Preliminary Gibbon Status Review for Lao PDR 2008 J.W. Duckworth December 2008 This work was carried out with funding from the Arcus Foundation. Preliminary gibbon status review for Lao PDR 2008 This review is a work in progress for the conservation of gibbons in Lao PDR. It is intended to be updated periodically. Any comment on this document, including further records, would be gratefully received by the author and by Fauna & Flora International, at the addresses below. Citation: J. W. Duckworth, 2008, Preliminary gibbon status review for Lao PDR 2008, Fauna & Flora International, Unpublished report. Author: J. W. Duckworth, PO Box 5773, Vientiane, Lao PDR Email: [email protected] Date: December 2008 For more information or to send further comments contact: Paul Insua-Cao Fauna & Flora Asia-Pacific Programme, 340 Nghi Tam, Hanoi, Vietnam Tel: +84-(0)43-719 4117 Fax: +84-(0)43-719 4119 Email: [email protected] Front cover photo of a captive young yellow-cheeked crested gibbon by Monty Sly. All views expressed within are the author’s alone unless attributed otherwise and do not necessarily reflect the opinion of Fauna & Flora International. While the authors and editors strive for rigour and accuracy in presenting this report, Fauna & Flora International make no representations as to completeness, suitability or validity of any information contained, and will not be liable for any errors or omissions. The editors and Fauna & Flora International take no responsibility for any misrepresentation of material resulting from translation of this report into any other language. 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COPYRIGHT © 2008 Fauna & Flora International www.fauna-flora.org 1 Preliminary gibbon status review for Lao PDR 2008 Table of Contents Executive Summary .................................................................................................................3 ¦ñ¤ì¸´Â©¨¹¨Ó ...........................................................................................................................6 1 Background .....................................................................................................................11 1.1 Introduction ...........................................................................................................................11 1.2 Aim of the review ..................................................................................................................13 1.3 Scope of the review..............................................................................................................13 1.4 Taxonomy, identification and general distribution of gibbons in Lao PDR .........................14 1.5 Available information base ...................................................................................................18 1.5.1 Historical records .........................................................................................................18 1.5.2 Modern information: written sources ...........................................................................20 1.5.3 Modern information: previously unpublished...............................................................22 1.6 Gibbon survey methods in Lao PDR ...................................................................................22 1.6.1 Methods of detecting gibbons......................................................................................22 1.6.2 Methods of site-level status assessment of gibbons ..................................................24 1.7 Quality control of available information ................................................................................29 2 Results and discussion ...................................................................................................33 2.1 Information presented...........................................................................................................33 2.2 Historical status of gibbons in Lao PDR ..............................................................................34 2.3 Conservation status of gibbons in Lao PDR during 1988–1999 .........................................37 2.4 Current conservation status of gibbons in Lao PDR ...........................................................38 2.4.1 Overview by region ......................................................................................................38 2.4.2 Overview by species ....................................................................................................40 2.4.3 Concluding remarks on current gibbon status ............................................................44 2.5 Threats to gibbons in Lao PDR............................................................................................44 2.5.1 Hunting .........................................................................................................................44 2.5.2 Trade ............................................................................................................................48 2.5.3 Habitat deterioration.....................................................................................................55 2.5.4 The interaction between habitat deterioration and hunting.........................................57 2.5.5 Small-population effects...............................................................................................58 2.6 Immediate conservation needs of gibbons in Lao PDR ......................................................58 2.6.1 Sites for site-based conservation ................................................................................58 2.6.2 Site-based conservation management ........................................................................60 2.6.3 Public awareness.........................................................................................................60 2.6.4 Other non-site-based interventions..............................................................................61 2.6.5 Information needs ........................................................................................................62 Acknowledgements ............................................................................................................................64 3 References......................................................................................................................67 Appendix 1. Gibbon records from Lao PDR, 1980s–present time ........................................84 Section A. West of the Mekong (genus Hylobates) ..........................................................................84 Section B. East of the Mekong (genus Nomascus) ..........................................................................87 Appendix 2. Captive gibbon records from Lao PDR ...........................................................118 2 Preliminary gibbon status review for Lao PDR 2008 EXECUTIVE SUMMARY INTRODUCTION • Lao PDR supports six species of gibbon; Indonesia is the only country with more. Asia east of the Mekong supports only crested gibbons of the genus Nomascus, of which there are four species in Lao PDR. Crested gibbons are severely threatened in Vietnam and China, and otherwise inhabit only a rather small area of Cambodia. Lao PDR can play an outstanding role in global gibbon conservation. Hence the present status review of gibbons in Lao PDR. Most of this document is a site directory, preceded by sections of how information was collected, the care taken to ensure its reliability, and the site results pooled together to determine national conservation status for each species, national-level patterns of threats and conservation, and recommendations for urgent gibbon conservation interventions. INTRODUCING GIBBONS • Gibbons are small apes and the closest biological relatives of humankind which survive in mainland South-east Asia. They are restricted to biogeographic South-east Asia, an area with generally high threats to wildlife through hunting and habitat conversion. Their family, Hylobatidae, is thus one of very few families (with many species) where all species are IUCN Red Listed as globally threatened. • For various biological reasons (e.g. low reproductive output and late maturity) gibbon populations are more heavily reduced by even quite modest levels of hunting than are many other mammals of South-east Asian forests. They are also slow to recover from population reductions. • Gibbons are arboreal so require forest, but are not as tied to old-growth stands as has sometimes been assumed. Viable populations may require areas of forest exceeding 100–200 km². It is unclear whether populations can persist in wholly deciduous forests, but they certainly occupy them near evergreen and semi-evergreen stands. There are no known Lao populations of gibbons in deciduous dipterocarp forests. Gibbon diet is mostly fruit, and in the dispersal of seeds they are important to healthy forest dynamics. STATUS OF GIBBONS IN LAO PDR • Six species of gibbons inhabit Lao PDR: Western Black Crested Gibbon Nomascus concolor; Northern White-cheeked Gibbon N. leucogenys; Southern White-cheeked Gibbon N. siki; a form of uncertain identity but morphologically close to Yellow-cheeked Gibbon