People of the Forest

The word “orangutan” comes from the Malay and Indonesian words ‘orang', meaning people, and 'hutan', meaning forest. Humans share 97% of our DNA with orangutans, making the name even more meaningful.

Lonely Gardeners

Humans have such intense social hangups, we need other people.  Gorillas need other gorillas, and chimps are so volatile and socially sensitive.  The thing that differentiates orangutans is that they don’t really need other orangutans, other than to procreate. They spend months without seeing another one and they’re more than happy.  They just want to be left alone in the forest, and to eat. We call them “lonely gardeners”, because they eat all the fruit and then spread the seeds in their droppings.  That’s romanticising it a bit, because much of the time they’re starving and looking for food, but fundamentally that’s all they want to do.

Medicine

An Orangutan in Sumatra was recently seen applying medicine to its wound, which is especially interesting because the Dayak traditionally also use that same root as medicine. 

Bornean vs Sumatran

There’s been some new findings on the differences between Bornean and Sumatran orangutans.  In Sumatra there are tigers, whereas in Borneo there are no real predators, and so male and even female orangutans in Borneo spend much more time on the ground. 

The males also long call in a very specific direction. They’re not just calling randomly. They’re thinking about where they’re going in the day and so they wanna tell everybody in that direction that they’re coming.  

Mother & Baby

Orangutans have the longest inter-birth interval of any mammal.  The reason is tied to the forest, because it changes so much over long periods of time.  Some things don’t fruit for five years, some don’t fruit for ten, and so babies have to learn things over a really long period of time.  There’s a lot they might never have seen in the first five years of their life, which is why they have to spend so much time with their mothers.  There was a big mast fruit season that just happened in the forest.  There are so many fruits, so many different spiky things, and segmented things, and things that are hard to get open.  Some of those won’t fruit again for another five years.  So if a baby is born in the next three months they’re not gonna see that food until they’re almost ready to be an adult out on their own. 

When they’re really little, babies just drink milk, but they’re always watching everything that mom is doing, what she is eating, how she pulls it apart, and they’ll come and try to take a little bit out of her mouth to test it.  If mom doesn’t eat something then the babies will never know that it’s food, so sometimes it takes them a long time to learn all the things that are food. 

Female Orangutans are Philopatric

They live within their mother’s home range, sometimes for their whole lives.

Communication between Mother and Infant

New studies found the females scratch to communicate with their infants to tell them to leave and move to another area. This might be because they want to avoid attracting any predators or other orangutans. It makes sense, because they use gestures to give very subtle hints to the babies to tell them to move in a certain way. There’s a very tight connection between the two of them and they communicate in this very subtle way. If you think about it, it’s because they’re with each other for so long and the baby sometimes has not seen any other orangutan except for the mom. 

Male Orangutans going through Puberty

The most volatile orangutans are juvenile males going through puberty, changing from young males to adults. They’re not babies anymore and want to prove themselves, so they start testing everyone.  Their hair stands up, and they get goosebumps, usually because of fear or anger, or because they’ve seen someone they don’t like, but sometimes you have no idea what triggers it.  This is called piloerection, or “merinding” in Indonesian. What’s for sure is that once an orangutan decides they don’t like you, it’s forever.