THE IMPORTANCE OF CONSERVING ORANGUTAN HABITAT
Orangutan Day is celebrated every year on August 19th!
Right after the release on April 24, 2012, the Monitoring Team immediately started to work and follow Mail and Lesan. These two were pretty quick! By midday they traveled all the way outside the transect area. But as the sun started to set, they moved back closer to their original release area, near a fruiting langsat tree (Lansium domesticum). And at 5.30 PM, not far from the riverside, they built their nests on the same tree about 30 meters above the ground. The Team observed that on this first day of freedom, Mail already ate 21 types of forest food, while Lesan had around 16 types.
So far, Mail and Lesan were always together. When they were in Forest School 3, Lesan always took the lead. But interestingly, Mail now takes his turn and Lesan follows him everywhere.
Once, Lesan was eyed by an eagle while playing in the trees. It seemed that she had played too close to the eagle’s nest. Realizing danger, Lesan immediately made a lot of noise and showed real anger to the bird, indicating a good response to threats.
Unlike Mail and Lesan, Casey did not travel very far. After her release, she went to a nearby hill to forage. Casey always stopped for a long time in one tree, enjoying the forest and eating forest fruits before swinging to the next tree. Although she didn’t eat as many types of food as Mail and Lesan, in quantity Casey did eat quite a lot. At daybreak, Casey returned to the area round her acclimatization enclosure and stayed there for a while. But when Lesan and Mail passed through the area, Casey decided to head for the hill instead. Since then Casey could be easily found around the hill, and at around 6 PM Casey made a nest in a tree right next to a fruiting Aglaia (also known as the Rangkori tree).
Initially, the Team was going to open the enclosures’ doors just in case any of the orangutans decided to sleep there, which is a common behavior in newly released rehabilitants. Fortunately Casey, Lesan and Mail seemed to be confident enough and each settled in their own nests high up in the canopy. So opening the enclosures was unnecessary and that decision was cancelled.
On the second day, the Team could not start their work in the morning as they had planned because the river was flooding. But by 7.15 AM they decided to enter the forest anyway, although it was still raining. They carefully crossed the river together and finally reached the orangutans’ location. Mail and Lesan were up and about and were no longer seen around their nests. Using radio telemetry, the Team eventually found Lesan and Mail eating together in a tree.
The two friends still traveled together, exploring new areas, with Mail as the leader. In the afternoon, Lesan and Mail returned to their favorite langsat tree and ate a lot of langsat fruits before saying good night to each other. Even though their nests were only 5-meter apart, Lesan and Mail this time chose different trees to make each of their nests.
Casey also had come out of her nest by the time the Team arrived and was seen busy eating fruits in a tree close to her nest. She still played around the hill and valley behind the acclimatization area, but she had started to explore a wider area than in the previous day. Casey also ate young rattan and a type of aromatic perennial herbs called Zingiberace. At high noon, Casey made a new nest and took a nap for more than an hour. When she woke up, she was obviously hungry again. She ate young leaves and continued eating until late afternoon before returning to her nest at the end of the day.
The next day was beautiful and sunny. The river’s water levels had returned to normal. Mail and Lesan took this opportunity to be truly adventurous as they explored and discovered many more new areas. They moved very fast and were always seen eating something while swinging from tree to tree!
Around 10.30 AM Lesan and Mail met up with Casey at the hill. By now, the Team had decided to name it “Casey’s Hill” because this was where Casey spent most of her day. Casey then joined Mail and Lesan and they played together. Suddenly, as they were enjoying a type of fruit in a tree, they were attacked by bees! They were probably too busy picking fruits and unintentionally disturbed a nearby beehive.
The three orangutans came down the trees and ran frantically on the ground, joined by our Team members who were also running all over the place to avoid beestings. In an instant, Casey, Mail and Lesan were lost from observation. The Team had to use radio telemetry again to relocate them. Signals indicated that the three orangutans were moving towards the river, so the Team spread out and traversed downstream. It was nearly an hour later that the Team found them busy eating on trees at Casey’s Hill! The navigation ability of Casey, Lesan and Mail was proven extraordinary and they all seemed to enjoy their little adventure today.