In general, all mammal populations were depressed below their natural abundances. Ungulate and carnivore population levels were lower than those observed in western Xe Sap in 1999 (the only previous survey) with the possible exception of Gaur. However, primate populations, although low, appeared to be relatively stable when compared with previous work and the presence of otters in both eastern and western Xe Sap NPA is encouraging. Preliminary analysis of bird surveys indicates the presence of Central Annamite species, although overall the avifauna was somewhat depauperate. The herpetofauna present is also typical of the Central Annamites. There are a wide variety of forest types present across the NPA, including one novel formation, as well as endemic and threatened species. Further botanical work is necessary, particularly in central and eastern Xe Sap.
Results to date confirm the presence of crested gibbon Nomascus sp. (possibly Nomascus annamensis), Red-shanked Douc (Pygathrix nemaeus), and a minimum of two macaque species (Macaca spp.) in Xe Sap NPA. There was no evidence of Germain’s Silver Langur (Trachypithecus germaini).
Both the February and May-June surveys reported crested gibbons calling in western Xe Sap at the majority of camp sites and were heard on the majority of mornings. Most vocalizations appeared to be from multiple groups with a maximum number of four heard at a single time. Camp sites at which gibbons detected were largely above 1,000 m. Crested Gibbons were observed outside eastern Xe Sap NPA in a conservation forest established independently by the Ban Vak Tai village and singing was heard at one of four campsites. Eastern Xe Sap needs follow-up work to determine the status of crested gibbon. Its lower elevation broad-leaved evergreen forest may be important habitat for both crested gibbons and Germain’s Silvered Langur.
The spring surveys confirmed the presence of Red-shanked Douc in Xe Sap NPA for the first time; these results have been recently published. Four different groups were encountered in western Xe Sap NPA from mid-May to early June. It is likely that this species also persist in eastern Xe Sap NPA as well.
Two macaque species were consistently reported during village interviews around Xe Sap NPA (although they did not specify them as macaques, the described appearance and behavior strongly indicate that these were both Macaca sp.):
1. A smaller, long-tailed species which often raids rice fields; and
2. A larger, shorter-tailed species that may or may not raid rice fields.
In addition, one of the survey teams observed a group of “long-tailed” macaques during the February surveys.
Identifying these macaques to species is difficult as Xe Sap NPA lies in a transition zone between morphological similar sets of macaque species as well as a known hybrid zone between Rhesus (Macaca mulatta) and Long-tailed (M. fascicularis) Macaques. At this point we believe the long-tailed species to be either Assamese (M. assamensis) or Rhesus Macaque, although there is the possibility that it could be either Long-tailed Macaque or Rhesus X Long-tailed Macaque hybrid. The short-tailed species is most likely Stump-tailed Macaque (M. arctoides) as the described taxon appears to inhabit higher elevations and is associated with forests.
As part of the multi-taxa surveys GWC and WWF-CarBi are conducting in Xe Sap NPA we will implement camera trap surveys this fall. Hopefully these will provide us with images of at least the more terrestrial macaques species and can help refine these identifications (this has been our experience in previous camera trap work in the region).
A minimum of eight ungulate species were recorded from Xe Sap NPA. By far the most abundant of these was Wild Pig (Sus scrofa) with signs (tracks, nests) and dung observed in all survey areas.
Muntjac (Muntiacus spp.) tracks and occasional calls were also detected in all areas though they were scarce. We cannot determine either the number or identify of muntjac species present though the common, widespread Northern Red Muntjac (M. vaginalis) is certainly present. Based on the examination of skulls and a harvested animal, two species in the M. truongsonensis/rooseveltorum complex are also present (or were in the recent past). There was no evidence of Large-antlered Muntjac (M. vuquangensis); however, given the upland habitats in Xe Sap NPA (Hill Evergreen Forest and Wet Evergreen Forest) and the limited survey work in its eastern section it is likely present, although clearly at depressed numbers.
