Abstract
Lao leaf monkeys (Trachypithecus (francoisi) laotum) are endemic to a small area of central and, marginally, north Lao. They are known from a few, mostly vague, historical records. We here present a detailed examination of the distribution of this little-known taxon and discuss its conservation status. Surveys since 1992 show its range to be centered upon the karst-dominated Phou Hin Poun National Protected Area (NPA), Nam Sanam Provincial Protected Area, and the southern part of Nam Kading NPA. The known range encompasses <2000 km², within which occurrence is patchy, reflecting habitat availability. The taxonomic identity of leaf monkeys plausibly of this group reported to the north of this area is not known. In the south of Phou Hin Poun NPA, village reports that the monkeys have black heads are corroborated by the few sightings; their taxonomic relationship with typical Trachypithecus laotum is unknown. In the mid–late 1990s large populations remained and individuals were easily seen. There is no apparent large-scale threat to their habitat. There has been no significant reassessment of status since the late 1990s, nor is there any active conservation action in place. Although the monkeys are to a significant extent protected by the arduous terrain, this cannot be relied upon indefinitely: Trade-directed hunting, although apparently limited in the 1990s, is a potential threat that could cause rapid population declines. Local traditions offer significant starting points for conserving these monkeys.
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Acknowledgments
Permission to conduct the surveys that generated the information in this article was provided by the Centre for Protected Areas and Watershed Management of the Department of Forestry, Ministry of Agriculture and Forestry, Lao Peoples’ Democratic Republic. Particular thanks are due to Chanthaviphone Inthavong, Venevongphet, Klaus Berkmüller, Bouahong Phantanousy, Bouaphanh Phantavong, and Bruce Jefferies for their assistance. Sinnasone Seangchantharong, Field Manager of Phou Hin Poun NPA, was helpful in many ways. Rob Tizard, Mark Robinson, John Pilgrim, John Parr, Khamkhoun Khounboline, Chris Hallam, Roland Eve, Tom Evans, Jonathan Eames, and Stijn De Win provided records and information about the areas. None of the work would have been possible without the enthusiastic assistance of our counterparts and the input of Khamkhoune Khounboline, Chainoi Sisomphone, Boonhom Sounthala, and Somlor Vongsamphan over several years. Utai Dachyosdee helped create the map. The surveys were organized and funded largely through the Wildlife Conservation Society and World Wide Fund for Nature–Thailand, with additional funding from the Global Environment Trust Fund, through the Forest Management and Conservation Project. We thank 2 anonymous reviewers for valuable comments.
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Steinmetz, R., Timmins, R.J. & Duckworth, J.W. Distribution and Conservation Status of the Lao Leaf Monkey (Trachypithecus (francoisi) laotum). Int J Primatol 32, 587–604 (2011). https://doi.org/10.1007/s10764-010-9489-0
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DOI: https://doi.org/10.1007/s10764-010-9489-0