THE RELEASE RESULT OF EX-REHABILITATED BORNEAN ORANGUTAN (Pongo pygmaeus) IN GUNUNG TARAK NATURE RESERVE, WEST KALIMANTAN

• Main Author: Ester Manthalina Hut, Christina
• Format: Theses
• Language: Indonesia
• Subjects: Ilmu hayati ; Biologi
• Online Access: https://digilib.itb.ac.id/gdl/view/36839
• Institution: Institut Teknologi Bandung

Bornean orangutan (Pongo pygmaeus) tends to decline in population due to forest conversion to plantations, illegal logging and habitat fragmentation. Rehabilitation of orangutans is one way to maintain orangutan populations. This study purpose were to see daily activities, successful release, and produce standards for release of orangutans after rehabilitation. This research was conducted in Gunung Tarak Nature Reserve, West Kalimantan on June-July 2017. Observation of orangutan’s behavior was carried out by focal animal sampling method and instantaneous sampling per two minutes during the day from waking up to sleep (nest to nest). Daily behavior was recorded by DSLR camera. Two orangutans (Susi and Peni) were choosen as study objects, after one year released from rehabilitation. There are seven daily activities of two orangutans post-rehabilitation which is used as an indicator of the success of the release of feeding behavior Susi 54% and Peni 52%, Susi and Peni have same proportion for resting (17%) and traveling (9%), 1% to build a nest, interaction proportion between Susi and human’s is 1.3% while Peni is 0.6%, social behavior between Susi and Peni is 3% and 5%, and sexual behavior is not found on Susi and Peni. The success of orangutan release after rehabilitation can be determined by using the following standard: 56% eating behavior, traveling 19%, rest 18%, building 2.5% nest, social with 2% orangutans, 1% voicing, 1% sex, avoiding predators 0. 4%, and interaction with humans 0.1%. By using the standards of successful release of orangutans after rehabilitation, it can be concluded that Susi and Peni have not shown the success rate of release although they have been released for two up to three years of release.