Researchers have identified several rare and new species in previously unexplored caves across Cambodia, including a flying snake and a fluorescent-turquoise pit viper.
The discovery was made during a multi-year biodiversity study that surveyed over 60 limestone caves in western Cambodia’s Battambang province. The project, led by Fauna & Flora Cambodia and the country’s ministry of environment, explored 10 different hills known for their karst formations, which are limestone cliffs filled with hidden caves and ecosystems.
The organization noted that these karst formations have been some of the least-studied globally, often described as “small islands of habitat” isolated from each other over time due to human activity. Many creatures in these areas are trapped, surrounded by inhospitable landscapes created by humans.
From November 2023 to July 2025, teams of experts explored the caves through narrow gaps and tight tunnels, using flashlights to navigate the pitch-black maze. They discovered numerous rare species, including cryptically camouflaged leaf-toed geckos and vividly colored millipedes, likely quite poisonous.
One notable find was a pit viper, still being formally characterized but described as a “spectacular new species” with triangular heads and heat-sensitive pits behind its nostrils for hunting prey. Other reptiles found included the reticulated python, known as the world’s longest snake, and a bright green flying snake native to South and Southeast Asia.
The biodiversity study aimed not only to learn more about these mysterious ecosystems but also to advocate for their conservation. The organization highlighted that karst habitats are among the least protected globally, threatened by quarrying for cement, unmanaged tourism, wildfires, logging, and hunting. Only 1% of these areas are legally safeguarded.
“Every time you destroy one of these hills, species might be at risk of extinction,” said Sothearen Thi, a biodiversity coordinator involved in the study. “Many species may vanish before they can be discovered.”