Serpent's source: Determining the source and geographic origin of traded python skins using isotopic and elemental markers

Novel detection of provenance in the illegal wildlife trade using elemental data

“…Likewise, illegal laundering of crocodile lizards ( Shinisaurus crocodilurus ), listed as endangered on the IUCN Red List, has been implicated in its decline in Vietnam due to unsustainable exploitation 22 . To combat this, much emphasis has been placed on tracking illegal trade networks 23 , 24 and in developing forensic tools to determine the origins of species being traded 22 , 25 . However, stemming the illegal trade is challenged because existing forensic tools are either inaccurate, inaccessible, or too expensive, making it difficult to confidently determine specimen identity, geographic origin, or legal status.…”

“…Genetic techniques, like DNA metabarcoding, are suited to this application and have been used to successfully classify specimens 26 , 27 . A further focus is determining the geographic origins of specimens, particularly for species with large geographic ranges, like pangolin, reptiles, and birds 13 , 25 , 28 . Efforts to forensically test for geographic origin have centred on analysis of stable isotopes 29 , 30 , relying on intrinsic tissue signatures fractionated from diets during assimilation 31 – 33 .…”

“…Some success has been had with reptiles in Vietnam 22 and with fish in China, Australia, Malaysia, and Indonesia 34 . However, both stable isotopes and genetic testing perform best for geographically isolated species with small home ranges or with restricted ecological niches 22 , 25 . Furthermore, both tools are expensive, require considerable sample preparation, and cannot be conducted in situ , limiting accessibility and versatility.…”

Corruption and Wildlife Trafficking: Three Case Studies Involving Asia

“…Advances in research of isotopic and elemental markers may help to address questions related to origin and source. Natusch et al (2017) undertook a study of python skins from Indonesia and Vietnam and were able to identify with 100% accuracy geographic origins based upon a combination of these markers, leading to a clear distinction between skins coming from the wild versus those coming from captive breeding facilities.…”

“…There is opportunity for this to occur at the next stage in the production process-the tanning of reptile skins-which occurs in separate facilities. Restrictions on raw skin exports often necessitate the integration of tanneries with registered exporters (UNODC 2016), as evidenced in Indonesia, where the country's 14 skin exporters also operate tanneries (Natusch et al 2017). The exported processed skins are consequently often later reimported to the country of origin because the skins have been manufactured into a variety of products.…”