Simple SummaryThe illegal wildlife trade is a significant threat to biodiversity, with animals being taken from the wild and sold illegally. Often, species with the greatest demand are those that are already threatened, with illegal trade placing even more pressure on these populations. Knowing where traded animals or animal parts have come from is critically important for enforcement, education, and conservation actions. Using three highly traded Philippine species, the Palawan forest turtle, the Philippine cockatoo, and the Philippine pangolin, we developed a novel method of determining the geographic origin of animals or animal parts using a portable X-ray fluorescence device. This method can make significant contributions to combating the illegal wildlife trade through providing a rapid, non-destructive, cost-effective method for identifying the source of traded animals. End users of this tool include enforcement agencies, border force officials, wildlife rescue centres, and conservation researchers.AbstractThe illegal wildlife trade is a significant threat to global biodiversity, often targeting already threatened species. In combating the trade, it is critical to know the provenance of the traded animal or part to facilitate targeted conservation actions, such as education and enforcement. Here, we present and compare two methods, portable X-ray fluorescence (pXRF) and stable isotope analysis (SIA), to determine both the geographic and source provenance (captive or wild) of traded animals and their parts. Using three critically endangered, frequently illegally traded Philippine species, the Palawan forest turtle (Siebenrockiella leytensis), the Philippine cockatoo (Cacatua haematuropygia), and the Philippine pangolin (Manis culionensisis), we demonstrate that using these methods, we can more accurately assign provenance using pXRF data (x¯= 83%) than SIA data (x¯= 47%). Our results indicate that these methods provide a valuable forensic tool that can be used in combating the illegal wildlife trade.