Multi-female group in the southernmost species of Nomascus. Field observations in Eastern Cambodia reveal multiple breeding females in a single group of Southern yellow-cheeked crested gibbon Nomascus gabriellae

Previous field studies of gibbon groups of the genus Nomascus have shown that multi-female polygynous groups are present and quite common in the northernmost species. Our research shows that multi-female groups are also present in the southernmost species, the Southern Yellow-cheeked Crested Gibbon Nomascus gabriellae (Thomas). Various gibbon groups are being followed and habituated in Seima Protection Forest by local and international researchers. Data collected during the first nine months of observations shows the presence of a stable multi-female family group in the study area, with two breeding females with infants. This is the first time this has been reported and confirmed for this particular species of Nomascus.