Date of Surveys
Field surveys were conducted 21 October - 19 November, 2008; camera-trapping surveys continued through 11 February, 2009.
Description of Survey Area
Surveys were conducted in Southwest Cambodia’s lowlands, a complex habitat mosaic lying between the Cardamom Mountains and the Gulf of Thailand. The Cardamoms are Cambodia’s only major upland complex, peaking at ca. 1,800 m, and the rivers draining this range run through a wide variety of habitats, including Melalecua woodlands, riparian semi-evergreen forests, ox bow lakes, blackwater swamps, seasonal and permanent pools and marshes, mangroves and rear-mangroves, and coasts and beaches. Grasslands and deciduous dipterocarp woodlands are also present on higher ground and there are a few relict patches of peat swamp forest.
The southwest’s upland regions are largely protected by the Phnom Samkos and Phnom Aural Wildlife Sanctuaries (WS) and the intervening Cardamom Protection Forest (PF). Its lowlands are less well covered by a patchwork of sometimes disjunct protected areas, including the Peam Krasop WS, Botum-sakor National Park (NP), Dong Peng Multiple Use Area (MUA), and Ream, Bokor, and Kirirom NPs. The newly created Southwest Elephant Corridor PF covers low- mid-elevation areas inland of Peam Krasop NP and Botum-sakor NP. However, there are no protected areas providing contiguous coverage linking upland and lowland regions.
Reasons for the Survey
Our goal was to produce a preliminary assessment of Southwest Cambodia’s biodiversity and current threat levels to guide future research and conservation efforts. Previous regional surveys have largely focused either in upland areas or on focal taxa at localized sites (e.g., Siamese Crocodile Crocodylus siamensis). Here we worked in the relatively little known lowland and coastal strip running from Peam Krasop WS southeast to Dong Peng MUA and Ream and Bokor NPs. Threatened species that might be present at globally significant levels include turtles, crocodiles, otters, Indochinese Hog Deer (Axis porcinus annamiticus), Indochinese Silvered Langur (Trachypithecus germaini), eagles, and large waterbirds. Despite this, the integrity of the area’s habitats had never been assessed previously. Following two aerial surveys, seven sites encompassing all major habitat types were selected for follow-up ground work (including boat surveys and camera-trapping). The team also gathered information on threats via observation and informal interviews with local people.
The surveys found a rich diversity of lowland habitats and a number of species of potential conservation significance. Among these are the Critically Endangered Southern Mangrove Terrapin Batagur affinis (IUCN listed as Critically Endangered), whose most significant global populations are likely restricted to Southwest Cambodia’s lowlands. The team also discovered the presence of the Indochinese Hog Deer (Endangered), including tracks, trophies, and camera trap images. This is only the second known extant population of this subspecies in the world. Surveys confirmed the presence of two globally threatened otter species, the Hairy-nosed (Lutra sumatrana) and Smooth-coated (Lutrogale perspicillata) Otters. Given the difficulty of identifying otters to species using either tracks or camera trap images, it is possible that additional species are also present. The poorly known, Indochinese Silvered Langur (Endangered) was also detected at two sites and a potentially significant community of large waterbirds found throughout the survey region. The absence of some target species (e.g., White-winged Duck Cairina scutulata, Masked Finfoot Heliopais personata) was disappointing but not definitive given survey’s briefness.
Overall, the area’s human population is relatively low although agricultural plots are scattered throughout the landscape. In addition to small-scale agriculture, threats to the region’s biodiversity include settlement expansion, hunting, fishing and other wildlife collecting, development of commercial agriculture, logging of mangroves and select high-value timber species, coastal infrastructure development, and sand mining.
Because these are preliminary surveys focused on species and habitats of potential conservation significance, we did not conduct thorough inventories. The team did record a total of twenty-two species considered globally Threatened and Near Threatened by the IUCN Red List:
Southern Mangrove Terrapin Batagur affinis
Indochinese Silvered Langur Trachypithecus germaini
Pileated Gibbon Hylobates pileatus
Hairy-nosed Otter Lutra sumatrana
Indochinese Hog Deer Axis porcinus annamiticus
Elongated Tortoise Indotestudo elongata
Asian Arowana Scleropages formosus
Asian Black/Sun Bear Ursus thibetanus/U. malayanus
Smooth-coated Otter Lutrogale perspicillata
Large-spotted Civet Viverra megaspila
Irrawaddy Dolphin Orcaella brevirostris
Sambar Cervus unicolor
Green Peafowl Pavo muticus
Milky Stork Mycteria cinerea
Lesser Adjutant Leptoptilos javanicus
Black Giant Squirrel Ratufa bicolor
Great Hornbill Buceros bicornis
Lesser Fish Eagle Ichthyophaga humilis
Grey-headed Fish Eagle Ichthyophaga ichthyaetus
Painted Stork Mycteria leucocephala
Black-necked Stork Ephippiorhynchus asiaticus
Asian Box Turtle Cyclemys atripons
Southwest Cambodia’s lowlands harbor significant biodiversity, including globally important populations of Southern Mangrove Terrapin and Indochinese Hog Deer. Terrapins are dependent on exposed sand formations along banks and in rivers for nesting sites and conservation of these areas coupled with reduced hunting is critical to their survival. Hog deer will also require protection. Fauna and Flora International has recently (2013) confirmed the continued presence of Hog Deer in the region and is working with the Forestry Administration and other organizations on law enforcement and additional conservation actions. The region also hosts at least two of Mainland Southeast Asia’s four otter species, presenting an opportunity to efficiently conserve a threatened community. The conservation of all of these groups and other threatened species depends on protecting riparian, estuarine, and grassland habitats. Although human activity and threat levels appear relatively low at present, they are sure to increase in the future. Coastal infrastructure development, and hunting will remain a constant threat as the region’s population grows and demand from the international wildlife trade persists.