Sumatran orangutan

Pongo abelii

Orangutans live in lowland or hilly tropical rainforests of the island of Sumatra in Indonesia. "Orangutan" comes from the Malay orang meaning man, and hutan meaning wilderness or jungle.

Orangutan behavior and facts

  • Orangutans eat eggs, fruit, insects, leaves, small invertebrates and young shoots.
  • They are diurnal (active during the day), solitary, and arboreal, almost exclusively living in the trees. They build nests in trees for sleeping.
  • An orangutan's hair is shaggy and red; feet and hands are similar and used for grasping; long arms are adapted to brachiation (swinging from limb to limb).
  • Males have dark face flanges or pads (also called flaps) used in dominance displays.
  • Orangutans are highly intelligent, with large brains.
  • Males have pendulous (hanging) laryngeal sacs that create resonating chambers for loud calls that can be heard up to a mile away. The calls may repel male rivals and advertise a male's availability for mating.

From birth to death

  • Birth interval: 7 to 8 years
  • Gestation: 232 to 265 days (7.75 to 8.8 months)
  • Birthing twins is rare; babies nurse up to three years
  • Sexual maturity is reached at 15 years of age for females
  • Lifespan: 53 to 58 years; 50 years in captivity

Vital statistics

  • Weight: males 130 to 200 pounds; females 90 to 120 pounds
  • Height: males 4.5 to 5 feet; females 4.5 feet


Endangered due to habitat destruction

Orangutans, the Oregon Zoo and you

The two species of orangutan are Bornean and Sumatran. They have been isolated from each other for more than one million years. The zoo is home to Sumatran orangutans. Inji was born in the wild and arrived at the zoo in 1961 with her mate Harry. Together they had seven offspring before Harry died in 1994.

Kutai was a male orangutan born at a Kansas zoo but was the grandson of Inji and came to the Oregon Zoo in 2001. As Kutai aged, he became more dominant than Inji, often demanding the enrichment and food for himself. Occasionally, Inji stood up to him, despite being twice her size. But they maintained a close relationship. During Inji's gallbladder surgery, Kutai checked on her every time he could.

On Jan. 4, 2013, Kutai died following a monthlong illness. He was much loved by visitors and those who cared for him, and will be remembered for his mischevious, sweet nature. He touched many hearts and helped raise awareness about the threats facing orangutans in their native Indonesia.

Inji lives in the Red Ape Reserve exhibit. Her diet consists of monkey chow, fruits and vegetables.

Orangutans are critically endangered by loss of habitat from logging, conversion of forest into palm oil plantations and farms, and fragmentation by roads.