Orangutan

Did you know that animals, other than humans, are born with the capabilities to think and reason? Yes, there are a few such animals, and the Orangutan animal is one such species. An orangutan monkey is the largest arboreal mammal that lives primarily on the trees. Orangutans are famous for their distinctive red fur and characterized by powerful, long arms and have great grasping skills with feet and hands (shaped like hooks), allowing them to move around freely on the trees. So, you must be wondering what is orangutan meaning?

Orangutans are the closest relatives of the human race, and these great docile apes share 96.4% of our genes which gives them a very high intelligence level. 

Let us have a Quick Look at Some of the Basic Facts About Orangutan:

• Commonly Called - Orangutan

• Scientific Name or Genus - Pongo

• Class - mammals

• Order - Primates

• Family - Pongidae

• Species - Sumatran Orangutan (abelli), Bornean orangutan (pygmaeus), and tapanuli orangutan (tapanuliensis)

• The Average Lifespan of Orangutan in the Wild - 30 to 40 years

• The Average Lifespan in Zoos - up to 59 years

• Diet - Omnivore

• Size - When they stand, they measure around 4 to 5 feets

• Weight - Between 73 to 180 pounds

• Maturity Age - females 12 years, males 15 years.

• Gestation Period - 8 to 10 months

In this article, we will learn more about these interesting orangutan species, different species of orangutan monkeys,  few differences between male orangutan and female orangutan, and other essential facts about orangutans.

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What is an Orangutan? 

Orangutan meaning in Malay is “people, person, or man of the forest”. Few lucky ones amongst us might have seen an orangutan in the wild. However, most of us have seen them only on television as these creatures live in highly remote areas which are still untainted by human civilization. 

These red and shaggy apes are found deep in the swamps and tropical forests in the Southeast Asian islands of Sumatra and Borneo. The gorilla orangutan is the only great ape that exists in Asia. All the other great apes, namely chimpanzees, gorillas, and bonobos, are all found in Africa. 

Orangutans spend most of their time swinging on the trees, and while on the ground, they walk on all fours. Fruits make up half of their daily diet, and apart from that, they eat nuts and many parts of plants and trees like its barks. Once in a while, an orangutan also eats certain insects like termites or ants and eggs of birds. For their drinking water needs, orangutans find water in the trees (on leaves, hollows, etc.), or they also drink up water that gets stuck to their own furs after rain falls on them. 

At night time, Orangutans bend branches down in forks of trees that are high off the ground. This forms a comfortable mattress for them made up of leaves and twigs. On rainy days orangutans add a roof built from additional tree branches so that they remain dry even if it rains.

From all this, we can gather that trees are the most vital element to the existence of an orangutan. Deforestation and cutting down trees have led the orangutan species to land on the endangered species list. The significant human impact which put orangutans on the endangered list happened in the last 60 years.

Main Characteristics of an Orangutan 

Though orangutans come in different species, there are certain features that are common to all the varieties of orangutans found in the world. Some of the salient characteristics of orangutans are listed below:

• Their gray bodies are covered mainly through long and flowing reddish hair.

• They have a sturdy body with a flexible pelvis, bowed legs, and a thick neck.

• The arms of an orangutan are longer than its legs, and it reaches almost to the ankles when an orangutan monkey stands up. Their hands measure approximately 7 feet or 2 meters and are longer than their bodies.

• As with other apes, a gorilla orangutan does not have a tail.

• Orangutans live mostly on trees, and they are equipped with powerful hook-shaped hands which can easily grasp branches of trees.

• If a baby orangutan, following its mother, reaches a gap between trees that is too long for the baby to navigate, the mother creates a living bridge so that the child can scamper across.

• At times few heavy male orangutans are unable to find branches that are strong enough to hold their heavyweights. In such cases, they climb down to find the next suitable tree.

• When on the ground, orangutans look pretty awkward with their arms which look like crutches.

• Orangutans mostly live at low densities, and they are unique apes since they are largely solitary. Once they mature, male orangutans mostly live alone, and female orangutans live with their immature offsprings.

• Orangutans are skilled tool users, and they can strip leaves out of twigs to use them for reaching holes and finding termites to eat.

• They are the biggest fruit-eating animal on the earth.

• Orangutans have adapted with humans for more than 70,000 years from the time modern humans made their homes in the wet tropics.

• Wild orangutans possess great communication skills, and research at the University of Texas found that they have 11 vocal signs and 21 types of physical gestures for interaction. They have high responsiveness to communication, and they respond to gestures in less than a second in 90 percent of communications.

• A male orangutan is twice in size as a female orangutan.

• Male orangutans have two types which are flanged and unflanged. Flanged male orangutans have very prominent cheek pads (known as flanges) and a huge throat sac that can make loud verbalizations called “long calls”. Flanged male orangutans have long coat-like dark hair on their back. The unflanged male has physical characteristics which are similar to an adult female orangutan. 

• Both unflanged male and female orangutans can reproduce, and an unflanged male orangutan can change to a flanged orangutan (for reasons that are still unknown).

