Sumatran Orangutan, Most Threatened Species Guardian of Forest Regeneration

Photo Source: TribunMedan Wiki

INDEPHEDIA.com - The Sumatran orangutan (Pongo abelii) is a native Indonesian species on the island of Sumatra which is currently critically endangered (CR) based on the IUCN red list.

The International Union for Conservation of Nature and Natural Resources (IUCN) notes that over the past 75 years, the Sumatran Orangutan population has decreased by 80 percent.

Apart from the Sumatran orangutan, two other species of the Bornean orangutan (Pongo pygmaeus) and the Tapanuli orangutan (Pongo tapanuliensis) also have the same status.

Based on Law Number 5 of 1990 concerning the Conservation of Living Natural Resources and their Ecosystems, the orangutan is a protected animal under national law.

In CITES, the status of these three orangutan species is Appendix I, which means that these species may not be traded or traded.

Most Threatened Species

Among the two orangutan (pongo) species in Indonesia, the Sumatran orangutan is the most endangered, reported WWF.

This is due to the loss of forest which is the habitat of this primate. In fact, orangutans have an important role in maintaining forest regeneration, namely as seed dispersers.

Not only that, these primates are much hunted because they are considered pests by the people around their habitat. In fact, many baby orangutans are traded illegally and this is a crime.

Sumatran orangutans can only be found in the northern and central provinces of Sumatra. This species is rapidly losing its natural habitat due to forest clearing for plantations and settlements as well as illegal logging.

Currently, there are 13 pockets of orangutan population on the island of Sumatra. Of these, it is likely that only three population pockets have around 500 individuals and seven population pockets consist of more than 250 individuals.

It is estimated that six of the seven populations will lose 10-15 percent of their habitat due to deforestation so that this population will decrease rapidly.

Photo Source: Gibbon Indonesia Foundation

Physical Characteristics

Physical Characteristics Sumatran orangutans have long cheek pouches on male orangutans. Body length of about 1.25 meters to 1.5 meters.

The weight of an adult female orangutan is around 30-50 kilograms, while that of a male is around 50-90 kilograms. The plumage is reddish brown.

Adult males are generally solitary while females are often found with their young in the forest.

On average each group consists of 1-2 orangutans and both sexes have ranges of around 2-10 kilometers which overlap a lot depending on the availability of fruit in the forest.

After weaning at the age of 3.5 years, orangutan cubs will gradually become independent from their mothers after the birth of younger children.

Female Sumatran orangutans start producing at the age of 10-11 years, with an average reproductive age of around 15 years.

Behavior

About 60 percent of orangutan food consists of fruits, such as durian, jackfruit, lychee, mangoes and figs.

Meanwhile, the rest of the orangutans eat young leaves, insects, soil, tree bark and sometimes eggs and small vertebrates.

This species also not only gets water from fruits but also from tree holes.

Sumatran orangutans are known to use twigs to extract fruit seeds. This shows a high level of intelligence in the Sumatran Orangutan.

Sumatran Orangutan Population

Sumatran orangutans, citing Wikipedia, are endemic to the island of Sumatra and their lives are limited to the northern part of the island. In nature, the Sumatran Orangutan survives in Aceh Province (NAD), the northernmost tip of Sumatra.

These primates used to be more widely distributed, when they were found further south in the 1800s, such as in Jambi and Padang.

Then, there is also a small population in North Sumatra Province (North Sumatra) along the border with NAD, especially in the forests of Lake Toba.

The survey on Lake Toba found only two habitat areas, Bukit Lawang (defined as a wildlife reserve) and Gunung Leuser National Park. (*)