Eastern Hoolock Gibbon

• Common Name: Eastern Hoolock Gibbon
• Taxonomy Classification Year: 1967
• Monkey Size: 60 to 90 cm (23.6 to 35.4 in)
• Skin Color(s): Black or gray-brown
• Habitat: Rainforest
• Diet: Omnivorous
• Native Countries: China

The eastern hoolock gibbon^[1] is a primate of the Hylobatidae family. Eastern hoolock gibbons don’t have a tail like all other monkeys but have a patch of hair in the anogenital region.

• They have long arms and relatively long legs with elongated hooked hands and opposable thumbs not used for tree swinging.
• The sexes are around the same size but differ significantly in coloration: males are black or blackish, with a white stripe across the eyes.
• Females are lighter in color, ranging from pale and tawny to grey-brown, darker on the neck and chest.
• Both sport black faces. White rings encircling the eyes and mouth of females give their face a mask-like appearance.

• Like all gibbons, eastern hoolocks have a ball joint that forms the wrist, connecting the hand to the forearm, and an adaptation that makes branchiation (swinging from one branch to another with their arms) much easier.
• Hollocks are the second largest gibbons after siamangs. They reach a height of 60-90 centimeters and weigh 6-9 kilograms.
• They are usually densely clustered in trees, concentrating on the tallest trees in the canopy and tending to choose hilltop or sloping sites.
• The species are more active in summer, waking up earlier than in winter, socializing more if they awake 8 to 10 hours daily, and sleeping just before nightfall.
• This species’ main threat is habitat loss and destruction due to human activities such as mining, logging, agriculture, and construction.