The transition from the female-like great calls to male calls during ontogeny in southern yellow-cheeked gibbon males (Nomascus gabriellae).

It is well known that gibbons emit a pattern of vocalizations, which is specific for species and sex. A previous study showed, however, that immature southern yellow-cheeked gibbon (Nomascus gabriellae) males produce only female-like great calls from 2.3 to 5.

A first report of separation calls in southern yellow-cheeked gibbons (Nomascus gabriellae) in captivity.

The effects of social separation, including vocalization, have been studied for a very long time in non-human primates under laboratory conditions. As part of the long-term research on the vocal behaviour of Nomascus gibbons in zoos, this study provides the first record of calls of the southern yellow-cheeked gibbon (Nomascus gabriellae) in response to involuntary separation. Our study revealed that calls were also emitted by an infant (aged 1 year 8 months), and that the acoustic structure of the infant's calls was similar to that of older individuals' calls.

Fur color change and hormonal development in captive females of northern white-cheeked (Nomascus leucogenys) and buff-cheeked (Nomascus gabriellae) gibbons.

Gibbons of the genus Nomascus exhibit strong sexual dichromatism in fur color. Change of fur color in sub-adult wild Nomascus females is associated with the onset of puberty and the time of their dispersal. The variability in fur change may be influenced by social factors.

The traits of the great calls in the juvenile and adolescent gibbon males Nomascus gabriellae.

Knowledge about vocal ontogeny and vocal plasticity during ontogeny in primate species is central to understanding the evolution of human speech. Vocalizations in gibbons (Hominoidea) are very interesting and contain complex species- and sex-specific patterns. However, ontogeny of gibbon songs is little studied.

Production of a female-specific great call in an immature male gibbon, the Nomascus genus.

Production of species- and sex-specific vocalisation is a trait characteristic of all gibbons. However, the mechanisms of gibbon vocalisation ontogeny and the manner of developing sex-specific vocal patterns are not yet known. We recorded vocal behaviour of a juvenile male northern white-cheeked gibbon (Nomascus leucogenys).