Ecology

Habitats

Nakai Nam Theun National Protected Area (NNT NPA) holds a variety of habitat types. Nakai Plateau is characterized primarily by pine forest. Mountainous areas (600-1000+ m of altitude) support mainly dry evergreen forest, which is the most common habitat type over the whole protected area. Upper mountain forest is found over 1800 m of altitude. Localised wet evergreen forest found at the border with Vietnam is of particular importance because it holds endemic species of the Annamite mountain range. At lower altitudes (below 600 m), cultivation, shrub and secondary and bamboo forest are found around villages.

Wildlife

  • Reptiles & Amphibians

Reptile and amphibian communities of NNT NPA are very little known as they remain for the rest of Laos. Current knowledge on reptiles and amphibians for the area results from opportunistic observations during surveys not specifically focussing on the group or more focussed surveys conducted in the Nakai Plateau only. An exhaustive list of this group does not exist for the area. Fifty-one different species were found (20 amphibians, 31 reptiles) in the Nakai Plateau in 2008, from which nine are globally or nationally threatened and of particular importance for their conservation. An additional five turtle species were reported but not confirmed. Of particular importance, confirmed to occur in mountainous areas are Critically Endangered Indochinese box turtle (Cuora galbinifrons), Endangered Keeled box turtle (Cuora mouhotii), Endangered Yellow Tortoise (Indotestudo elongate) and Vulnerable Impressed Tortoise (Manouria impressa). Critically Endangered Chinese three-striped box turtle (or golden turtle) (Cuora trifasciata) remains to be confirmed in the area. The demand for some species of turtles is very high; they are hunted for food or trade.

  • Fish

Fish have not been well studied over the NPA. Surveys have mainly been carried out in the plateau. Species that have been recorded from the plateau [before inundation from the hydroelectric dam] total 61 including some that were newly described to science and others endemic to the area.

  • Birds

Bird communities in NNT NPA have been well surveyed. Species confirmed in the area total 430, among which several are of global significance for their conservation value. This makes the protected area one of the most important areas for birds in Lao PDR, and Indochina. The Nakai Plateau is notably home to Endangered White-Winged Duck (Cairina scutulata), Vulnerable Wood Spine (Gallinago nemoricola), Near Threatened Lesser Fish Eagle (Ichthyophaga humilis), Near Threatened Red-Collared Woodpecker (Picus rabieri), Near Threatened Pale-Capped Pigeon (Columba punicea), Near Threatened Darter (Anhinga melanogaster) and to several species of king fishers. The protected area also holds populations of Near Threatened Crested Argus (Rheinardia ocellata), and five species of hornbills including Vulnerable Rufous-Necked Hornbill (Aceros nipalensis), Near Threatened Brown Hornbill (Anorrhinus tickelli) and Near Threatened Great Hornbill (Buceros bicornis).

  • Mammals

NNT NPA has been largely surveyed for large mammals using camera trapping and transect walk methods. The area is of National and Global significance for several mammal species. The NPA holds some of the last mammals globally discovered, endemic to the Annamite mountain range: Data Deficient Annamite Striped Rabbit (Nesolagus timminsi), Endangered Large Antlered Muntjac (Muntiacus Vuquangensis), and Critically Endangered Saola (Pseudoryx nghetinhensis) which was for the first time camera trapped in 1998 in Vietnam and a few months later in Lao PDR. A research project focusing on Saola is currently being undertaken in the NPA. A relatively large population of Asian elephants (Elephas maximus) remains in the NPA in the plateau. The last elephant survey in 2007 estimated ~ 130 individuals. The protected area is also home notably to Vulnerable Sambar Deer (Cervus unicolor), Vulnerable Gaur (Bos gaurus) and Near Threatened Southern Serow (Naemorhedus sumatraensis). Two species of bear inhabit the NPA: Vulnerable Asian Black Bear (Ursus thibetanus) and Vulnerable Sun Bear (U. malayanus). Two species of pangolins occur in NNT NPA: Endangered Sunda Pangolin (Manis javanica) and Endangered Chinese Pangolin (Manis pentadactyla). Several carnivores are found in the area, notably Endangered Dhole (Cuon alpinus), Vulnerable Marbled Cat (Pardofelis marmorata), Vulnerable Clouded Leopard (Pardofelis nebulosa), Near Threatened Asiatic Golden Cat (Catopuma temmincki), Near Threatened Leopard (Panthera pardus) and Endangered Tiger (Panthera tigris). The latter was last confirmed from the NPA in 2009 from tracks; if still occurring it is likely that only a few individuals remain. At least nine primate species live in the area: Vulnerable Pygmy Slow Loris (Nycticebus pymeaus), Vulnerable Bengal Slow Loris (N. bengalensis), Least Concern Rhesus Macaque (Macaca mulatta), Near Threatened Assamese Macaque (M. assamensis), Vulnerable Pig-Tailed Macaque (M. leonina), Vulnerable Bear Macaque (or Stump-Tailed Macaque) (M. arctoides), Endangered Red-Shanked Douc (Pygathrix nemaeus), Endangered Southern White Cheeked Gibbon (Nomascus siki), and one species of globally threatened Francois Langurs’ group (Trachypithecus francoisi [spp.]) which is localised in the area, associated with rocky cliff sites.

Threats

Despite its protected area status, several animals and trees are highly threatened in NNT for over harvesting. Rose wood is a very valuable and largely logged in the area for trade. Several animal species are hunted for local consumption or for trade. Several species are used for traditional medicine destined to Vietnam or China. The large border shared with Vietnam makes wildlife more vulnerable to hunting by Vietnamese. Snaring is the most common hunting technique used in the area.

Literature used:
Dersu 2008. C880: Wildlife program phase 1. Baseline inventory. Wildlife and habitat studies of the Nakai plateau. Vientiane, Lao PDR: Dersu and Associates for Nam Theun 2 Power Company.
Duckworth JW, Salter RE, and Khounboline K. 1999. WILDLIFE IN LAO PDR 1999 Status report. Vientiane, Lao PDR: IUCN, WCS and Centre for Protected Areas and Watershed Management (CPAWM). 275 p.
Hedges S, Johnson A, and Tyson M. 2007. Determination of the size and distribution of population of elephants, assessment of habitat and resource use, and assessment and management of human-elephant conflict on the Nakai Plateau and surrounding areas. Vientiane, Lao PDR: Wildlife Conservation Society.
Johnson A, and Johnston J. 2007. Biodiversity Monitoring and enforcement project in the Nam Theun 2 watershed (including the Nakai Nam Theun NPA and corridors linking to the Phou Hin Poun and Hin Nam Nor PA). Vientiane, Lao PDR: Wildlife Conservation Society.
Tobias J, Davidson P, and Robichaud WG. 1998. Nakai Nam Theun: can development save one of Southeast Asia’s last wildernesses? Oriental Bird Club Bulletin 28: 1-9.
Timmins, RJ and Evans, TD. 1996. Wildlife and Habitat Survey of the Nakai-Nam Theun National Biodiversity Conservation Area. Vientiane, Lao PDR: Wildlife Conservation Society.
WMPA (Watershed Management Protection Authority). 2010. Wildlife Monitoring surveys in Nakai Nam Theun NPA 2006-2010. Unpublished data. Ban Oudomsouk, Lao PDR: WMPA Office.