Orangutan is the only member of the world’s great apes family in Asia. There are two species of orangutans, the Sumatran orangutan (Pongo abelii) distributed over Sumatera Island and the Borneaen orangutan (Pongo pygmaeus) distributed in Kalimantan Island (Borneo). The other three species of great apes can be found in Africa: chimpanzee (Pan troglodytes), the gorilla (Gorilla gorilla), and the Bonobo (Pan paniscus). Orangutan are belongs to the order of Primata and the Ponginae. Based on research in genetic, morphology, ecology, behavior, and life history, the Sumatran orangutans are proven to be different from their Borneo relatives (Delgado & van Schaik, 2000, Groves, 2001, Zhang et al., 2001). The Sumatran orangutan and Borneo orangutan were geographically separated at least since 10,000 years ago, when the increase of sea levels occured between both islands. The Borneo orangutan is classified into 3 sub-species (Groves, 2001; Warren et al., 2001), namely: Pongo pygmaeus pygmaeus, ranging from northwest Kalimantan (Betung Kerihun and Lake Sentarum National Parks, as well as the surrounding area) north of Kapuas river, across the east of Serawak state (Malaysia); Pongo pygmaeus wurmbii, ranging from southwest Kalimantan to the south of Kapuas river through the Barito river; and Pongo pygmaeus morio: ranging from Sabah and eastern Kalimantan until the Mahakam river. Physical characteristic:
- The Borneaen orangutan (Pongo pygmaeus) possess a larger body, has a dark or reddish brown, rare and short hair, and they have reddish or greenish spots during infancy;
- The Sumatran orangutan (Pongo abelii) has a smaller body, has a bright or orange hair and their arms are longer than feet;
Generally, male orangutan has cheeckpads which get larger as they grow and its body is twice bigger than a female orangutan with the weight ranges from 50-90 kg. Habitat:
- The Habitat of orangutan is lowland tropical forest, swamped forest or hill forests in the height of 1,500 m above see level. Currently, they inhabit remaining forests in Kalimantan and Sumatera (90%), while the rest are found in the Malaysian remaining forests (Sabah and Serawak);
- Orangutans are arboreal creatures. It means they nested above the high trees and spend more daily activities above ground.
Food and Forest Regeneration:
- Orangutans eat fruits (frugivore). They also eat leaves, flowers, and cambium. Termites and ants are part of their diet to obtain protein. For minerals, orangutans sometimes eat soil;
- Orangutans habits of eating fruit and of cruising from one tree to another plays a significant role in vegetations’ regeneration process;
- Orangutans eat meat and seeds. Edible seeds got mixed in their feces, making it possible to grow into a new plant and thus help forest regeneration;
- Orangutans also ‘eat on the way’ during their exploration between trees. They spit seeds while doing so far from the parent tree. This way, they help spread the population area of trees.
Culture and Behaviors:
- Orangutan lives in semi-solitaire environment. They do not form groups as other great apes do. They socialize with other individuals only during mating season which lasts for 2-3 weeks and -for adult females-during child care period. Orangutans gave birth to only one child per delivery, after 5-8 months of pregnancy. Orangutans may live up to 45-50 years old;
- Similar to humans, orangutan female parents take care, protect, and nurture their child until they can live independently off the mothers;
- Most of their daily activities performed on the canopy of large trees. They tend to explore the forest using tree branches. They actively use all the four motion arms -hands and legs- in doing that;
- Orangutans built their nest before sunset. Their nests are made in the divergent branch and equipped with folded tree branches and leaves;
- Adult male orangutans can produce a very loud long call that can be heard from 3 km away. The voice is intended to challenge other adult male orangutans in the area or to mark his territory.
Population: According to the data released by the International Workshop on Population Habitat Viability Analysis (PHVA)-2004, orangutan population in Kalimantan reaches 57,797 individuals. While in Sumatra, the number is 7,501 individuals. Conservation status:
- International Union for Conservation of Nature and Natural Resources (IUCN/2004) put orangutans in the category of Critically Endangered for the Sumatran orangutans and Endangered for the Borneaen orangutans;
- CITES Appendix 1.
- Official regulations:
- Regulations of Wild Animals Protection (Peraturan Perlindungan Binatang Liar) #233/1931;
- Law (UU) #5 year 1990;
- Ministry of Forestry Verdict Letter (SK Menhut) June 10, 1991, #301/Kpts-II/1991;
- Government Regulation (PP) #7, 1999.
IUCN estimated that in one or two decades, orangutans will face extinction. This will likely to happen should there be no serious effort taken into account in avoiding it. (Source: Dr Sri Suci Utami Atmoko, Book: Di Ambang Kepunahan [In the Face of Extinction], and PPS Ragunan)