Food preferences of Bornean orangutan in Lamandau Wildlife Sanctuary, Central Kalimantan

The Bornean orangutan ( Pongo pygmaeus wurmbii ) is one of the world’s most endangered primates. Orangutan food is highly varied, depending on its habitat. This research was conducted in Lamandau Wildlife Sanctuary, aimed to identify Bornean Orangutan food, and estimate their food preferences. The research was conducted on February-March 2020, by following 5 rehabilitated orangutans for 195 hours by 2 observers. Using Jacobs preference index (D i ), food were categorized as highly preferred, preferred, less preferred, and not preferred. There were 33 tree species (18 families) consumed. Oorangutans also consumed insects, lianas, mushrooms, herbs, soil, and some additional food provided by the Wildlife Sanctuary Manager. Parts of tree selected as the most preferred food are fruits (73.3%), they also eat other parts of the tree including young leaves, flowers, bark, and shoots. Highly preferred food for Orangutans were ‘katikal’ ( Ochanostachys amentacea; fruit, D i 0.95), ‘gandis’ ( Garcinia parvifolia; fruit, D i 0.83), ‘kekupui’ ( Sarcotheca diversifolia; young leaves, D i 0.78), and ‘malukan’ (fruit, D i 0.56). Other trees selected for food were categorized as preferred food (6 species), less preferred (11 species) and not preferred food (7 species). Other 5 species were uncategorized due to a lack of data.