Gaur (Bos gaurus) sign was seen through the Pine Savannah Grasslands in southwestern Xe Sap NPA at elevations over 1,000 m, although many of the signs were old and group sizes apparently small (3-4). The ethnic groups living in the area believe that there is a Spirit Protector of Gaur and the species should not be hunted. This may be acting as an conservation measure for this species, although unnaturally low. Interviews with villagers indicate that this is the only wild cattle species in the area. There are large areas of ideal Gaur habitat (Pine Savannah Grasslands interspersed with Hill Evergreen Forest) in this section of the NPA.
There was one record of Serow (Capricornis milneedwardsii) at 1,350 m in Hill Evergreen Forest near Phou Ma Nai. Sambar (Rusa unicolor) was also recorded from western Xe Sap and a captive animal was seen in a village outside western Xe Sap; it had apparently been captured in the Lang Nam District of Salavan Province.
There was limited evidence of carnivore presence in Xe Sap NPA, indicating a decline since the last surveys in 1999. Otters were seen in the Xe La Nong River in western Xe Sap uplands and spraints and tracks recorded in both eastern and western Xe Sap. Owston’s Civet (Chrotogale owstoni) was also recorded from Ban Bhale near eastern Xe Sap NPA. Bear (Ursus spp.) scratches were observed during all surveys, although they were rare and generally old. Interviews with villagers suggest the presence of two species, Malayan Sun Bear (U. malayanus) and Asiatic Black Bear (U. thibetanus), in the area. Two species of porcupine were also recorded, Asian Brush-tailed Porcupine (Atherurus macrourus) from eastern Xe Sap NPA and Malayan Porcupine (Hystrix brachyura) from the western section. Two species of treeshrew, Northern Treeshrew (Tupaia belangeri) and Northern Slender-tailed Treeshrew (Dendrogale murina) were seen in eastern Xe Sap. Squirrels were scarce throughout the NPA and there was only a single sighting of Black Giant Squirrel (Ratufa bicolor), a commonly harvested species. This suggests high hunting pressure in the region.
Preliminary analysis of bird survey results record a minimum of 197 species, including 25 first records for Xe Sap NPA. The avifauna includes a number of endemic species restricted to the Annamite Range. Black-crowned Barwing (Actinodura sodangorum) and Chestnut-eared Laughingthrush (Garrulax konkakinhensis), both listed by the IUCN as Vulnerable, form part of the Kon Tum Endemic Bird Area (EBA) fauna, a region which includes Xe Sap NPA and areas to the east and south. Black-hooded (G. milleti; Near Threatened) and White-cheeked (G. leucolophus) Laughingthrushes form part of the Da Lat Plateau EBA’s fauna, an area which lies southeast in Vietnam and a small portion of eastern Cambodia. Additional Globally Threatened birds recorded during the survey include: Crested Argus (Rheinardia ocellata; NT) heard calling in eastern Xe Sap NPA; scarce records of Blyth’s Kingfisher (Alcedo hercules; NT); groups of up to 12 Austen’s Brown Hornbill (Anorrhinus austeni; NT); multiple records of Yellow-billed Nuthatch (Sitta solangiae; NT), and a montane population of Short-tailed Scimitar Babbler (Rimator danjoui).
Although Xe Sap NPA contains a number of birds distinctive of the central Annamites, the high montane habitats of western Xe Sap appear somewhat depauperate compared to similar areas in the region. This might be due to lower elevations (there was little habitat above 1,800 m) and habitat differences (a possibly drier climate; absence of the cypress Fokenia hodginsii, a forest component strongly associated with this suite of species). Areas which may contain additional Central Annamite species have not yet been surveyed, in particular peaks in the central and eastern sections where climate and habitat may be more hospitable to this avifauna.
