Western Hoolock Gibbon

• Common Name: Western Hoolock Gibbon
• Taxonomy Classification Year: 1834
• Monkey Size: 60 to 90 cm (23.62 to 35.43 in)
• Skin Color(s): Black or dark brown
• Habitat: Forest, rainforest, scrub forest
• Diet: Omnivorous
• Native Countries: Bangladesh, India, Myanmar, China

The Western Hoolock gibbons^[1] are three species of primates in the Hoolock genus of the gibbon family, Hylobatidae, endemic to Myanmar, eastern Bangladesh, northeastern India, and southwestern China.

• Hoolock gibbons are the second largest gibbon after the siamangs. They weigh between 6 and 8 kg.
• Hoolock gibbons are characterized by longer hair, curved white eyebrow bands, and a slightly triangular head.
• This species is bicolor: adult males are entirely black, while adult females are dark brown with black on the neck, chest, and face. In some subpopulations, males have more pronounced eyebrows than in others.
• Males may also have a white foreskin tuft and may show white on the chin and cheeks. Some females have lighter fur on their hands and feet.
• Hoolock gibbon is unique among gibbon species in having only 38 chromosomes compared to 44 for other members of its subgenus.

• Like other gibbons, Western Hoolock gibbons are diurnal and arboreal, gliding through trees with their long arms.
• The pair, with its offspring (usually one or two), inhabit a stable and heavily defended territory.
• Sometimes solitary adults, usually subadults recently expelled from their family group, establish solitary territories.
• Their calls are used to locate family members and keep other gibbons out of their territory.
• Unlike other gibbon species, male and female hoolock gibbon vocalizations are the same and relatively simple.