Orangutans are the only great apes found on the Asian continent. Other close relatives come from Africa, including chimps, gorillas, and bonobos. Orangutans are protected in Indonesia under Law No. 5 of 1990. The IUCN has classified orangutans as Critically Endangered (Critically Endangered) because their natural population is decreasing due to hunting, trade, deforestation, and conflicts with humans. Furthermore, orangutans are listed in Appendix I of the CITES (Convention on International Trade in Endangered Species) and are not permitted to be traded in any form.
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There are three species of orangutans in Indonesia, Sumatran orangutan (Pongo abelii), Tapanuli orangutan (Pongo tapanuliensis), and Bornean orangutans (Pongo pygmaeus)
The orangutan population decreased drastically in the last 20 years. Based on PHVA analysis (Population Habitat Viability Analysis) in 2016, it is estimated that there were 71,820 individuals on the islands of Sumatra and Kalimantan, which are spread over 51 metapopulations in an area of 17,460,000 hectares.
Around 57,350 Bornean orangutans inhabit an area of 16,013,600 hectares, with the most sub-species, Pongo pygmeaus wurmbii (38,200 individuals). In Sumatra, orangutan populations are around 14,470 individuals.
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Orangutans are endangered and live in tropical forests. As an umbrella species, orangutans help to protect the tropical forest ecosystems in which they live, as well as the other species that live there. In this case, orangutans serve as "umbrellas" or "protectors" for other species as well as the environment.
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Because orangutans are the primary herbivores that disperse seeds through their feces, their presence in tropical forests helps to renew plants. Furthermore, orangutans act as both predators and prey in the tropical forest food chain, so their presence helps in the maintenance of complex ecosystems.
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Thus, protecting orangutan habitat and ensuring their survival not only helps to ensure orangutan populations in perpetuity but also helps to maintain biodiversity and the balance of tropical forest ecosystems.
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SUMATRAN ORANGUTAN (Pongo abelii)
When compared to the Bornean orangutan, the owner of the scientific name Pongo abelii has a smaller body size and brighter orange hair. This animal, known locally as mawas or maweh, can weigh up to 90 kilograms. Sumatran orangutans can be found from northern Sumatra to the western edges of Lake Toba. Furthermore, this species is found in the Bukit Tiga Puluh Landscape, which is a released population.
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The Sumatran orangutan's hair is brown, slightly orange, and appears brighter than that of its Kalimantan relatives. According to research, Sumatran orangutans primarily consume fruit. Because the fruit season in Sumatra is longer than in Kalimantan, fruit is plentiful all year.
Sumatran orangutans are arboreal animals that spend their time in trees foraging, building nests, and sleeping.
TAPANULI ORANGUTAN (Pongo tapanuliensis)
Before being classified as a new species, the orangutan tapanuli was known to the general public and scientists as a Sumatran orangutan. There is nothing to worry about because this species is distinct from Sumatran orangutans. According to genetic research, orangutans in Batang Toru have a closer relationship with orangutans in Kalimantan than with orangutans in Sumatra.
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Orangutan tapanuli can only be found in Sumatera Utara's Ekosistem Batang Toru. This species was discovered as a new species in November 2017.
The Tapanuli orangutan has a very small range, occupying approximately 132 thousand hectares in the Batang Toru landscape and several other habitats. The condition of their habitat is also divided, due to natural factors and nearby development.
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The wild population of Tapanuli orangutans is estimated to be less than 800 individuals. Consequently, it is one of the world's most endangered primates.
BORNEAN ORANGUTAN (Pongo pygmaeus)
Based on genetic studies, the Bornean orangutan has been identified as having three subspecies:
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Pongo pygmaeus pygmaeus spread in the northern part of the Kapuas River (West Kalimantan) to the northeast of Sarawak (Malaysia).
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Pongo pygmaeus wurmbii found from the southern part of the Kapuas River (West Kalimantan) to the eastern part of the Barito River (Central Kalimantan).
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Pongo pygmaeus morio is spread from Sabah (Malaysia) to the south reaching the Mahakam River in East Kalimantan.
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Physically, Pongo pygmaeus wurmbii is the largest orangutan sub-species and Pongo pygmaeus morio is the smallest orangutan sub-species among its other relatives in Kalimantan.
In Kalimantan, orangutans have many names. Some areas mention hirang, helong lietiea, kahui, kisau, kogju, kuyang, kahiyu, oyang dok, ulang, uyang paya, and maias.