Knowing how to compete with other orangutans while foraging is one of the most important skills an orangutan needs to survive in the wild. Each individual orangutan eventually learns about this, sometimes the hard way! So how has Desi, a 19-year-old female orangutan who resides on Juq Kehje Swen Island, learned about foraging competition? Check out this story.
Desi, the only orangutan currently undergoing rehabilitation on Juq Kehje Swen Island in East Kalimantan, has fruits and vegetables delivered to her to supplement her diet. The food is delivered to the island by the island monitoring team once daily, usually in the afternoon.
Juq Kehje Swen Island, located about 10 kilometres from the Kehje Sewen Forest, is a man-made 82.84-hectare forested island made possible through a collaborative effort between the BOS Foundation and PT. Nusaraya Agro Palm Oil (NUSA). The island is currently used to accommodate orangutans undergoing the pre-release stage of rehabilitation.
Since the island is surrounded by a river, food is delivered to Desi by motorised long boat, locally known as a ces. When Desi hears the sound of the approaching ces engine, she will immediately rush to the feeding platform and wait for the technicians to unload the food delivery.
However, there are often prying eyes spying on the team and Desi, a group of wild and bold macaques. If a team member, or Desi, lets their guard down even for a moment, the macaques will quickly rush over to steal the food intended for Desi.
Despite being unable to stop all of them, Desi will safeguard her food as much as possible, especially if there are any mangoes - her favourite fruit! Initially, the monitoring team didn’t wait around for Desi to finish eating, as she is not a picker eater and would eat all the food given to her. Now, given the frequent stealing of Desi's food, the team has changed tactics and they will only leave the island once Desi has actually eaten all of her food.