Geissmann, T. (1995). The yellow-cheeked gibbon (Hylobates gabriellae) in Nam Bai Cat Tien (southern Vietnam) revisited. Primates 36: 447-455.

The yellow-cheeked gibbon (Hylobates gabriellae) in Nam Bai Cat Tien (southern Vietnam) revisited

T. Geissmann
Anthropological Institute, University Zürich-Irchel, Switzerland

Key words: Gibbons; yellow-cheeked gibbon; Hylobates gabriellae; Vietnam; song; Hylobates concolor group.

Abstract: Data concerning the status, habitat and vocalizations of yellow-cheeked crested gibbons (Hylobates gabriellae) were collected during a short field trip to the Nam Bai Cat Tien National Park (southern Vietnam). Nam Bai Cat Tien may be the southernmost locality where crested gibbons (i.e. the Hylobates concolor group) still survive. Fewer songs were heard at Nam Bai Cat Tien National Park than at other crested gibbon sites visited by the author. At least two gibbon groups appear to have been greatly reduced in number since previous surveys in the park. There is some evidence that both the gibbon population and the gibbon habitat in Nam Bai Cat Tien are disturbed. The first case of a great call solo song in wild gibbons of the concolor group is reported. Great calls of H. gabriellae are described and documented with sonagrams for the first time. They differ from those previously described for H. leucogenys.