Stable isotope analysis: a tool for certifying captive or wild caiman leather origin

Abstract

We must provide tools to discriminate products from captive and wild sources products to improve wildlife use sustainability. Stable isotopes of carbon and nitrogen ratios can be potentially useful for such purpose. In this study, we evaluated δ15N and δ13C in Caiman latirostris skins from captive individuals (from Argentina and Brazil) and wild individuals (from Argentina) and leathers (from tanned skins) from both captive and wild individuals (from Argentina). In addition, we compared the isotopic ratios of caiman claws from both wild and captive caimans from Brazil. The main goal of this study was to evaluate the possible differences on the variability of δ15N and δ13C ratios between skins, leathers, and claws from wild and captive animals. As a result, skins, leathers, and claws from the wild individuals have a larger variability of isotopic ratios than those from captive ones. In addition, tanning does not affect data variability. We can thus distinguish skins and leathers from wild and captive animals. Such pattern might be particularly useful in regions where hunting is banned, and only farmed individuals can be traded.