Behavioral studies and veterinary management of orangutans at Bukit Merah Orang Utan Island, Perak, Malaysia

Misato Hayashi,Sabapathy Dharmalingam,Fumito Kawakami,Rosimah Roslan,Nurhafizie M Hapiszudin

doi:10.1007/s10329-018-0650-2

Abstract

The Bukit Merah Orang Utan Island (OUI) Foundation has been conducting behavioral and veterinary research on orangutans as an attempt at ex situ conservation. Since 2010, the Primate Research Institute, Kyoto University has been collaborating with OUI to promote environmental enrichment and infant rearing by biological mothers in addition to the continuous efforts of refining the veterinary management of the endangered species. In 2011, three Bornean orangutans (Pongo pygmaeus pygmaeus) were released on an island, called BJ Island, adjacent to OUI. This island is approximately 5.6 ha in size, and 635 trees belonging to 102 plant species were identified prior to their release. Behavioral monitoring of the released individuals has been conducted to evaluate their behavioral adaptation to the new environment. Two of the three released orangutans were born in the wild, whereas the youngest individual was born on OUI and expected to learn forest survival strategies from the two older individuals. One of the orangutans was pregnant at the time of release and subsequently gave birth to two male infants on BJ Island. The behavioral monitoring indicated that these orangutans traveled more and spent more time on trees following their release onto BJ Island. However, resting was longer for two females both on OUI and BJ Island when compared to other populations. The orangutans consumed some natural food resources on BJ Island. The release into a more naturalistic environment may help the orangutans to develop more naturalistic behavioral patterns that resemble their wild counterparts.

Highlights

Orangutans are the only species of great ape found in only two Asian countries, namely Malaysia and Indonesia (Delgado and van Schaik 2000; Husson et al 2009)
Many interesting behavioral patterns that allow us to make inferences about the orangutans’ cognitive development were observed on Orang Utan Island (OUI), including hitting or digging actions using an object in hand, the use of tools to touch and open the hot-wire fence, and social interactions with conspecifics and free-ranging crab-eating macaques (Macaca fascicularis)
Activity budget of three orangutans were significantly different on OUI and BJ Island

Summary

Introduction

Orangutans are the only species of great ape found in only two Asian countries, namely Malaysia and Indonesia (Delgado and van Schaik 2000; Husson et al 2009). To cease the decline in the number of orangutans, effective in situ and ex situ conservation and management techniques need to be developed and implemented through international collaborations. Compared to the African great apes that live in social groups comprising multiple adult individuals, orangutans have a relatively solitary lifestyle, with only mothers and their infants remaining in constant physical proximity and contact, the existence of loose social organization and regional variation has been suggested (Russon 2009a; van Schaik et al 2009). Considerable number of orangutan rehabilitation and re-introduction efforts has been reported from 12 projects (eight of which were active in 2009: six in Borneo and two in Sumatra), and effective protocols, as well as practical constraints have been suggested in these sites ranging within orangutans’ natural habitat (Russon 2002, 2009b; Grundmann 2006; Descovich et al 2011; Kuze et al 2008, 2012; Robins et al 2013)

Methods

Results

Conclusion