Geissmann, T. 1984: Pair-bonding function of siamang (Hylobates syndactylus) duet song. International Journal of Primatology 5: 341 (Abstract only).

Pair-bonding function of siamang (Hylobates syndactylus) duet song

T. Geissmann

Anthropological Institute, University Zürich-Irchel

Siamang gibbons produce long and complex duet songs. Although hypothetical mechanisms have been set forth to explain the evolutionary constraints for the development of duetting, only one of them could reasonably account for the tremendous complexity of the siamang duet song. The hypothesis that duetting might act as a reinforcement of the pair bond has repeatedly been suggested for several duetting bird and primate species. Until now, investigations which actually could demonstrate the premises underlying the pair-bonding hypothesis were lacking. Two newly formed pairs of captive siamangs have been observed. Qualitative and quantitative investigations of duet songs have been carried out in different temporal stages of pair formation. The results proffer concrete data, that a pair-bonding effect has actually to be assigned to the siamang duet song.