Primate Watching

Primatology

Taxonomy

Occurrence

The northern yellow-cheeked gibbon N. annamensis is a new species to the genus. It was
described in 2010 following years of discussion and research about the taxonomic uncertainty of
the gibbons distributed between the currently understood species boundaries for N. gabriellae
and N. siki. N. annamensis is distinguished from these latter two species based upon differences in
calls and genetic analysis. Morphologically it appears to be indistinguishable from N. gabriellae. Its
range is understood to extend from the Thach Han River in Quang Tri Province to the Ba River in
Phu Yen Province. This species is distributed through much of southern Laos east of the Mekong
and north-east Cambodia. About 200 groups have been recorded throughout its range in
Vietnam and there may be more in unsurveyed areas. The contiguous protected area of Dak Rong
and Phong Dien Nature Reserves appears to hold the largest population with over 80 groups, but
at much lower than natural densities as a result of previous hunting pressures. Song Thanh Nature
Reserve and contiguous forests and the forests in and around Kon Ka Kinh National Park and Kon
Cha Rang Nature Reserve may also have significant populations.

There are large populations reported from north-east Cambodia and likely in southern Laos, where the status is less well known. Globally, this species has not yet been evaluated on the IUCN Red List.