On November 19th, 2012, our monitoring team conducted a special mission to monitor Berlian’s activity for the whole day. As usual, our team will record every single activity precisely. Berlian is slightly different from the other orangutans, instead of exploring the forest on a fast pace; she prefers to linger to enjoy her food. After finding her morning nest, the team began to record her activity.
That morning, Berlian started her day with a breakfast of Uncaria glabra. Uncaria is locally called Gambier. Its extract powder is usually used by humans for tanning or dyeing. Her favorite parts were obviously the young leaves, young stems, and cambium bark. In addition, she also enjoyed young leaves of Etlingera Sp. (forest ginger), Calamus Sp. (bamboo), and Ficus Sp. (banyan tree). And she did all this feeding activity without even moving too far from her morning nest.
At approximately 4:25 pm, the team was surprised by the sound of a long call from a wild orangutan. Consisting 12 grumbles (breath sounds before the long call), 47 long calls and 32 bubbles (sound produced after long call as a neutralizer). This phenomenon is inline with RHOI’s team survey result a while ago describing the finding of several-abandoned nests of male wild orangutans in the area of Kehje Sewen Forest.
While the team was surprised by this sound, Berlian looked alert. She stopped eating for about two minutes. As the long calls grew louder, Berlian was getting scared. Form its loudness, the team estimated the presence of the wild orangutan was about 150 meter from where Berlian was located. The team also saw when the wild orangutan uprooted a tree (snag crash). Berlian huddled with her head between her legs, holding on to herself tightly. But after 10 minutes had passed and the long call did not come again, Berlian was back to her activities. In the next few days however, Berlian still occasionally revisited the place where the noise came from, to check things out.
According to Dr. Sri Suci Utami, a well-known primatologist in Indonesia, Berlian’s behavior is normal. Although this is not the first time Berlian experiences a long call from an orangutan (she heard it plenty of times when she still lived in Samboja Lestari), but to experience long calls in a real forest would be very different. Other factor that influences this behavior is that, an immature female orangutan like Berlian (10 years old) tends to be attracted to males who are also in their age range, without cheek pads and do not produce long calls. This is why Berlian looked very frightened when she heard the sounds of long call of the wild orangutan.
Minutes went by, Berlian was back to her activity. Once satisfied with the various types of young leaves, Berlian then started harvesting honey from a beehive on a Liana tree next to her. As expected, some of the bees became angry and attacked Berlian. The bees stroke her hand, foot and neck, but she still looked relaxed, simply enjoying the honey. Berlian was just rubbing the sting. While continuing to enjoy the honey, at 5:25 pm Berlian started to make a nest. Soon after finishing her ‘dessert’, Berlian seemed to rest in her nest.
The team then returned to Camp 103 joyously. The long call of the wild orangutan proves Kehje Sewen’s biodiversity.
Photos by: Wulan, Agus and Rio