Cambodia is one of Southeast Asia’s most biodiverse nations, situated at a unique geographical crossroads. The country is home to a tremendous variety of fauna, boasting hundreds of species of mammals, birds, reptiles, and freshwater fish. This rich animal life is supported by vast river systems, seasonal wetlands, and dense mountain forests. This natural heritage has allowed species both common and rare to thrive, though many now face increasing pressures.
Defining Cambodia’s Key Habitats
The country’s exceptional biodiversity is linked to three major ecological zones, each supporting specialized animal communities. The Tonle Sap Lake, Southeast Asia’s largest freshwater lake, is the center of this dynamic system, undergoing a dramatic annual transformation. During the monsoon season, the Mekong River’s floodwaters reverse the flow of the Tonle Sap River, causing the lake’s surface area to swell significantly. This “flood pulse” inundates surrounding forests, creating a seasonally flooded swamp forest that acts as an immense nursery for fish and a feeding ground for migratory waterbirds.
The Cardamom Mountains in the southwest form a second, distinct habitat of moist evergreen forests. These mountains remain one of the most species-rich ecoregions and harbor a significant portion of Cambodia’s terrestrial mammal population. The third major zone is the Mekong River basin, a vast freshwater ecoregion characterized by braided channels, sandbars, and riverine forests. The river’s unique hydrological features support a large number of fish species and provide a biological corridor for specialized aquatic life.
Iconic and Endemic Terrestrial Mammals
Cambodia’s forests and grasslands host a number of large terrestrial mammals. The Asian Elephant (Elephas maximus), the largest land animal in Asia, finds refuge in the dense forests of the Cardamom Mountains and the eastern province of Mondulkiri. These fragmented populations rely on remaining forest corridors for movement and foraging. Cambodia also provides a stronghold for several primate species, including the endangered Pileated Gibbon (Hylobates pileatus), which has its largest remaining global population here.
Several species of wild cattle and deer, known as ungulates, are characteristic of the open deciduous forests and savannas. The Banteng (Bos javanicus), a wild ox, is classified as endangered, with significant populations surviving in Cambodia’s Eastern Plains Landscape. The Kouprey (Bos sauveli), Cambodia’s national animal, is listed as critically endangered and is feared to be extinct, with no confirmed sightings since the 1970s. Other threatened ungulates include the Eld’s Deer (Rucervus eldii) and the Gaur (Bos gaurus).
The country’s predator guild includes the Clouded Leopard (Neofelis nebulosa), a secretive, nocturnal cat found in the Cardamom Mountains and the eastern plains. This species is known for its distinctive coat patterns and preference for an arboreal lifestyle. Dholes (Cuon alpinus), or Asian wild dogs, are also present, living in cooperative packs within the forest ecosystems. The Sun Bear (Helarctos malayanus), the smallest bear species globally, is characterized by a distinctive orange-yellow chest patch.
Unique Aquatic and Avian Species
The country’s aquatic systems and wetlands support specialized non-mammalian fauna, particularly in the Mekong and Tonle Sap. The critically endangered Mekong River subpopulation of the Irrawaddy Dolphin (Orcaella brevirostris) is an iconic aquatic species, primarily inhabiting a section of the river near Kratie. These dolphins are known for their rounded heads and lack of a distinct beak. The Siamese Crocodile (Crocodylus siamensis), a freshwater reptile, has been observed in the Srepok River, representing one of the last remaining wild populations.
Cambodia is a haven for large, rare waterbirds, especially around the Tonle Sap Lake’s Prek Toal sanctuary. The Giant Ibis (Thaumatibis gigantea), Cambodia’s national bird, is a critically endangered species and the largest flighted bird in the world. This elusive species primarily inhabits the remote dry forests of northern Cambodia. The Sarus Crane (Grus antigone), the world’s tallest flighted bird, finds one of its largest breeding grounds in the country at reserves like Ang Trapeang Thmor.
Other large waterbirds include the Milky Stork (Mycteria cinerea) and the Spot-billed Pelican (Pelecanus philippensis), found in globally important colonies within the Tonle Sap Biosphere Reserve. The White-shouldered Ibis (Pseudibis davisoni) is another threatened resident, with a significant number of the remaining global population found in the eastern and northern parts of the country. These birds rely heavily on the seasonal flooding and fish abundance provided by the Mekong and Tonle Sap systems.
Conservation Status of Cambodian Wildlife
A significant portion of Cambodia’s unique fauna is facing a high state of vulnerability, with many species listed under the highest threat categories. Habitat destruction, particularly deforestation and the draining of wetlands, is a primary factor driving population declines across all groups. Poaching and illegal wildlife trade also continue to place immense pressure on the country’s rarest species.
The list of critically endangered species includes the Mekong Irrawaddy Dolphin, the Kouprey, the Giant Ibis, and the Siamese Crocodile. Several other iconic species, such as the Asian Elephant, Banteng, and Pileated Gibbon, are classified as endangered. The vulnerability of these species highlights the fragile nature of the country’s biodiversity, which is linked to the health of its forest and aquatic ecosystems.