Speaker
Van Bang Tran
(Southern Institute of Ecology, Vietnam Academy of Science and Technology)
Description
Vocalization is an important characteristic of gibbons (family Hylobatidae) in Southeast Asia because it is used to determine and protect group territory and in social behaviour. Even though the important role of calling in gibbon life, understanding the calling behaviour of species often based on short time of study rather than in long-term study because of the limitation of presence surveyor in the field. The one-year data of acoustic that recording by the automatic acoustic recording (Wildlife Acoustic SM2) in the mixed-conifer and broadleaf of Bidoup – Nui Ba National Park was explored to understand the calling behaviour of southern yellow-cheeked gibbon (Nomascus gabriellae). For a year of monitoring, gibbon’s song, including solo and duet song, were recorded in 195 days with 264 times and the number days that detected call vary over the month with a maximum in October 2015 and minimum in May 2015. The earliest time of day the gibbon made a call was 5:30 and the last call of the day at 13:00. Regarding the number of groups made a call at the same time, about 18.94% of the total file obtained a call from two or three groups and most of them came from one group. Within the 5-minutes of recording, the gibbon produced average 7.98 calls (range from 1 to 17), of which 3.7 are duet calls (range from 1 to 8). In this study, the species produced more calls in the rainy season than in dry season.
Co-author
Dr
Yu-Huang Wang
(Indepent Scholar)
