Orangutan-2: THE MOST ARBOREAL OF APES

Mar 04, 2011 08:56

…"if I had called man an ape, or vice-versa, I should have fallen under the ban of all the ecclesiastics. It may be that as a naturalist I ought to have done so". Carolus Linnaeus to Gmelin, 14.01.1774


In his book System of Nature printed in 1758, Linnaeus described orangutan ( INDEX); who he called Homo nocturnes or Homo sylvestris orang-outang) in the following way:
"Body white, walks erect, less than half our size. Hair white, frizzled. Eyes orbicular, iris and pupils golden. Vision lateral, nocturnal, Life-span twenty five years. By day hides; by night it sees, goes out, forages. Speaks in a hiss. Thinks, believes that the earth was made for it, and that sometime it will be master again, if we may believe the traveler". Not what you call a realistic description? :-)


Orangutan (Pongo) is a species of arboreal anthropoid apes, one of the closest relatives of the human beings. The name derives from Malay orang hutan which means “forest man” (orang - "man", hutan - "forest"). It’s worth mentioning that Bataks from North Sumatra use the same name not only for orangutans but also for tribes of forest dwellers, kubu, for example, and headhunters preferred orangutans' heads to those of representatives of other tribes (in fact, their neighbors rarely call orangutans this way - they have other names for this ape). Moreover, the White Rajah of Sarawak James Brook wrote that local people considered transformation of a human being into an orangutan and back possible.
Orangutans have large bodies. The height of males can be up to 1.5 meters (usually 1.4 meters though they rarely stand straight. They can be 70-90 cm when seated), body mass is up to 110 kg and sometimes even 135 kg. Females are much smaller: around 1 meter high weighting 50 kg. Muscular system is very well-developed.
Back legs are short while front ones are very long, up to ankle bones (arm span is up to 2.4 meters - 40% more than their height).
Hair growth is sparse, color depends on species and age: young Sumatrans are covered with lightly ginger and red hair, old Borneo males - with reddish black, which is quite long on the shoulders.




Orangutans have large heads with a prominent mouth area. Adult males have cheek flaps (fatty and connective tissue) on both sides of the face and throat pouches located near their vocal chords that make their long calls resonate through the forest.


Adult males have whiskers and beards.




The age of maturity for females is approximately 8-12 years, for males - 14-15 years. Their lifespan is more than 30 years, often even 50 (both in the wild and in captivity. The famous record in captivity is 57 years).
Orangutans spend nearly all of their time in the trees moving from one branch to another using their very long hands and legs (second pair of hands? As there is almost no difference…


…legs’ thumbs can be curved and set opposite other fingers - a “device” for gripping onto branches


Orangutans move as experienced mountain climbers do: always having three points of support:


One more peculiarity - less restriction in the movements of their legs than humans and other primates which allow orangutans to hang like this…




… and youngsters can even hang head over heels…




Orangutan’s thumbs are a bit shorter than thumbs of other primates - so they won’t break while climbing...


Nevertheless orangutans can hang using just one hand for quite a long time…
Orangutans are so much used to living in the trees that they usually drink water from the leaves, hollows or they can just lick rain drops from their bodies.
In very rare cases when coming down to the ground they walk using all four limbs.




Every night orangutans build sleeping nests from branches and foliage to prepare an elastic platform.


Orangutans mostly eat fruits (the favourite ones are durian and longan), leaves…


…and even bark. However they are not strict vegetarians like gorillas, and sometimes they eat insects, bird eggs, and even chicks or slow lories. Moreover, milk and nuts are also included in their diet.
Orangutans can’t swim (it’s difficult anyway with such long and heavy arms). However when staying with people for quite a long time they can adopt their behavior and even stop being afraid of water. Sometimes it causes accidents as it’s absolutely not possible for orangutans to learn swimming.
One more unique feature is amazingly mobile mouth which is used by orangutans for manipulating different objects.






Translated by Maria Myutel

To be continued

kalimantan, fauna

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