Siamese or mountain crocodile

Picture from endangered-species-1.com

By Dr. Jenny Daltry, FFI and Chheang Dany, DFW Cambodian Crocodile Conservation Programme

The Siamese or Mountain crocodile (Crocodylus siamensis) is one of the world's most endangered animals. It is a handsome, freshwater crocodile with a distinctive bony crest at the back of its head. It is reputed to be rather timid and not a 'man-eater'. Siamese crocodiles have originally inhabited all ASEAN member countries except the Philippines. The large (up to 4m) predators kept watercourses clear and helped to maintain healthy freshwater fisheries. By the 1990s, however, this important animal was widely feared to be extinct in the wild. Intensive field surveys failed to find any in most of their former strongholds.

The crocodile's decline began with competition with rice farmers for wetlands, but the deathblow came in the 1950s, with the rise of organised crocodile farming and the international skin trade. These crocodiles produce fine, soft leather and are easy to breed in captivity. To speek up their production, hybridisation with saltwater crocodiles (C. porosus - native to coastal parts of ASEAN) and Cuban crocodiles (C. rhombifer) was conducted. The thousands of 'Siamese' crocodiles in captivity today contain a bewildering array of mongrels, which only genetic testing can distinguish.

Picture from endangered-species-1.com

Today, two wild individuals have been confirmed in Thailand (one was famously discovered by the US-based Wildlife Conservation Society using a camera trap) and up to 10 are known in Laos. The news from Cambodia is more encouraging, with the recent discovery of breeding colonies in the Cardamom Mountains. Scientists from the Cambodian Department of Forestry & Wildlife (DFW) and the UK-based Fauna & Flora International (FFI) have identified 18 sites here to date, containing over 150 wild Siamese crocodiles.

The DFW and the FFI have learned that the crocodiles require deep, slow-moving rivers and swamps between 10 and 600 m. They prey on small animals, especially snakes and fish., and only rarely attack animals as large as a dog or wild boar. Breeding begins during the dry season and the young hatch after 70 to 80 days; the young remain with their mother for at least two years (it is at least a further 10 years before they themselves are mature). The adults construct burrows, but the purpose of these is still unknown.

Decades of hunting have taught Siamese crocodiles to be shy, but in some parts of the Cardamom Mountains, local people regularly bathe and fish among the crocodiles, which they consider sacred. They believe that killing the crocodiles would bring sickness or death on their families.

The Cambodian government has strengthened the protection for the wild crocodiles, notably by gazetting the new 401,313 ha Central Cardamoms Protection Forest.

Reference

ASEAN Biodiversity (2003), Siamese or mountain crocodile (Crocodylus siamensis), 3 (1&2)