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Red-cheeked Gibbon (Nomascus gabriellae) Fact Sheet: Summary

Red-cheeked Gibbon (Nomascus gabriellae) Fact Sheet

Female red-cheeked gibbon holding leaves

Adult female red-cheeked gibbon, Nomascus gabriellae

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.


Taxonomy Physical Characteristics

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Primates

Family: Hylobatidae — gibbons

Genus: Nomascus

Species: Nomascus gabriellae — red-cheeked gibbon; see synonyms, below

Source: ITIS (2018)



  • Hylobates gabriellae (Geissmann 2008)
  • Southern yellow-cheeked (crested) gibbon (ITIS 2018)
  • Yellow-cheeked crested gibbon (Traeholt et al. 2005)
  • Buff-cheeked gibbon (ITIS 2018)
  • Golden-cheeked gibbon (Varsik and Santa Barbara Zoological Gardens 2001)


Body Weight

  • Adult: 5-12 kg (11-26 lb) (Sheeran and Mootnick 1998; Bartlett 2011; Bạch Thanh Hải, personal communication, 2018)
  • Infant: 0.5-1 kg (1-2 lb) (Bạch Thanh Hải, personal communication, 2018)

Head-body Length

  • Male: 45.5-49.6 cm (17.9-19.5 in) (Chivers et al. 2013)
  • Female: 46-47.5 cm (18-18.7 in) (Chivers et al. 2013)

Pelage (Traeholt et al. 2005; Chivers et al. 2013; also see Mootnick and Fan 2011)

  • Males and females have different color hair, like other Nomascus species.
  • Adult male black, except for yellow/orange cheeks and slightly rusty-colored chest. Adult female pale yellow to orange-yellow. May have black crown. May have slightly darker chest.
  • Infants born buff-yellow. Begin to transition to black coloration (same as adult males) at about six months old. Retain this coloration as juveniles and subadults. As adults, males retain black coloration. Females transition back to yellow upon reaching maturity.
Distribution & Status Behavior & Ecology

Southern Vietnam and eastern Cambodia. After taxonomic split with N. annamensis, no longer thought to inhabit Laos (Rawson et al. 2011; Thien et al. 2017).

Wet evergreen and semi-evergreen forests. Mixed deciduous forest (especially where mixed with patches of evergreen forest), bamboo forests, and rattan (Old World palms) (Traeholt et al. 2005; Rawson et al. 2009; Chivers et al. 2013).

IUCN Status
Endangered (2015 assessment) (Rawson et al. 2020)

CITES Appendix
Appendix I (UNEP 2020)

Other Designations
Legally protected in Vietnam and Cambodia (Chivers et al. 2013).

Populations in the Wild
Population trend: decreasing (Geissmann et al. 2008; Rawson et al. 2011). Highest densities in undisturbed forests (Chivers et al. 2013; Vu et al. 2016).
Few robust population estimates:

  • Cambodia (estimates missing from some regions): 450-1,350 groups (Chivers et al. 2013).
  • Vietnam: Approximately 600 groups (see references in Bach et al. 2017), plus groups from non-surveyed areas; considered “common” (Traeholt et al. 2005). Cat Tien and Bu Gia Map National Parks support the largest N. gabriellae populations in Vietnam (Rawson et al. 2011).

Threats to Survival

  • Hunting for wildlife trade. Mothers shot and infants traded for pet trade (e.g., Rawson et al. 2011).
  • Also hunted for food (Geissmann et al. 2008; Rawson et al. 2011; Chivers et al. 2013) and traditional medicine (Rawson et al. 2009).
  • Habitat loss: infrastructure development, agriculture, illegal logging (Rawson et al. 2009)

Activity Cycle
Diurnal—active early morning until late afternoon (Chivers et al. 2013).

Movements (Kenyon et al. 2011; Chivers et al. 2013)
After reaching sexual maturity, females disperse from natal territories to nearby territories. Males may disperse farther, if no space available in nearby territories.

