Overview
The Sumatran orangutan (or Pongo abelii) is a great ape endemic to the Indonesian island of Sumatra. They inhabit tropical rainforests, including lowland swamp forests and mangroves. They have long orange hair, which is lighter and silkier than that of their Bornean relatives. Males, once sexually mature, develop large cheek pads (flanges) and a throat‑sac, and often grow beards and longer facial hair. Males are significantly larger than females, weighing 50kg to 90kg, and standing up to 1.8m tall. Adult females typically weigh about 30kg to 50kg and reach a height of around 1.3m when standing.
Found in Southeast Asia
Regions
Biomes
Appearance
Male
Female
Juvenile
Colourmorphs
Albino male
Albino female
Albino juvenileSize & weight
Size
Nose to rump: 78 to 97 cm
Juvenile
Juvenile weight
12.5 kg
Measured as Nose to rump. The person stands 1.75 m tall for scale.
Habitat requirements
Barrier grade
Grade 3 of 5
Minimum height
3 m minimum
Climbing & water
Climb proof
Needed
Water barrier
Allowed
Water barrier size
6 m wide, 2 m deep
Habitat needs
Minimum area
Land
780 m² + 50 m² per extra animal
Climbing
120 m² + 40 m² per extra animal
Shelter
15 m² per animal
Environment
Temperature
18 to 33°C
Plant coverage
20-100%
Enclosure
Climb-Proof Habitat
Dislikes
Rain and snow
Terrain
- Short Grass 20-100%
- Sand 0-20%
- Soil 10-80%
- Rock 0-40%
- Waterlogged 0-10%
Diet and enrichment
Diet
- Leafy Greens and Vegetables
- Nutritionally Complete Biscuits
Water sources
Conservation
IUCN Red List
Critically endangered
Least concern
Critically endangered
Wild population
14,000
14,000 - 15,000 (estimated) in the wild. Rank 24 of 58 species with a known count, smallest first.
Sumatran orangutans are Critically Endangered. Their decline is primarily driven by habitat loss and illegal killing and trade. Between 1985 and 2014, rainforest cover in Sumatra fell dramatically, and still, large swatches of forest are cleared for oil-palm plantations, lumber, and other agriculture. This destroys and fragments vital habitat, preventing orangutans to find food and mates. Additionally, despite legal protection, orangutans are sometimes captured for the pet trade and killed for meat or because they are seen as pests on plantations. Their slow reproductive rate means even a few deaths have major impacts on population viability. Conservation efforts include habitat protection, rehabilitation, and community-based conservation. Orangutans confiscated from illegal trade are rehabilitated and reintroduced into protected areas. Furthermore, conservation organisations engage with local communities to promote sustainable livelihoods, reducing the pressure to convert rainforest into plantations. Global efforts raising awareness and shifting consumer demand away from palm oil, and seeking to strengthen protection against illegal logging are helping, slowly but surely, to reduce drivers of habitat destruction.
Zoopedia sketchbook
Social & reproduction
Keeper notes
Occasionally, a male and female may travel together for a time, but orangutans generally live alone, except for a mother and her young. They have far less social interaction than other ape species. However, they are still intelligent animals, and do not like complete isolation from their counterparts. They will interact if they meet, and may be friendly, avoidant or aggressive. Sumatran orangutans can mate year-round: female receptiveness is determined by a 30-day oestrus cycle. Mature, dominant males preside over large territories. They develop cheek and throat pads, and are far more likely to gain the attention of females than younger or less dominant males that lack these flanges. Dominant males often call to attract females to their territories from far away. After successfully mating, a female will be pregnant for 8.5 months and give birth to a single infant. She will care closely for her child for the first 8 years of its life. Young orangutans remain with their mothers until 10 to 11 years old, then they leave to live solitarily and establish their own home range.
Group and breeding
Group
Group size
1-6 (up to 1 male, up to 5 females)
Male bachelor group
1
Female bachelor group
1-6
Offspring dispersal
Male offspring
Lifecycle and breeding
Life expectancy
44-58 years
Age of sexual maturity
10 years
Age of sexual sterility
Death
Gestation or incubation
8.8 months
Interbirth period
104.6 months
Litter size
1
Mating system
Polygynous
Mating season
Aseasonal
Reproduction in captivity
Easy
Dominance
Male dominance
Research
Research levels
| Level | Unlocks | Research gate |
|---|---|---|
| Level 1 | Thriving Requirement 1: at least 20 objects or plants with the Climbable tag | |
| Level 2 | Thriving Requirement 2: Tool Puzzle Feeder, at least 2; Sumatran Orangutan Fact Sheet | |
| Level 3 | Release groups and release to the wild | |
| Level 4 | Thriving Requirement 3: Food Grade 2; Fertility Level 1 (+15% fertility) | Before this level: an Observation Network (Observation Platform) in Sumatra Reserve and this species released in Sumatra Reserve |
| Level 5 | Thriving Requirement 4: at least 50% native plants | |
| Level 6 | Thriving Requirement 5: Fixed Roller Feeder - Large, at least 2; Fertility Level 2 (+30% fertility) |
Researched by
Vets
Researched at
Habitat or exhibit and Research Centre
Wildlife Reserve
Sumatra Reserve
Every level of this species' research, with its unlock conditions.
Release groups
Valid release groups
| Group | Type | Animals |
|---|---|---|
| Maternal Family Group | Female group | 1 female |
| Solitary Male | Solitary male | 1 male |
Release requirements
| Requirement type | Requirement |
|---|---|
| Ecosystems Required | Flourishing Montane Rainforest |
| Ecosystems Required | Peatland |
Ecosystems
Release groups, reserve requirements and the roles this species fills.
Animal facts
- Orangutans are the only great ape species that do not live in Africa.
- Orangutan means 'person of the forest' in Malay and Indonesian, they are 7 times stronger than humans.
- Orangutans are the largest tree-dwelling animal in the world.
- Orangutans are the only ape species that live solitarily.
- Orangutans use tools with their mouths, unlike gorillas and chimps that use their hands.
Taxonomy
Class
Order
Family
Genus
Species
