Deep within the Battambang Province of western Cambodia lie a series of vast cave systems, spectacular rocky outcrops and pinnacles. This habitat is collectively known as karst – and Cambodia’s karst areas remain some of the least explored on Earth.
Karst ecosystems are formed by rocky limestone hills and caverns dissolving over time, resulting in a landscape that’s dotted with unique features such as large cave springs, sinkholes and sinking streams.
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While these habitats are relatively unexplored, they’re believed to be one of most diverse habitats on Earth, with a high number of endemic species.
To find out exactly how biodiverse Cambodia’s karst region is, conservation charity Fauna & Flora (in collaboration with Cambodia’s Ministry of Environment and field experts) led a survey across the vast landscapes in 2025.
“Battambang is composed of isolated karstic hills and caves; each acting as its own laboratory of natural selection and evolution,” explains Lee Grismer, professor of biology at La Sierra University, USA, who supported the survey team.
“Think of it as their own vignette of biodiversity, where nature is performing the same experiment over and over again independently.”
Now, the survey has been published – and the team has uncovered several species in the region that are new to science.
The survey has also confirmed that the karst areas are home to many threatened species, such as the Sunda pangolin, Indochinese silvered langur, long-tailed macaque and green peafowl.
A “treasure trove” of new species
One of the most striking species that the team catalogued was a new species of pit viper (from the Trimeresurus genus) which is currently being described. Its turquoise hue hints at its highly venomous nature. It tracks warm-blooded prey using heat-sensitive pits located behind its nostrils.
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The ornate flying snake – also known as the golden tree snake – was also documented in the survey. Chrysopelea ornata glides from tree to tree in pursuit of prey by flattening its rib cage. It’s mildly venomous, with three subspecies recognised.
Another species discovered was the Battambang leaf-toed gecko (Dixonius noctivagus), which is covered in small leopard-like spots. Only two species of the Dixonius gecko genus have been identified in Cambodia – far less than in bordering Vietnam and Thailand – with the team suggesting that this indicates further undiscovered species exist in the landscape.
Four populations of the striped Kamping Poi bent-toed gecko were discovered and identified as the new species Cyrtodactylus kampingpoiensis. Although they’ve been described as one species, it’s thought that the four populations are on separate evolutionary trajectories due to their geographic isolation.
Further genetic analyses may reveal whether they’re in fact four individual species instead of one.
Two millipede species were collected, with the bright colouring of the Orthomorpha battambangiensis likely indicating that the species is poisonous – or at the very least, unappealing for predators.
The brown tree frog, also known as the Hong Kong whipping frog, was found in the Phnom Prampi cave in the Battambang province. The frog’s common name comes from the way females uses her back legs to whip up a foam before making a nest for her eggs.
“Cambodia’s karst areas are a treasure trove of scientific secrets waiting to be uncovered,” says Sothearen Thi, who is the karst biodiversity coordinator at Fauna & Fauna.
“From undiscovered reptiles and snails to hidden caves – there is still so much we do not know about these unique ecosystems and the diversity of creatures living within them. But, without sustainable management, we may never find out what these areas truly hold.”
Top image: Sothearen Thi (karst biodiversity coordinator for Fauna & Flora) and Phyrom Choun (protected areas specialist for Fauna & Flora) look for species during a herpetology survey in karst habitat in July 2025. Credit: Manita Hem / Fauna & Flora
