Preliminary Result on Ranging Behavior of Orangutans Reintroduced into Jantho Sumatran Orangutan Reintroduction Station –Aceh Province

 

Author: Fitriah Basalamah1,2,5; Sri Suci Utami Atmoko2; Dyah Perwitasari-Farajallah1,3*; Ibnul Qayim1; Mukhlisin Abdullah4; Ian Singleton4; Carel Philippus Van Schaik5

  1. Department of Biology, Faculty of Mathematics and Natural Sciences, Bogor Agricultural University, Darmaga Campus, Bogor 16680, Indonesia
  2.  Biology Faculties, Universitas Nasional, Jalan Sawo Manila, Pasar Minggu, Jakarta– Indonesia
  3. Primate Research Center, Bogor Agricultural University, Jalan Lodaya II no 5, Bogor 16151, Indonesia
  4. Sumatran Orangutan Conservation Programme, Yayasan Ekosistem Lestari, Jalan Wahid Hasyim, North Sumatra, Indonesia
  5. Anthropologisches Institut und Museum, Universitat Zurich Switzerland Winterthurerstrasse 190, CH-8057 Zürich, Switzerland

Abstract

We report the preliminary results of ranging behavior of ex-rehabilitant orangutans in Jantho Sumatran Orangutan Reintroduction Station, a lowland rainforest in northern Sumatera, Aceh Province. The study is based on ranging behavior of 10 individuals (tree juvenile female, one adolescent female, one sub adult male and five juvenile male) observed follows during their first years after release. In the study site, acclimatization cages with interval released 1 – 3 months and feeding were present, six times per day for orangutans’ candidate inside. Home range size and overlap between individuals were estimated.  The home ranges of ex-rehabilitant orangutans ranged from 0.61 – 78 ha, with an average   day   journey   length   of   428-1280   meters.   Home   ranges overlapped varied between 10.29 – 91.54% for females seen around the ‘first’ release point (acclimatization cage) and 4.62 – 92.30% for some males, who ranged more widely. The influence of possible ecological resources on ex-rehabilitant orangutan ranging behavior was examined by assessing the number of woody tree (1.7 – 10.7 patch/km), ficus (0 -4.2 patch/km) and lianas (0.5 – 12.3 patch/km) were consumed as food patch. Presences of acclimatization cage and food provisioning might be given their effect on ex-rehabilitant orangutan ranging behavior.

 

Keywords: Pongo Abelii, Reintroduction, Home Range, Daily Range, Food Patch.

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