Scratch marks on trees like this one indicate the presence of large mammals like bears in the ecosystem.
Mammals play a key role within an ecosystem. Small mammals are important seed dispersers and maintain the population densities of insects and other invertebrates, while they themselves are prey for larger mammals, reptiles, and birds. The large mammals are the top predators on land (for example, tigers, Panthera tigris, and clouded leopards, Neofelis nebulosa) and in the water (Asian small-clawed otters, Aeonyx cinerea).
Study methods are different for large and small animals.
- Opportunistic observations. Sometimes researchers will just get lucky and catch a glimpse of an elusive tiger or wild pig.
- Track and sign surveys. These were conducted to look for signs of bears, such as scratch marks on trees.
- Interviews. Two Virachey National Park rangers and six porters were interviewed about mammals they had seen.
Traps made of aluminum were used to capture insectivores and rodents. The traps were baited with a mix of dried fish or beef, shrimp, and peanut butter and were set in areas that showed signs of small mammal activity.
Likely areas are hollows under trees, rocky areas, or near holes. The traps were set in the afternoon and checked in the morning.
Mist nets were set along the forest edge and across flight-paths to capture bats. They were opened at dusk and kept open until there were no more signs of activity from bats.
Pitfall traps (also used to capture herpetofauna) were checked twice daily, in the early morning and late evening.
There was evidence of an abundant prey base of mammals consisting of wild pigs (Sus scrofa
), Red Muntjac (Muntiacus muntjac
), and Sambar Deer (Cervus unicolor
), and of top predatory mammals such as the Asian Wild Dog. The impacts of hunting and forest loss on the large mammal populations in the mountains appear to be fairly low. Fewer snares or hunting camps were encountered than in other similar areas in Cambodia.
Bear signs were abundant, and indicated the presence of both the Asiatic Black Bear (Ursus thibetanus) and Malayan Sun Bear (Helarctos malayanus). These bear species are highly threatened by hunting for the medicinal trade in gall bladders and the pet trade. Cat tracks, likely those of the leopard cat (Prionailurus bengalensis), were found around most wetland areas. This species is common throughout Cambodia.
The Rapid Assessment Program (RAP) survey recorded six large mammals which are classified by IUCN as globally threatened: the Gaur (Bos gaurus), Yellow-Cheeked Gibbon (Nomascus sabriellae), Stump-tailed Macaque (Macaca arctoides), Dhole (Cuon alpinus), Asiatic Black Bear (Ursus thibetanus), and Malayan Sun Bear (Helarctos malayanus).
Download the full preliminary report: Cambodia Virachey Park 2007 preliminary RAP Report (PDF - 3.63 MB)
Dhole (Cuon alpinus)
IUCN Status: Endangered
The Dhole is classified as Endangered and fewer than 2,500 are thought to remain in the wild. There are fewer Dhole in the wild than tigers. Rangers stated that this species is widespread throughout the park and the team observed a pack of approximately 10 Dhole, highlighting the crucial importance of Virachey National Park for the conservation of this rare dog.
Malayan Sun Bear (Helarctos malayanus) and Asiatic Black Bear (Ursus thibetanus)
IUCN Status: Vulnerable
The team observed many signs of Malayan Sun Bears and Asiatic Black Bears – both are highly trade-threatened species that have recently been ranked as Vulnerable on the IUCN Red List due to high hunting pressure. Preliminary analyses of transect results indicate that Virachey National Park may have one of the highest densities of bears in Cambodia.
Gaur (Bos gaurus)
IUCN Status: Vulnerable
The team recorded many tracks and signs of wild cattle that were attributed to the Gaur Bos gaurus by the ranger team due to their size and the habitat where they were found. The Gaur is a rare species of wild cattle that is now restricted to mountain pastures in Southeast Asia due to hunting pressure. Many signs-and dung- of Gaur were found in hill evergreen forest.
Yellow-cheeked Gibbon (Nomascus sabriellae)
IUCN Status: Vulnerable
Yellow-cheeked Gibbons call in the early morning. These calls were heard by team-members in evergreen forest at all survey sites. The species appeared to be widespread throughout Virachey National Park, from lowland forest to montane forest. It is provisionally listed by the IUCN Primate SSG as Endangered due to continued and increasing levels of habitat loss and direct persecution. It is also possible that the gibbon species may be Nomascus sika (also provisionally listed as Endangered) as this genus has recently undergone revision.
Stump-tailed Macaque (Macaca arctoides)
IUCN Status: Vulnerable
One adult Stump-tailed Macaque was clearly observed by a team-member in evergreen forest near the Ho Chi Minh road. This species is threatened by habitat loss and collection for the pharmaceutical trade.
Asian Small-clawed Otter (Aeonyx cinerea)
IUCN Status: Near Threatened
There were tracks of otters along the rivers and hill streams of Virachey National Park. In particular, many tracks of otters were found in one area along a large river. Based on their size, we tentatively identified the otters as the Asian Small-clawed Otter, which the IUCN Otter Specialist Group recommended uplisting on the Red List at a recent colloquium in South Korea in 2007. It is threatened due to hunting for the fur trade, so it is a priority species for conservation in Virachey National Park. Small-clawed otters were also stated by Virachey National Park rangers to be found in large pools along the river near the ranger outpost. Two small-clawed otter skins were also observed for sale in Banlung Market after the survey had been completed.
Shrew (Crocidura sp.)
Eleven shrews representing at least two species from the genus Crocidura were caught in pitfall traps in hill evergreen forest. It is likely that they represent new country records and they may even be undescribed species, as the only Crocidura recorded from Cambodia are from the isolated Cardamom Mountains massif in Southwest Cambodia.
This RAP survey clearly shows that Virachey National Park is important for the conservation of many large mammal species. The presence of large packs of Dhole (Cuon alpinus), which require a very large prey base, indicates that the area potentially also provides suitable prey abundance for other large predatory mammals such as the Clouded Leopard (Neofelis nebulosa), IndoChinese Tiger (Panthera tigris), and Asian Golden Cat (Catopuma temminckii).
These cats are mainly threatened by snares, but few snares were observed during the survey and the presence of many other mammals that are also impacted by snares indicates that this threat is minimal at the survey sites. Park rangers state that rare cat species still occur in the National Park.
There are plans to zone the park in the near future, so it is important to incorporate conservation necessities into the management plans for the site that focuses on the most threatened or irreplaceable species, to ensure that suitable habitat areas for these species are included within the core zone.
Focused study should also assess the distribution and status of the Asian Small-clawed Otter (Aeonyx cinerea) in Virachey. This rare otter has not been found anywhere else in Cambodia, so it is important to locate and secure a viable population within a protected area. The otter is an top freshwater predator, so its presence can be used as a coarse indicator of freshwater ecosystem health. It is likely that the rivers of Virachey National Park are globally important for freshwater conservation and should be highlighted as core areas for conservation, so this otter species could serve as a flagship species for conservation of this crucial habitat.
Rangers stated that Douc Langurs (Pygathrix spp.) are present in Virachey, though these were no seen by the team. These primates are extremely rare – the Grey-shanked Douc (Pygathrix cinerea) is on the Global List of the 25 Primates in Peril, and the Red-shanked Douc Langur (Pygathrix nemaeus) is classified as Endangered.
Although relatively few snares were found, it is important that the park rangers maintain high levels of enforcement within the park. There are borders both with Laos and with Vietnam, so the risk of cross-boundary poaching is fairly high. The remoteness of the site and lack of infrastructure currently protects the biodiversity, but this may change as development plans for Ratanakiri Province include road and infrastructure development in and around the national park.