Systematics, population structure and demography of the African dwarf crocodile (Osteolaemus spp.): A perspective from multiple scales

Wildlife harvest is the most geographically widespread form of resource extraction in equatorial forests. The illegal trade in wildlife is worth billions of dollars annually, with some estimates placing it second only to the global trafficking in illicit drugs. In competition with the commercial harvest, many rural inhabitants of tropical forests subsist on wildlife as a protein and economic resource. Lack of understanding of the biology of the system and the inability to implement management controls are cited as the two main impediments to sustainable-use practices in the tropics. To achieve long-term sustainability of wildlife resources, we seek an integrated understanding of the dynamics regulating resource populations and the dynamics of extractive activities influencing the fate of population trajectories. To pursue these goals, my research focuses on a poorly known reptile in tropical Africa that is widely consumed in rural diets but threatened by commercial hunting.;African dwarf crocodiles (Osteolaemus spp.) remain an important subsistence food resource throughout Central and West Africa, but are now threatened by overharvesting. The ability to address harvest issues and conservation priorities for crocodile populations is limited by a lack of knowledge of their biology, ecology and evolutionary history. My research approaches this problem from multiple perspectives. I first seek to resolve an 80-year-old debate on the taxonomy of the dwarf crocodile across its range, which has impeded our understanding of evolutionary significant units (ESUs) and the magnitude of the threats facing regional populations. Novel methods for monitoring the trade in crocodiles and other bushmeat species are needed to understand the magnitude of wildlife use in the tropics. I employed a molecular method to identify commonly hunted African wildlife species. I then attempt to gain inference on population genetic structure, connectivity and landscape factors influencing individual movements at the local and regional scales. At the population level, I used field surveys and capture-recapture methods to estimate demographic parameters and model population growth, incorporating empirical estimates of harvest rates and size-selection bias to evaluate their impact on long-term viability. I offer recommendations for new conservation management units, new techniques for monitoring the bushmeat trade and suggestions for spatial harvest management.