Braendle, C. and Geissmann, T. (1997). Behavioural development of a pileated gibbon. International Zoo News 44: 4-16.

Behavioural development of a pileated gibbon

C. Braendle and T. Geissmann
Anthropological Institute, University Zürich-Irchel, Switzerland

Abstract: Only a few studies have been published on the behavioural development of gibbon infants, and most data refer to only two species of gibbons (Hylobates lar and H. syndactylus). The pileated gibbon (H. pileatus) is a little-known species of the lar group of gibbons. An infant pileated gibbon reared in its family group at the Zürich Zoo was observed for a total of 156 hours during its first year of life. The results show that: (1) The infant's behavioural development was largely comparable to that reported for other gibbon species of the lar group, except for the absence of "grooming" and low levels of "being groomed". (2) A reassessment of the developmental data available to date fails to provide reliable support for the hypothesis that siamangs have a longer maturation period than gibbons of the lar group.