Siamese crocodile

When species are on the brink of extinction, conservation breeding for release can be a vital tool to help with recovery. Genetic analysis can help with planning these breeding programmes, allowing conservation managers to make careful decisions about which animals to breed from.

Siamese crocodiles (Crocodylus siamensis) were once widespread throughout much of mainland Southeast Asia in a range of wetland habitats including slow-moving rivers, lakes, marshes and swamps. The species has now disappeared from 99% of its former range due to hunting and habitat loss.  

Classed as Critically Endangered, it is one of the world’s rarest reptiles, reduced to small, fragmented populations in Cambodia, Indonesia, Laos, Thailand, and Vietnam, with the population size in Cambodia today estimated to be around 250 mature individuals.

In 2012, a Siamese Crocodile conservation breeding facility was established in Cambodia to boost crocodile numbers. The facility produces captive-bred crocodiles for release into the wild. These are complemented with releases of Siamese Crocodiles confiscated from poaching and illegal farming activities or donated by crocodile farms. 

Working with project leads Fauna and Flora International and partners the Royal University of Phnom Penh, RZSS WildGenes is supporting genetic testing for this release programme.  Some Siamese crocodiles in Cambodia have been deliberately cross-bred with other crocodile species. Genetic testing is a vital step to ensure that only suitable animals are used for breeding and release into the wild.