Forensic application of DNA barcoding for African pangolin scale traceability

Pangolins are currently recognized as being the most heavily traded group of wild mammals globally. Although various derivatives are found in trade, scales are by far the most frequently seized raw product. This poses a problem for law enforcement personnel as the scales of all eight pangolin species are very similar in appearance, and molecular techniques often need to be employed to verify the species identify of these scales.

This study investigated the applicability of DNA barcoding to identify the species in trade using scales purportedly originating from Africa that were confiscated internationally and sampled in chain of custody. This study successfully identified all scales sampled to species level using the previously generated DNA barcode reference database, and has proven the applicability and reliability of using the DNA barcode reference database to determine the pangolin species in international trade. This finding will assist law enforcement personnel globally in their fight to prosecute participants in the illicit pangolin trade.

This study was a collaboration between the National Zoological Gardens of South Africa and the African Pangolin Working Group. The Hong Kong Customs Authorities kindly supplied the material that was analysed.

Our current knowledge of the distribution of Temminck's Ground Pangolins is based purely on sightings data. However due to their cryptic, predominantly nocturnal nature it is often difficult to confirm the presence or absence of pangolins in a region based solely on sightings. It is also not possible to survey the entire country to accurately determine the distribution of pangolins. For these reasons we investigated the use of Ecological Niche Modelling and GIS software to predict the distribution of pangolins in South Africa. Regions that are predicted by the models to be suitable for pangolins , but for which sighting data are lacking, will be targeted by surveys to try and confirm the presence of pangolins. This study gave us our first robust glimpse into what factors might determine the distribution of pangolins in South Africa, and what part human activities may have played in their current distribution.

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Before this study nothing was known of the genetics of southern African pangolin populations, whether there were genetically-distinct subpopulations and whether there was still gene flow between the various subpopulations. This study undertook to rectify these gaps in our knowledge by sequencing tissue samples that were gathered across the southern African range of pangolins and investigating whether there were any geographic differences. We also sequenced the entire mitochondrial genome of Temminck's Ground Pangolin, allowing subsequent studies to use this genome to design suitable molecular markers and also use the whole genome in varies phylogenetic studies.

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This study identified and developed molecular markers that are being used for subsequent research into the genetic diversity and geographic population structuring of pangolins. This study also investigated the suitability of different tissue types as a source of DNA.

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This comprehensive study focused on the ecology and physiology of Temminck’s Ground Pangolins in an arid environment. No studies of any nature had previously been done on pangolins in arid environments, with all previous research focusing on populations in the moister eastern portions of southern Africa. This project represents the first arid-zone study of the species. Key areas of research included determination of home range size, habitat use, dispersal, diet and core body temperature. This project also reviewed the major causes of mortality in Temminck’s Ground Pangolins and suggested mitigation measures that can be implemented to reduce, or prevent, these mortalities.

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