Perilaku Makan Orangutan Sumatera (Pongo abelii Lesson, 1827) di Stasiun Penelitian Hutan Batang Toru Bagian Barat Tapanuli Utara

Abstract

The study of "Feeding Behaviour Sumatran Orangutan (Pongo abelii Lesson, 1827) at Batang Toru Forest Research Station West Block-North Tapanuli" was conducted from February to April 2013. Observation of feeding behaviour was performed using Focal Animal Sampling - Instantaneous - Ad Libitum method. The observation was done for 339,31 hours in total. Percentage of food consumed by adolescent male orangutan was comprised of 69,8% fruits, 16,2% leaves, 10,1% pith, 2,4% flowers, and 1,5% insects. Percentage of food consumed by adult female orangutan was comprised of 65,5% fruits, 15,51% leaves, 8,6% pith, 6,6% bark, 2,1% flowers, and 2,1% insects. Percentage of food consumed by juvenile female orangutan was comprised of 57,3% fruits, 15,53% leaves, 13% pith, 12,3% flowers, 1,2% bark and 0,9% insects. It was observed that Batang Toru orangutans in the study area mainly feed on fruits as the main food and alternative foods include leaves, pith, flowers, bark and insects. Foods consumed by the orangutans in the study area consists of 63 species of plant and two species of insect. The use of tool was not found in Batang Toru orangutan for extracting food. The use of tree‟s canopy for feeding by adult female orangutan is 10,19% in lower canopy, 63,82% in middle canopy and 25,97% at the top of canopy. For juvenile female orangutan, 3,81% spend in lower canopy for feeding, 62,45% in middle canopy and 33.72% in the top canopy. While adolescent male orangutan spend 5,61% in lower canopy for feeding, 78,06 % in middle canopy and 16,31% in top canopy.