Role of vertebrates in tropical forests and consequences of extinction
Humans have had devastating impacts on the world’s biodiversity through habitat destruction, overexploitation, invasive species and climate change. The loss of animal species from ecosystems (defaunation) has been a consequence of these anthropogenic pressures, but is also a component of global environmental change in its own right. Extinction is often a non-random process, and species that share functional roles in the environment often share sensitivities to anthropogenic pressures. Although we have made great progress understanding the drivers and patterns of species loss from ecosystems, we are just beginning to understand how species extinctions may, in turn, impact ecological communities and ecosystems. We use observation, field experiments, and simulation models to explore the population, community and higher level consequences of losing functional diversity. In particular, our group has focused on the ecological impacts of vertebrates as insectivores, seed-dispersers, and herbivores, and the consequences of their loss for tropical ecosystems. Our recent and current research projects on this topic are carried out in Madagascar, Gabon, Peru, and the Mariana Islands.