﻿Taxonomic and genetic assessment of captive White-Handed Gibbons (Hylobateslar) in Peninsular Malaysia with implications towards conservation translocation and reintroduction programmes.

Millawati Gani,Noor Azleen Mohd Kulaimi,Frankie Thomas Sitam,Nur Maisarah Abd Rahim,Chew Cheah Zheng,Jeffrine J Rovie-Ryan,Aida Nur Atiqah,Ahmad Azhar Mohammed

doi:10.3897/zookeys.1076.73262

Abstract

Conservation translocation and reintroduction for the purpose of repopulating and reinforcing extirpated or depleted populations has been recognised as an important conservation tool, particularly for gibbon conservation in the immediate future. Feasibility assessments involving multiple factors, including taxonomic and genetic assessment of rescued and captive gibbons, are imperative prior to translocation and reintroduction programmes. In this study, we attempt to determine the subspecies and origin of captive Hylobateslar, White-handed gibbons, from Peninsular Malaysia to assist in future translocation and reintroduction programmes. A total of 12 captive and rescued H.lar samples were analysed using the control region segment of mitochondrial DNA. Sequence analyses and phylogenetic trees constructed using neighbour-joining, maximum likelihood, Bayesian inference, and network methods congruently differentiate all 12 captive individuals used in this study from other H.lar subspecies suggesting that these individuals belong to the H.larlar subspecies. In addition, two populations of H.l.lar were observed: (1) a southern population consisting of all 12 individuals from Peninsular Malaysia, and (2) a possible northern population represented by three individuals (from previous studies), which might have originated from the region between the Isthmus of Kra, Surat Thani-Krabi depression, and Kangar-Pattani. Our findings suggest that the complete control region segment can be used to determine the subspecies and origin of captive H.lar.

Highlights

Small apes, known as lesser apes, consist of 20 species of gibbons inhabiting Southeast Asia which are grouped into four extant genera: Hylobates, Hoolock, Nomascus, and Symphalangus
Haplotype mapping revealed that the 12 individuals of H. l. lar from Peninsular Malaysia are unrelated with an haplotype diversity (Hd) of 0.99
A total of 1030-bp of the complete control region (CR) of mitochondrial DNA (mtDNA) was successfully obtained from all 12 samples used in this study using the newly designed pairs of oligonucleotides

Summary

Introduction

Small apes (family Hylobatidae), known as lesser apes, consist of 20 species of gibbons inhabiting Southeast Asia which are grouped into four extant genera: Hylobates, Hoolock, Nomascus, and Symphalangus. In Peninsular Malaysia, H. lar is distributed throughout except for a narrow region between Perak River (State of Perak) and Muda River (State of Kedah) that is inhabited by the congener, H. agilis (Brockelman & Geissmann 2020). Both species are categorised as ‘Endangered’ by the IUCN Red List of Threatened Species (Brockelman and Geissmann 2020; Geissmann et al 2020) and are ‘Totally Protected’ under the Wildlife Conservation Act 2010 enforced in Peninsular Malaysia. Illegal hunting for the food and pet trade as well as habitat loss due to anthropogenic activities (forest clearing for development and agriculture) have been identified as the major causes of the decline of more than 50% of H. lar populations in the wild across its range (Brockelman and Geissmann 2020)

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Conclusion