White-cheeked Gibbon Scientific Name: Hylobates leucogenys Range: Laos, Vietnam, and Southern China Habitat: Tropical rainforests and monsoon forests Natural Diet: Ripe fruit, leaves, and a small amount of invertebrates Zoo Diet: Fruit, vegetables, and commercial primate biscuit Physical  Characteristics: White-cheeked gibbons are 18-25 inches tall and weigh 15-20 pounds. All infants are a beige color.  By 1 ½ years old, their fur changes to black with white cheek patches.  At about 5-7 years, males remain black and females become a beige color again. Behavior: Gibbons are arboreal (live in the trees) and spend most of their time in the canopy of the forest.  They almost never come to the ground. They live in small, monogamous (having only one mate) families consisting of a mated pair and their offspring.  At about eight years old, the young leave the family group.  Gibbons are one of the few apes where the adult female is the dominant animal in the group. Reproduction: A single infant is born after a gestation period of 7-8 months.  The infant is dependent on its mother for 18 months. Notes:   Grooming (removing dirt and parasites from the fur) is an important social activity between gibbons within a family group.  Gibbons are known for their loud calls.  The male and female both “warm up,” then they take turns making loud calls.  The song will end with a male call.  During the calling, the gibbons are often doing acrobatics in the trees.