Amphibians and Reptiles
Surveys of western Xe Sap recorded 26 species of amphibians and 31 species of reptiles to date; work on identifications are on-going. Among these was the observation of Impressed Tortoise (Manouria impressa) in the field. This is an unusual observations; there have been less than ten records of this globally threatened (IUCN listed as Vulnerable) species in the wild; most records come from animals captured for the wildlife trade. Xe Sap NPA may hold significant populations of this montane species and possibly other upland reptiles (e.g., Black-breasted Leaf Turtle Geoemyda spengleri).
A total of 382 vouchered herbarium collections were made in western Xe Sap NPA during the February surveys. These will be housed in the Biology Department’s Herbarium at National University of Laos and the recently created National Herbarium of Lao PDR. Identification of these specimens is on-going but some observations (in addition to those included in the habitat descriptions above) can be made.
The mature Pinus dalatensis pines recorded in the Hill Evergreen Forests of western Xe Sap is currently the largest known population of this endemic species and of significant conservation concern. It is also the dominant canopy conifer in northwestern Xe Sap’s Montane Conifer Forests, a formation not previously recorded from the region. Three species of orchid with high market value were also recorded Anoectochilus siamensis, A. setaceus, and Paphiopedilum cf. callosum. All three were rare and occurred in limited habitats. It is possible that the P. cf. callosum represents a new species.
In general, forest habitats above 1,000 m in the NPA remain relatively undisturbed. One open question is that the cypress Fokenia hodginsii was not observed although portions of the NPA provide the necessary elevation and climate for it to be present. It is possible that this species is present in areas in central Xe Sap which have not yet been surveyed. Given its location at the transition between two ecotones, additional botanical work is needed to evaluate the conservation significance of the NPA’s flora.
The primary threat to large vertebrates in both Xe Sap NPA and regionally is hunting. This includes both subsistence hunting and targeted collection of high value species for the wildlife trade. Snare lines and hunting camps were unevenly distributed across the surveyed areas, with higher numbers observed in western Xe Sap compared with eastern Xe Sap. Villagers also reported seeing Vietnamese hunters within the NPA. Overall, however, human use of all surveyed areas appears to be relatively low when viewed in a regional context, and it is possible that hunting pressure may have been higher in previous decades.
Logging, both legal and illegal, is an additional threat to the protected area’s biodiversity. Although at this time logging levels seem low, there is evidence of recent activity in the semi-evergreen forests in the foothills in the Ban A Ho area and in general such activity was more intense along the northern borders of the protected area. Agricultural clearance for both agriculture and Bong Tree plantations is an additional threat to the integrity of the region’s forests. Fires are regularly set during the dry season to clear land for planting and facilitate hunting, especially in the Pine Savannah Grasslands of southwestern Xe Sap. Small scale mining for gold also occurs in the protected area, degrading freshwater habitats. Both logging and mining also indirectly threaten biodiversity by increasing the number of people present in the region and via the development of tracks and roads, increasing access to forested areas.
Finally, hydropower development remains an imminent threat to biodiversity in the region. This includes dams being constructed in Vietnam and in Laos on some of the major rivers which either have headwaters in the NPA (Xe La Nong) or run through it (Xe Sap). It is unclear what the impact of these dams will be but they will certainly disrupt the protected area’s important riverine habitats and will also bring more people into the region, increasing pressure on its biodiversity.
Conservation Actions to Date
Results from this first set of biodiversity surveys are currently being incorporated into the Xe Sap NPA management plan being developed by WWF-CarBi and the Departments of Forestry and Agriculture of Salavan and Xe Kong Provinces. Conservation actions will include: determining the placement of guard stations, monitoring and patrol by mixed teams of rangers and villagers, and the development of community-based forest management plans.
GWC and WWF-CarBi will be continuing our collaborative biodiversity exploration work in Xe Sap NPA this fall with the implementation of camera trapping in western Xe Sap NPA. In the future we hope to follow-up on the above surveys, in particular surveying eastern Xe Sap as well as increasing the number of target taxa (e.g., otter and riverine birds, invertebrates, freshwater fishes).