Shane Tobe

While the identification of the species from an unknown sample is a first step, and often a crucial one, it may also be important to identify the region of origin of the sample. This becomes an important issue when a species is protected in one region but not in another, or if wild animals are caught and sold as captive bred. The movement of an animal can also be important in cases such as those of stolen animals or even for conservation purposes. One way to determine the origin of a sample is by comparing the ratios of different isotopes using methods such as inductively coupled plasma mass spectrometry (ICP-MS) and isotope ratio mass spectrometry (IRMS). This chapter will give a very basic understanding of the principles of isotopes, ICP-MS and IRMS and their uses in tracing the movements of species. It has been written for the reader with little to no understanding of isotopes or their use in forensic wildlife crime and who comes from a mainly biological background. In addition, case examples using the techniques will be presented.