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New gecko discoveries hint at hidden depths of wildlife haven in Cambodia

Several gecko species found during a series of surveys in a remote region of Cambodia have been confirmed as new to science. And these new discoveries may not be the last in this potentially rich wildlife haven. The research is in the journal ZooKeys.

Asia's karst landscapes—where limestone has eroded to form caves, sinkholes, towers and other striking rock formations—harbor a stunning array of weird and wonderful plants and animals. Many of these hidden gems, from monkeys to minuscule mollusks, have only recently been unearthed. The previously unexplored karst landscapes in western Cambodia's Battambang Province are the latest location whose buried biological treasures have been brought to light.

Four populations of the striped Kamping Poi bent-toed gecko were found and identified as a new species: Cyrtodactylus kampingpoiensis. While they have been described as just one species, the geographic isolation of the karst formations they inhabit probably means that these four populations are on separate evolutionary trajectories, and further genetic analyses may reveal whether they are in fact four different species instead of one.

How isolation drives the evolution of new species

When several individuals of one species become geographically disconnected from other individuals of the same species, the isolated population adapts and evolves independently. Eventually, it becomes sufficiently distinct and genetically separate to be considered a different species; or is deemed a new species based on a range of factors, including isolation, anatomy and genetics. Scientists call this process allopatric speciation.

Because the newly discovered populations are separated by many kilometers of uninhabitable terrain, migration between the karst formations is extremely unlikely. However, until the absence of gene flow between the populations is confirmed, all four groups are being treated as a single, geographically variable species.

Allopatric speciation is common in karst landscapes because of the geographic barriers between karst formations, caused by erosion, changing water courses and development of land for agriculture. It's one of the reasons why these landscapes are home to a wide range of species and a factor that contributes to the fragility of karst ecosystems—the destruction of a single formation can wipe out an entire species.

More geckos await discovery

Another species discovered during the survey, the Battambang leaf-toed gecko Dixonius noctivagus (meaning "night wanderer") is covered in tiny leopard-like spots. Only two species of the Dixonius gecko genus have been identified in Cambodia, far fewer than in neighboring Thailand and Vietnam, which suggests that additional undiscovered species may well exist in the landscape.

A third gecko found during the same survey has also been confirmed as a new species—Hemiphyllodactylus khpoh—already described in the Zootaxa journal.

Given the distribution of these newly discovered geckos, and their distinct genetic lineages, they are likely to meet the criteria for Critically Endangered status on the IUCN Red List of Threatened Species.