BIODIVERSITY OF WESTERN SIEM PANG
MAMMALS
This strongly suggests that hunting pressure in this area since 2003 has remained low and the Eld’s Deer population is stable if not even increasing. This is further corroborated by the behaviour of animals; during the May 2011 site visit the majority of animals seen, although cautious, reacted and retreated relatively slowly upon detection, often allowing clear observation for up to a few minutes. This is uncharacteristic of heavily hunted animals, which in general detect human presence before they themselves are detected, and retreat so rapidly that it is generally difficult to determine precisely the species involved. However, the December 2011 survey of areas north of the O Khampha, suggested that there are no longer any Eld’s Deer in this section of Western Siem Pang, which was also corroborated by interviews with local people familiar with the area. Tordoff et al. (2002) and Seng Kim Hout et al. (2003a) both received recent first hand reports of Eld’s Deer from this area, and the latter team found tracks that were likely to have been those of Eld’s Deer. Thus while the heart of Western Siem Pang has experienced a degree of protection most likely due to project activities especially the work of BirdLife and the participation of local community members in other conservation-focused activities, the wildlife in the northern areas has been in significant decline.
Banteng Bos javanicus (Endangered) A once fairly widely distributed species, and locally common in historical times, Banteng is now largely reduced to small isolated populations, most of which are still in decline: the world population may now number fewer than 5,000 animals. Only a single subpopulation of more than 500 animals (estimated), and only 6–8 subpopulations of more than 50 animals, are known, with the single largest subpopulation in the eastern plains of Cambodia and 4–5 on Java and perhaps two in Thailand (Timmins et al. 2008b). In Cambodia, Banteng are estimated to have declined by 90% or more between the late 1960s and the early 1990s. At this latter time they still remained widespread, although in generally low numbers, in the lowland forests of the north and east, and also, probably somewhat more sporadically, in the south and west including the Cardamom Mountain range (Heng Kimchhay et al. 1998; Timmins and Ou Ratanak 2001). From at least this time onwards the most substantial Banteng population has been centred on Mondulkiri Province where in the late 1990s at least several hundred to perhaps over a thousand Banteng survived in a forested landscape of over 15,000 km² (Timmins and Ou Ratanak 2001; Tordoff et al. 2005). Further declines took place from the early 1990s, and as of 2007 the most significant population by far in Cambodia remained that in Mondulkiri Province, still thought to be hundreds of animals (Timmins et al. 2008b). Earlier estimates for Mondulkiri have been recently corroborated by Gray et al. (2011).
Dipterocarp Forest (Duckworth and Hedges 1998, Timmins and Ou Ratanak 2001). This difference in habitat use has a very significant bearing on status; Banteng populations have been much easier to hunt than Gaur simply because of the openness of their preferred habitat, augmented by the preferential clearance of dry forest areas over hill Semi-evergreen Forest (R J Timmins pers. comm.), a pattern common to species characteristic of the dry forest (e.g. Duckworth et al. 2005). There has never been a confirmed record of the species from Western Siem Pang, although it must have occurred. Signs of Banteng or Gaur (the two species are not demonstrably separable with confidence on the basis of footprints), have been sporadically found by BirdLife staff. D. Buckingham photographed oxen tracks near Trapeang Kbal Chkae (UTM 0632612 1581848) in November 2006. Tracks of presumed wild oxen, in areas of predominantly Deciduous Dipterocarp Forest / Nearly-deciduous Forest were seen twice during routine monitoring in 2010, once at Boeung Khdourch (UTM 0621411 1569505) on 4 April, and once at Trapeang Koo (UTM 0630324 1575308) on 18 June (SSG). Also in July 2010 what appeared to be a herd of approximately 14 wild oxen (reported as the Khmer name associated with Gaur) had passed through Deciduous Dipterocarp Forest within Western Siem Pang (SSG). Even in December 2011 tracks of a single oxen (presumed to be either Gaur or Banteng) was found in Deciduous Dipterocarp Forest north of the O Khampha (R J Timmins pers. comm.). Also as recently as 2007, a group of 6-7 Banteng was reported (using the Khmer name associated with Banteng) to have been seen by a local ex-hunter, and there are still occasional reports from the remotest parts of Western Siem Pang (SSG). But as species become rarer and even after their extirpation increasingly erroneous reports are likely to occur as a natural consequence of human nature. At the present stage reports from local communities should be given little weight and viewed with extreme caution. Thus field indications since 2003 have been of small numbers mainly single animals, if indeed they were Banteng at all. It is possible that a few animals might remain, although the species is almost certainly ecologically extinct at the site with no possibility of recovery unless by immigration of animals from adjacent areas. But this is very similar to the situation in many comparable areas of Cambodia. Current indications suggest that Banteng subpopulations in adjacent areas of Laos and Cambodia are not faring any better than those in Western Siem Pang. It seeming even more unlikely that any could remain in Xe Pian NPA given the apparently higher hunting pressure there (see gibbon account), while Conservation International (unpublished) working in Veun Sai-Siem Pang Conservation Area on the southwestern border of Virachey NP has failed to detect the species. Western Siem Pang is hence of relatively low priority for the species, although with adequate protection and enforcement the habitat in much of Western Siem Pang is ideal for the species if they could ever be re-introduced.
Gaur Bos gaurus (Vulnerable)
Research in Xe Pian, in adjacent Laos, has shown that Banteng present there in the late 1990’s showed a strong affiliation with drier and more open habitats, especially Deciduous Dipterocarp Forest, despite increased vulnerability to hunting in these areas. Banteng were not found within large expanses of Semi-evergreen Forest (Steinmetz 2004). This is characteristic of Banteng throughout Indochina and contrasts with Gaur which are generally associated with larger expanses of Semi-evergreen Forest, although they also make use of Deciduous
The population of the subspecies Bos gaurus laosiensis that occurs in Myanmar, Laos, Vietnam, Cambodia, Thailand, and West Malaysia (and presumably southern China) has declined precipitously, especially in Indochina and Malaysia, and perhaps also in Myanmar and China (Duckworth and Hedges 1998). The decline is likely to have been well over 70% over the last three generations (generation length is estimated at 8–10 years).
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