Things They Do
Darwin in a young independent male living in Kutai National Park, East Kalimantan Indonesia. At a guess, he's about 8 years old. He's even tempered, very concentrated on eating, and not much bothered by observers—for the first couple of days. After that, he gets fed up with our presence and quickly gives us the slip. We got fed up with losing him (and embarrassed at regularly losing) so we concocted a new strategy to enable us to follow him longer. When we next met him, we started by following him normally with two familiar observers. That went fine: Darwin ate normally, in the trees, all day. So the next days we sent 4 observers, to cover more escape routes and track his whereabouts better.
At first Darwin didn't appear bothered by additional observers. On day 2 he came to the ground once, briefly, but moved and ate normally giving no signs of stress or intentions to disappear. On day 3, he seemed to try to hide behind leaves once, came to the ground again and headed down a hill. Down-the-hill normally gets rid of followers; it did lose observers this time too, but with their extra numbers they managed to find him again within an hour. By day 4, Darwin had had it. He made for the ground again and into a thick bamboo patch, finally heading downhill along a low trail. Observers kept him in sight until he nested for the night, but they had to crawl like lizards through the bamboo patch as Darwin kept them wandering around all day. On day 5, Darwin came to the ground in the morning, kiss-squeaked at observers in irritation, and traveled uphill through the bamboo patch along the same low trail he had used the day before. The observers followed so he went back downhill through the bamboo, along a different trail. The observers still stuck with him, so he went off-road, heading uphill through part of the bamboo patch with no trail. That got rid of them!
The moral of this story? As is often the case when orangutans and humans match wits, orangutans win. This story has a postscript. We found Darwin again two days later and resumed following with three observers. Day 1 was fine. Early in the afternoon on day 2, Darwin went right back to the bamboo and disappeared within minutes. Orangutan outsmarts humans again.