Friday, September 21, 2012

Beware Those Crazy Ground Apes

By now, most people know that Jess is off monkeying around in Borneo. But what am I actually getting up to day in and day out? Well, it's taken me some time to get to the bottom of this riddle myself, but I've finally worked it out. Basically, I am here to play hide and seek with the orangutans. Usually, the auburn apes like to do the hiding and I try to find them before it gets dark. If they win, I go home and count to eight hours of sleep before trying again. But if I win, I get to follow them around the forest all day! 

This bold little girl gets bored of hiding all day - she'll come close and try to push down a tree nearby to get your attention.
© Jess Stitt/OuTrop 2012

Miraculously, this game of ours lines up with the two main activities I am assigned to do here in camp: Mencari and Menikuti.

Mencari (to search) involves walking slowly along transects cut through the forest, with lots of pauses to listen for orangutan sounds. The acoustic clues include tree swaying, branch breaking, and snag crashing - which all happen to sound like the wind when it gusts through. So it also helps that the orangutan is a messy eater: dropping lots of fruity bits from the canopy onto the dry leaf floor below, chewing loudly, and "popping" the seeds of certain fruits (they use their massive jaw strength to break open a seed and access the tasty nutrient-rich core). When they go a-hunting for rayap (termites), they make sounds strangely similar to someone tearing apart rotten wood… likely because  they are using their impressive upper body strength to tear apart rotten wood. And push down big dead trees. As such, it's usually best not to stand too close when they're binging on invertebrates.

The whole family goes wild for a big dead tree feast ful of termites! Even the littlest learns how best to pick them out of the wood. (Females pictured, from top to bottom: Georgia, Gracia, & little Gretel)
© Jess Stitt/OuTrop 2012

Menikuti (to follow) starts once the jig is up and we've tracked down/stumbled upon an orangutan in the woods. A team of observers (usually two humans) will follow the individual all day, taking data on the activity and location of the orangutan every five minutes. This is the heart and soul of the orangutan behavior project, and it (usually) is as fun as it sounds to follow a wild orangutan around the jungle all day. There are endless awesome ways of traveling through the treetops to witness, a bit of quadrupedal walking on the ground to try to keep up with, lots of feeding on fruit and flowers (to sample), and every once in a while a social get together! The juveniles will play together and sometimes the adults join in - swinging upside down, grabbing at the young hooligans, and play-biting each other. And you never know who will show up to hang out: maybe an aunt, perhaps a cousin or two, or why not a big flanged male to really stir things up? By the end of the day, when all the feeding and moving and playing is done, and the sun is setting over the equator, orangutans will go their separate ways and clamber up a tree to build themselves a night nest. Expertly engineered, they pick specific tree species with just the right amount of bend to their branches. Some of the good ones have really big leaves that make for great padding. There are a few females here who like to "sing" to themselves while they work, blowing raspberries as the fold and snap and twist the branches. (I just read a paper all about the awesomeness of orangutan nest building recently, let me know if you want to have a nerdy conversation about arboreal architecture!)

Once the nest is built and the simian is done singing and snug in their swaddling, we observers are free to head home. We mark the tree where the nest's been built, to return to again in the morning. Orangutans tend to be up from sunrise until nearly sunset and, as it happens, those two are equidistant from each other year-round here at the equator. So 12-hour days are common for nest-to-nest follows; ample time to amble with such amiable acquaintances. 

An unflanged male turning the tables to observe us. I bet we make a fascinating study species.
© Jess Stitt/OuTrop 2012

I often find myself wondering what the orangutans think of us as they peer down upon the hairless hominids who always seem to struggle stepping through the swamp and brambles on two legs. Why us crazy ground apes don't just shimmy up the nearest pohon (tree) is probably beyond our graceful great ape cousins.

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