By Dr. Meredith L. Bastian
At my former wild orangutan field site, the orangutans fed on the pith of several species of rotan. It’s a spiny ground vegetation that is nasty to walk through, but orangutans survived on rotan when fruit was scarce. The largest of these species, known locally as rotan dahanen, was often consumed by orangutans for hours at a time, so I was able to get a good understanding of their techniques for opening the vegetation and getting to its succulent inner pith. I even once invited the head of the local village to eat soup that we made from this pith in the hopes that he would see that the forest has many useful resources and perhaps it wouldn’t eventually be burned and converted into a palm oil plantation.
As it turned out, the village head and the other villagers who came to eat rotan soup all
loved it. They seriously considered trying to harvest some of the vegetation for this purpose in the future, although a few years after my departure the site was burned down, presumably in an attempt to convert the land for local agricultural pursuits.
One day when I was watching Suni, the biggest of the flanged males ranging within my study site, I saw him bite the base of a big stalk of rotan dahanen. Clear water came flowing out from the vegetation and he drank it. A few weeks later one of my field assistants and
I ventured far out of the transect system following a big male – too far, we realized, after we both drank all of our water and became severely dehydrated. A search party eventually came looking for us when we didn’t arrive back at camp at a reasonable hour, but just at the point when my assistant and I had nearly given up trying to find our way, I remembered Suni drinking water from the base of a rotan stalk. So, I took my machete and cut into a large piece of rotan. Sure enough, fresh water came flowing out, and my assistant and I were able to replenish our water supply. What I learned from Suni about the rotan stalk was the most memorable gift I have ever received from an orangutan.