Species Saturday

Species Saturday: new orangutan individuals

Marina, our orangutan intern, describes the exciting experience of encountering new orangutan individuals in the forest and how we go about recording the ways to recognise them in the future.
In the past few months at camp, we’ve had an exciting time out on the west side of the grid, especially in terms of finding new orangutans we haven’t come across before. Last month we discovered a ‘new’ female and her baby and in the past week we have come across another lone female, previously unseen.
Back in August, on my second 15 hour follow day in a row, accompanied by Johanna, one of the recent volunteers, we came across what was essentially an orangutan feeding bonanza. While following Indy (with infant, Icarus) and Feb (with infant, Fio) from their night nest, the day began to lull, with Indy remaining in one feeding tree for upwards of two and a half hours. As she finished up, Feb reunited with her and the two began to travel together, or so we thought. Thinking I had Indy and that Johanna had Feb, we quickly realised that another female had tagged along. Teresia and her infant Trevor had joined the gang and began to co-feed in the third Tumih tree of the day. Not so long after, another rustle was heard amongst the trees and Timi, Teresia’s sub-adult daughter appeared. The excitement levels had risen but more was still to come!
As Feb fell behind and we continued with Indy and Teresia, a not-so-subtle crash through the canopy revealed yet another female with baby, or, as she turned out to be, a rather crazy juvenile. It was at this point that I grabbed my I.D. notebook from my bag and tried to match the new arrival to the ill-drawn pictures and written descriptions within it. We managed to follow this female until she made a night nest despite the episodes of kiss squeaking and branch breaking (which is their way of signalling that they are uncomfortable with your presence). Due to her temperament it was clear that she was unhabituated and didn’t quite fit any previous descriptions. The long but exciting day drew to a close and a plan was made to follow her the next day.
With unhabituated orangutans, it’s important to determine the sex of the individual and provide a detailed description for future identification. This includes photos, and even the smallest details must be noted to give the orangutan a completely unique identity. Kelly, another volunteer, came with me for the next follow day which was a new experience for both of us. We tried to keep a balance between catching up with the female while also maintaining a little distance to ease the discomfort of having us around. Between the two of us we took notes on easily identifiable features and Kelly took photos. The infant is about five years old and female. She was quite wary of our presence but as the day progressed the aggravation became less and less. This is common during the period of habituation of primates where they need time to become used to the presence of humans. Generally the more an individual is followed the more habituated they become.
The adult female had numerous distinguishable features; a smooth edged triangular bump on her forehead, a ‘thumbprint’ indentation just behind the right-side of her maxilla and a pimple on her lip below the left nostril. These would be classed as her primary characteristics, the things that she possesses that it is likely no other orangutan in the vicinity would have exhibited. Secondary characteristics are those which, although present, do not provide enough information alone to determine if an individual is definitely the one being described. This female’s secondary characteristics include a large throat region, pale pursed lips (with wrinkles), ‘McDonalds’ shaped brow line (it was exceptionally ‘M’-like), very hairy hands, short beard on sides and underneath maxilla, ears visible and bare neck (although lack of hair can be related to health and body condition at the time). The infant also had an ‘Einstein’ hairstyle but due to age this would not be seen as a distinguishing feature.
Last week our Volunteer Coordinator, Beth, happened upon a lone female while searching in the field. With the individual sexed and photos to be looked at we are hoping to find identifiable facial features and a name to suit. 

This month we finally got around to naming the August individuals; Yana (adult) and Yoko (infant) and I most certainly hope we get the chance to see them more often. Thanks to Kelly and Johanna for helping to name the infant. It is a translation from You-ko which when written in Japanese characters means ‘sun child’. We’ve already come across the pair again on one occasion this month and I hope we get the chance to see them again soon!