Geissmann, T., 1990: Songs of different types of hybrid gibbons follow a common principle. 13th Congress of IPS Abstracts, p. 186. Nagoya.

Songs of different types of hybrid gibbons follow a common principle

T. Geissmann

Anthropological Institute, University Zürich-Irchel

Gibbon songs contain species specific characteristics. Previous studies have indicated that these characteristics are largely genetically determined. Hybrids between several species of gibbons have repeatedly been bred in captivity. For this report, female great calls of different types of hybrid gibbons have been compared. The parental species of these hybrids include all species of the lar group gibbons: Hylobates agilis, H. lar, H. moloch, H. muelleri, and H. pileatus. The results of this study are the following:

1. Great calls of hybrid gibbons differ from great calls of parental species.
2. These differences follow a common principle.
3. The hypothetical great call structure can be predicted for hybrid combinations and generations which have not been bred or studied yet.
4. The common principle underlying the great call structure of the various hybrids permits to test whether or not similarities between great calls of some species of the lar group are based on homology or on convergent evolution.