Scientific Name: Nomascus gabriellae
Eating mostly fruit, gibbons aid in seed dispersal throughout the forests in which they live, promoting plant growth.
Mainly arboreal, this primate’s family name, Hylobatidae, appropriately stems from the Latin hylobates which means “dweller in the trees.” Gibbons are considered the most successful apes (although smaller than great apes) in terms of their diversity and abundance. The buff-cheeked gibbon is the second-most prevalent crested gibbon seen in zoos.
STATUS: Buff-cheeked gibbons are listed as Endangered by the International Union for Conservation of Nature (IUCN). Their numbers have decreased by more than about 50% over the past 45 years mainly due to habitat loss and hunting. Natural predators include raptors and pythons. The L.A. Zoo’s buff-cheeked gibbons are part of a Species Survival Plan breeding program.
HABITAT: Living in Southeast Asia (Cambodia, Vietnam, and Laos), buff-cheeked gibbons prefer tall evergreen and semi-evergreen tropical forests, however they may also inhabit nearby mixed bamboo, riverine, woodland, and gallery forests. They usually live at altitudes of about 1,300-5,000 ft.
DIET: Buff-cheeked gibbons are omnivorous. They prefer to eat sweet fruits, but they also feed on leaves, insects, and bird eggs.
PHYSICAL CHARACTERISTICS: Adult males are all black with buff cheeks, and weigh up to 18 pounds. Adult females are cream or buff-colored, their heads are topped with black and they are slightly heavier but smaller than males. Like other apes, gibbons lack tails. Hairless, calloused pads of skin on their rears allow them to sit for long periods without losing circulation to their legs. Their long arms (approximately 40% longer than their legs) and elongated hook-like fingers are quite useful when swinging through the trees, their main form of locomotion. In fact, these acrobatic apes can swing faster than a human can run! Good binocular vision helps them judge distances while swinging from one tree to the next. Gibbons have fully opposable thumbs for manipulating objects, grasping branches and picking fruits with precision. An inflatable throat sac amplifies buff-cheeked gibbon vocalizations.
Gibbon Glee Club
Gibbons use their loud voices to defend their territories, and singing is essential in forming and maintaining pair-bonds. Younger, lone males sing to find mates. Monogamously paired males and females sing duets early in the morning to assert their territory and reaffirm their relationship. Gibbon calls are species-specific; however, females generally make ascending calls while males use territorial barks and hoots.
Gibbons usually forage throughout the day, but feed mostly in the morning. They live in families averaging three to six members. Gibbons become sexually mature at seven to nine years old. Females are pregnant for seven months, and typically give birth to one infant born with buff fur like its mother. The infant’s color changes to black at about six months. Then, males stay black and females change back to buff. When conflict between maturing offspring and their parents intensifies, the sub-adults are driven out of the group. This prevents in-breeding. In the wild, gibbons live 25-30 years on average.