ANALYSIS OF COMPOSITION, AVAILABILITY, AND UTILITIES OF ORANGUTAN’S FOOD PLANTS IN JUQ KEHJE SEWEN ISLAND, EAST BORNEO

• Main Author: Izza Dwiyanti (11514029), Evita
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/27022
• Institution: Institut Teknologi Bandung

Bornean orangutan (Pongo pygmaeus ssp. morio) is the largest arboreal mammals <br /> <br /> in the world which now critically endangered with populations in sharp decline due <br /> <br /> to habitat destruction and illegal hunting. Some orangutans live in the rehabilitation <br /> <br /> center and attempted to release to the wild. Juq Kehje Sewen Island is a secondary <br /> <br /> forest in the release area located in the conservation area of oil palm plantation, <br /> <br /> which currently inhabited by nine rehabilitant orangutans and four wild orangutans. <br /> <br /> This study aims to determine the composition of food species, analyze the behavior <br /> <br /> of food plant utilization, estimate the availability of foods and determine the habitat <br /> <br /> carrying capacity of Juq Kehje Sewen Island. Vegetation analysis was used to <br /> <br /> determine the composition and dominance of food and non-food plants. Focal <br /> <br /> animal sampling and instantaneous sampling were used to observe the behavior and <br /> <br /> daily intake of six rehabilitant orangutans. The estimation of carrying capacity was <br /> <br /> obtained from dividing food plants productivity with daily consumption of <br /> <br /> orangutans. The food plants productivity include fruit, leaves and pith. Research’s <br /> <br /> result stated there are 128 species of plants and consisted of 65 species are <br /> <br /> orangutan’s food plants. The main fruits species consumed by orangutans are Ficus <br /> <br /> sp.3, Ficus racemosa, Dracontomelon dao, Syzygium sp.1, and Averrhoa <br /> <br /> carambola. The average percentage time spent for feeding by rehabilitant orangutan <br /> <br /> in Juq Kehje Sewen Island is 39,74% with the highest diet composition is fruits <br /> <br /> (43,11%). 97,24% food source of orangutans is the result of their foraging activity <br /> <br /> in the forest, while the rest is from human giving. The highest feeding postural is <br /> <br /> feeding with sitting and hanging position. The average percentage of rehabilitant <br /> <br /> orangutan’s daily intake is 3,1 kg/day. The productivity of ripe fruits is 6,22 kg/ha <br /> <br /> per day, leaves productivity is 1,89 kg/ha per day, and pith productivity is 27,12 <br /> <br /> kg/ha per day. Therefore, the estimated carrying capacity of Juq Kehje Sewen Island <br /> <br /> is 6 rehabilitant orangutans or 3 wild orangutans.