Social Behavior
Territorial (Rawson et al. 2011). Family unit comprised of adult pair and offspring. Usually 4-5 individuals (range: 3-6) in a group (Kenyon et al. 2011); however, larger multi-female groups have been observed (Barca et al. 2016).

Often loud calls around sunrise (Rawson 2004; Rawson et al. 2009). Adult male and female usually sing in duet (Geissmann 2002). Singing bouts about 12 minutes long (Rawson 2004). Immatures do not usually duet but occasionally call with group (Bartlett 2011).

Mainly figs and other fruits; flowers, leaves, and shoots (Chivers et al. 2013; Bach et al. 2017).
Also insects and bird eggs (Bach et al. 2017).

Not well known. Pythons, leopards, birds of prey (eagles), large macaques (Bạch Thanh Hải, personal communication, 2018).

Arboreal. Swing among tree branches from hand to hand (“brachiation”), climb, run on two feet, leap (Fleagle 1976).

Relationship with Humans
Shy around humans (Traeholt et al. 2005). Cryptic—difficult to observe in the wild (Barca et al. 2016). In southern Vietnam, held as pets in hotels and private zoos. Also hunted—see Threats to Survival (Rawson et al. 2011).

Reproduction & Development Species Highlights

Monogamous. Uncommonly, extrapair copulations (Kenyon et al. 2011) and multi-female groups (Barca et al. 2016).

Sexual Maturity
Not well known for Nomascus (Rawson et al. 2011).
Among gibbons, generally, mature as early as 5 years in managed care and likely at 7-8 years in the wild (Geissmann 1991).

Ovarian Cycle
About 21 days [data from 7 cycles of 2 females], similar to other gibbons (Geissmann and Anzenberger 2009).

Not known. Likely similar to N. leucogenys, 200-212 days (about 7 months) (Geissmann 1991).

Litter Size
One young (Rawson et al. 2011)

Interbirth Interval
One observation in N. gabriellae of 17-22 months (Chivers et al. 2013). Approximately 2-4 years in some other gibbons (Traeholt et al. 2005; see references in Bartlett 2011).

Age at Weaning
Generally, gibbons weaned during second year (Bartlett 2011).

Typical Life Expectancy
Wild populations: not known
Managed care: no AZA estimates

Feature Facts

  • Very long arms for swinging and climbing in trees (Cheyne 2011)
  • Stable pair bonds (Bartlett 2011)
  • Gibbon songs may strengthen bonds between mates and advertise territory holdings (Bartlett 2011)
  • Female and male sing different songs (Rawson 2004)
  • Compete with other animals (e.g., macaques, squirrels) for ripe fruits (Hai et al. 2018)
  • Important disperser of seeds for the tropical rainforest canopy tree, the Pacific walnut (Dracontomelon dao) (Hai et al. 2018)

About This Fact Sheet

For bibliography, click the tab at the top of this page.


© 2018-2020 San Diego Zoo Wildlife Alliance. IUCN Status updated Nov 2020.


How to cite: Red-cheeked Gibbon (Nomascus gabriellae) Fact Sheet. c2018-2020. San Diego (CA): San Diego Zoo Wildlife Alliance; [accessed YYYY Mmm dd].
(note: replace YYYY Mmm dd with date accessed, e.g., 2018 Dec 31)


Disclaimer: Although San Diego Zoo Wildlife Alliance makes every attempt to provide accurate information, some of the facts provided may become outdated or replaced by new research findings. Questions and comments may be addressed to

Gentlemen Prefer Blondes

Adult male red-cheeked gibbon, black hair

As adults, male and female gibbons have different colored hair. (Compare this photo of a male to the female shown, above.)

Both sexes begin life with buffy-yellow hair that changes to black as they become juveniles.

In adulthood, males retain their black coloration, while females once again "go blonde."

Image credit: © San Diego Zoo Wildlife Alliance. All rights reserved.

Red-cheeked Gibbon Distributon

Distr. map of Red-cheeked Gibbon, N. gabriellae

The red-cheeked (or southern yellow-cheeked crested) gibbon occurs in Cambodia and Vietnam.

Adapted from according to IUCN fact sheet. Click here or on map for detailed distribution (IUCN).

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