In the past, orangutans lived throughout Southeast Asia, as much as southern China, and were found on the island of Java and southern Sumatra. Orangutans are currently found only on the islands of Borneo and Sumatra, and the Sumatran species are limited to the northern a part of the island. Sumatran orangutans are divided into 9 separate populations, all of that are present in the Indonesian provinces of Aceh and North Sumatra. Bornean orangutans are far more widespread and occur, amongst others, Kalimantan, Sabah and Sarawak. No everlasting orangutan populations have been reported in Brunei.
Orangutans on each islands mainly inhabit swamp-peat forests, tropical heathlands and mixed dipterocarp forests at altitudes lower than 1,000 meters (3,281 ft) above sea level. It has been shown that the population density of orangutans positively correlates with the extent of fruit availability. This signifies that in forests where there’s a greater abundance of fruit and roughly drastic periods of seasonal fruit shortages, orangutans live in much higher densities than in other forests.
In general, because Sumatran forests look like more productive than those in Borneo, Sumatran orangutan populations are denser than Bornean orangutan populations. Orangutans living in peat forests live in higher densities than in other sorts of forests.
There are three species of orangutans – Bornean, Sumatran and Tapanuli – which differ barely in appearance and behavior. Bornean and Sumatran species have shaggy reddish fur, Sumatran orangutans have longer facial hair.
Sumatran orangutans have also been reported to have closer social bonds than their Bornean cousins.
The Sumatran orangutan is nearly exclusively arboreal. Females practically never travel on land, and adult males rarely accomplish that. This is in contrast to Bornean orangutans, especially adult males, which usually tend to come right down to the bottom.
In November 2017, the looks of a 3rd species of orangutan was announced. Numbering not more than 800 individuals, the Tapanuli orangutan is essentially the most endangered of all great apes. This latest, third species lives in North Sumatra, but is genetically and behaviorally different from the opposite two species.
An international team of scientists described the brand new species within the journal Current Biology. The Tapanuli orangutan (Pongo tapanuliensis) is distinguished from other orangutan populations based on morphological and genomic evidence. The latest species is endemic to a 475-square-mile upland forest within the Batang Toru ecosystem in Sumatra and is believed to have been isolated from other orangutan populations for 10,000 to twenty,000 years.
Orangutans mainly eat ripe fruits, young leaves, bark, flowers, honey, insects, vines and inner shoots of plants. One of their favorite foods is the durian fruit, which has a really strong smell and tastes a bit like sweet, cheesy garlic cream. Cultivated durian known as the “king of fruits”, probably due to its large size, strong smell and strange taste. Orangutans eat wild durians within the forest, but in addition they climb on cultivated durians in people’s gardens. Orangutans shed the skin, eat the flesh and spit out the seeds, acting because the predominant seed dispersers of this fruit, in addition to many others. In some regions, orangutans sometimes eat the soil, thereby ingesting minerals that will neutralize large amounts of toxic substances tannins and acids of their mainly vegetarian eating regimen. In Sumatra, orangutans sometimes eat slow lorikeets, dragging them out of the holes where these small, nocturnal animals monkeys sleep in the course of the day.
