Activity budget, travel distance, sleeping time, height of activity and travel order of wild East Bornean Grey gibbons (Hylobates funereus) in Danum Valley Conservation Area

作者：Inoue Yoichi^*; Sinun Waidi; Okanoya Kazuo

来源：Raffles Bulletin of Zoology, 2016, 64: 127-138.

• gibbon behavior
• activity pattern
• seasonal change
• infant carrying by male

Activity budget, travel distance, sleeping time and height of activity of two wild East Bornean grey gibbon (Hylobates funereus) groups and travel order of one group were investigated during the dry and wet season at the Danum Valley Conservation Area, Sabah, Malaysia. One male showed seasonal change in his behaviors between the dry season (August) and wet season (December). He spent more time engaged in moving, playing and grooming, traveled longer and entered the sleeping tree later in the dry season when fruit was abundant but did the opposite in wet season. On the other hand, another male gibbon whose family had a new-born baby did not show a similar seasonal behavioural change between the dry season (May-June) and wet season (December). Fruit availability and gibbon family composition, especially whether the family had a new-born baby, may have an influence on the activity budget, movement and sleeping time of East Bornean grey gibbons. Early night-tree entry may be influenced by combined factors such as fruit availability, predator avoidance and fruit competition with other animals. The female gibbon's activities occurred at greater height above the ground compared to that of males in the early morning and the late afternoon. Similar to other gibbons, the female East Bornean grey gibbon led the group more often than the male. In addition, a rare observation was made of infant carrying by the adult male when the infant was 29 months old.

• 出版日期2016