second, and the percentage of stems and flowers was the lowest. The daily feeding amount of the female in the family group was more than that of the male in spring and autumn. The daily feeding amount of the female solitary gibbon in spring was slightly more than that of the female in the family group. In spring, a feeding bout for feeding fruits by the solitary gibbon was twice longer than that of the family group, and the time for feeding young leaves was almost equal between the solitary gibbon and the family group. The daily feeding amount of the same individual in autumn was more than in spring, and the percentage of different parts of plants in daily feeding amount was also different between in spring and in autumn. The results showed that diet and amount of daily feeding part reflected the basic strategy for food selection. The size of individual between male and female, energy costs, food characteristics and requirements of physiology were factors impacting the daily feeding amount of Hoolock gibbon. The feeding bout of the gibbon was interrelated with amount of food resource in feeding tree.