History and Decline of Orangutans 

Orangutans have coexisted with humans for as long as 70,000 years. Orangutans were quite widespread and abundant around the Pleistocene period (around 12,0000 years ago). One can find their teeth remains very easily in China, Indochina, Thailand, Java, Southern Sumatra, and Vietnam. This suggests that prehistoric hunters picked on orangutans easily. 

Around 20,0000 years ago, there was a significant decline in the number of orangutans worldwide, which resulted in restricted distribution with low densities. This was way before mass deforestation in the past century. There is evidence from fossils, genetics, and archaeology that the reasons for such a steep decline could be changing climate along with the human role. The arrival of humans and the advances in their hunting techniques (like projectile weapons, blowguns, and later guns) go hand in hand with the decline of orangutans. The ancient humans wiped out orangutans much like they damaged other species like giant ground sloths, woolly rhino, and many other Pleistocene megafaunas. The orangutans who survived molded their behavior to avoid the human threat. One such result was their retreatment into the thickest forests to get out of sight of human hunters.

Currently, Orangutans live only on two islands which are northern Sumatra and Borneo. Between 1999 and 2015, there was a decline of 50% in the number of orangutans in Borneo. In these 16 years, around 100,000 orangutans were lost.

The adapting abilities of orangutans are still present in them, which is why they have survived against all odds. As per some recent studies, orangutans can survive well in logged forests, can also inhabit fragmented forest landscapes which are dominated by crops like oil palm. But orangutans still do need access to natural forests. In the absence of their favorite and preferred fruits (which are ripe fruits like lychees, mangosteens, and figs), orangutans have adapted themselves to survive by eating a wide variety of fallback foods such as tree barks.

Types of Orangutans 

We now know that Orangutans are found only in Borneo and Sumatra, but the orangutans found in these two regions differ slightly in their appearances and behaviour. Apart from Bornean and Sumatran orangutans, a third species of this mammal was announced in November 2017, the Tapanuli orangutan, which has only 800 species in existence. Let us take a close look at these three types of orangutans, their similarities, and their differences.

1. Sumatran Orangutan - The other name for these is pongo abelii. These live in Sumatra, and though they also have red-colored hair like the ones in Borneo, their hair is lighter in color, and facial hair is longer than their counterparts in Borneo. The Sumatran adult male orangutans have cheek pads (also called flanges) that form rigid half circles on both sides of their face. Both male and female orangutans develop a beard as they mature. As compared to their Bornean cousins, Sumatran orangutans are known to form closer social bonds with each other. Sumatran orangutans earlier lived all through Sumatra and Java, but now they exist only in the north of the island of Sumatra in Indonesia. Right now, close to 14,000 Sumatran orangutans live in the wild.

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2. Bornean Orangutan - The other name for these orangutans is Pongo pygmaeus. They live in Borneo, and the adult male orangutan of this area is characterized by very large flanges and a huge throat pouch. The hair of these orangutans is much shinier than Sumatran ones, and Bornean female orangutans rarely grow a beard. With respect to the body, a Bornean orangutan is more heavy-set than a Sumatran orangutan. They mostly live in lowland rainforests and swamp, tropical, and mountain forests on Bornean island. There are approximately 104, 000 Bornean orangutans living in the wild.

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3. Tapanuli Orangutan - Also called Pongo tapanuliensis, these orangutans are the most endangered species amongst all orangutans. They are found in the three tapanuli districts of North Sumatra, Indonesia, only in the upland forest in the Batang Toru ecosystem (within a radius of 475 square miles). It is a new species of orangutan discovered in 1997 and described by scientists in the current biology. They are distinguished from Sumatran and Bornean orangutans owing to distinct genomic and morphological evidence. This species is believed to be isolated from other orangutans for the last 10,000 to 20,000 years. These orangutans have a skull that is slightly smaller than other orangutans and a shallower face. Their various measurements like a tooth, jaw, etc., also differ from their cousins in Borneo and Sumatra. Their hair is also shorter, more cinnamon-like in color, and frizzier. Currently, there are only 800 Tapnauli orangutans in the wild. 

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Sexual Dimorphism in Orangutans 

Sexual dimorphism denotes that a species has significant differences between their male and female varieties with respect to size and shape. The face morphology and body size of a male orangutan are significantly different from a female orangutan. 

• A male orangutan can weigh more than 200 pounds or 90 kgs while most females are about ½ or ⅓  in size. 

• Male orangutans have huge cheek pads which are also called flanges which are not present in female orangutans. 

• Male orangutans go through two phases of development. The first one is sub-adult males and the second one is fully adult males. Sub-adult males are thinner and have shorter hair than fully adult males. Sub-adult males are unflanged i.e. they do not have cheek pads and also lack the overly huge throat sacs. The adult female orangutans find these features of a sub-adult male more attractive which aids sub-adult males in obtaining female mates.

• A fully adult male has a huge throat sac that makes recognizable and notable calls that echoes through the forest. These are called long calls. Male orangutans use long calls to advertise their presence to females and also ward off other male orangutans.

• Since male orangutans are much larger than females, they travel more on the ground than female orangutans.

• Male orangutans usually lead a solitary life until they meet a female orangutan who is receptive to mating. The male orangutan then stays with the female for many days, ensuring successful mating but will soon go back to their solitary life after that.