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Study and conservation of Varanids of Thailand

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Varanids are lizards of the Varanus genus, the largest lizards of Thailand.  In Thailand, there are four taxa of Varanids: Varanus bengalensis nebulosus, Varanus dumerilii, Varanus rudicollis and Varanus salvator macromaculatus.  A fifth species of monitor was documented in Thailand, Varanus flavescens (Boulenger, 1912) in Trang; however, this account and others in peninsular Malaysia appear to have been Varanus bengalensis nebulosus.

 Little study has been done of Thailand?s Varanids. The protection given by the Wildlife Reservation and Protection Act BE 2535 (1992) which has helped in the conservation of the genus Varanus has also greatly hindered their study. On top of the protection law hindering research, regulations concerning the use of radio frequencies and the accompanying bureaucracy that accompanies the regulations greatly hinder the use of radio transmitters which are needed for a comprehensive study of Varanid ecology.  Over the two decades since this protection has been afforded, only Lauprasert & Thirakupt (2001) represents a published large scale monitor specific study.  Nutphand (1991) gave a good account of all the monitor lizards of Thailand to include the description of Varanus salvator komaini, which was recently made a junior synonym of Varanus salvator macromaculatus by Koch et al. (2007).  Other publications written on Thai Varanids (Cota et al., 2008; Bundhitwongrut et al., 2008; Duengkae, 2008; Duengkae & Chuaynkern, 2009) have relied primarily on information from herpetofaunal surveys or observation.


Without a question, the Thai law, the Wildlife Reservation and Protection Act BE 2535 (1992), protecting all Varanus spp. has had an overall positive impact on the survival of Thai Varanus spp., along with the view of Varanus salvator being a dirty animal, thus not being targeted for exploitation as food.  The law protecting monitor lizards in Thailand not only keeps wild populations from being exploited by the leather trade, which is by far the greatest exploitation of monitor lizards world-wide (UNEP-WCMC CITES Trade Database), they also protect the monitor lizards from being exploited in the ever growing EU, US, Japanese and Chinese pet trades.  


Although there is legal protection which keeps exploitation from occurring on a large scale, a future challenge in the conservation of Varanids is smaller scale exploitation that is occurring from smuggling of Thai monitor lizards for the pet trade.  Some of these monitors are smuggled directly, while others are ?laundered? through another country for export.  Since CITES is only concerned with species and not subspecies or variants, there is no official way to stop this illegal trafficking; however, some countries will take the steps to stop this, when reported and can be verified.  This exploitation has been particularly damaging to melanistic race of Varanus salvator macromaculatus from Southern Thailand, which is not commonly found, but has appeared in the pet trade in Japan and the United States (Cota pers. obs.)

Another future challenge in the conservation of Varanids in Thailand is the exploitation of Varanus bengalensis nebulosus as food.  This exploitation, particularly in Northern and Northeastern Thailand, has wiped out this taxon from large areas of these regions and healthy populations occur only in protected areas, such as national parks (Cota unpl. obs.). Even though there is a law protecting them, they are commonly sold openly in food markets (Cota pers. obs). Nothing appears to have been done to inform the public that this species carries a deadly parasite (Kampittaya et al., 2000), which should further discourage local exploitation as a food source.

As with so many species of animals, habitat destruction poses a great challenge to the conservation of Thai Varanids, particularly species that rely greatly on pristine habitat for their survival, such as Varanus dumerilii and Varanus rudicollis.  While Varanus bengalensis nebulosus thrive in pristine habitat, they can survive in areas that are disturbed, as long as they are not overly exploited as a food source.  Varanus salvator macromaculatus is among the most adaptable of all Varanus spp., as long as they have access to water; however, with habitat destruction we will see the disappearance of Varanus dumerilii and Varanus rudicollis.  Thailand?s setting aside 15% of the country as national parks and aggressive reforestation efforts gives the future conservation of all Thailand?s Varanids a positive outlook for the future.


Michael Cota
Thailand Natural History Museum, National Science Museum, Thailand