DNA barcoding & multi-isotopic fingerprinting

Abstract

Over-exploitation through illegal wildlife trade is a major threat to a wide range of endangered mammal species around the world, particularly to the Felidae. Illegal trade in wild cats is often in the form of bones, meat, skulls, claws and skins. In many cases, this material lacks detailed morphological features for specific identification and constitutes a significant problem for law enforcement or border control to classify them as endangered, protected or illegal wildlife trade. Moreover, wild cat parts are often traded across multiple international borders and along numerous trade routes, making poaching hotspots and potential trade routes difficult to identify. Successful wildlife forensic casework is thus challenged by unresolved issues such as species identification from animal parts and derivatives and the tracking of their geographic origin.<br /> The specific aims of this thesis are to test the feasibility of rapid, accurate and cost-effective methods for species identification and geographic provenancing of felid species in wildlife forensic investigations. The present study focuses on a comprehensive analysis of all thirty-eight species from the highly endangered Felidae, by applying independent lines of evidence: (a) DNA barcoding and (b) multi-isotopic fingerprinting. For species identification, DNA barcoding of mitochondrial markers was applied because of its effective use in various types of animal tissues (bone, hair, blood, faeces, teeth, skin). To reconstruct the geographic origin of an organism, stable isotope analysis via Isotope Ratio Mass Spectrometry (IRMS) was used as tool for wildlife forensics.<br /> The results of this thesis demonstrate the species-diagnostic resolution power of DNA barcoding and potential pitfalls in using water isotopic fingerprinting for geographic provenancing of felids in wildlife forensic investigations. In light of evidence presented here, the combination of DNA barcoding and isotope research opens up new avenues of research with relevance and practical applications for wildlife forensics, border control, law enforcement and isotope- and biodiversity research studies.