Impacts of large herbivores in closed-canopy tropical forests

Online seminar followed by Q&A – all welcome

Speaker: John W. Terborgh, James B. Duke Professor of Environmental Science / Co-Director of the Center for Tropical Conservation at Duke University, North Carolina

Large herbivores, such as elephants, rhinos, and hippos, are known as “ecosystem engineers” for their capacity to transform vegetation. Such animals have been amply studied in savanna environments in Africa and South Asia where they can be observed and their activities quantified. But large herbivorous mammals are not restricted to open environments; they also occur in closed-canopy forests where direct observations are precluded, making their impacts difficult to study. A better understanding of the role of megaherbivores in tall forests is of more than academic interest because the ecological roles of such animals is being lost to poaching, logging, land clearing, and other human activities almost everywhere they still persist. Does the loss of large herbivores pose a threat to forest ecosystem diversity and stability? If their impacts are large, their loss could have consequences that cascade through the ecosystem, perhaps to the detriment of a broader slice of biodiversity.

For the last decade, John and his wife, Lisa Davenport, have been evaluating the impacts of elephants and other large herbivores in equatorial forests in Africa (Gabon) and Asia (Malaysia). As is true in savannas, elephants and other large herbivores exert profound effects on the structure and species diversity of these forests, reducing stem counts, altering diversity in some surprising ways, and effectively eliminating whole categories of species, at least on local scales. The effect of large herbivores on plant species diversity is thus strongly negative, but in a curious twist, forests in which such animals have been extirpated experience diversity bounce-back. Is there a conservation message in this? Yes, but it has as much to do with other aspects of herbivore ecology as with their direct effects on plant species diversity. If you come to the talk, you’ll find out why.

John W. Terborgh is a James B. Duke Professor of Environmental Science and is Co-Director of the Center for Tropical Conservation at Duke University. He is a member of the National Academy of Science, and for the past thirty-five years, he has been actively involved in tropical ecology and conservation issues. An authority on avian and mammalian ecology in neotropical forests, Dr. Terborgh has published numerous articles and books on conservation themes. Since 1973 he has operated a field station in Peru’s Manu National Park where he has overseen the research of more than 100 investigators. Dr. Terborgh earlier served on the faculties of the University of Maryland and Princeton University. In June 1992 he was awarded a John D. and Catherine T. MacArthur Fellowship in recognition of his distinguished work in tropical ecology, and in April 1996 he was awarded the National Academy of Science Daniel Giraud Elliot medal for his research, and for his book Diversity and the Tropical Rainforest. He has served on several boards and advisory committees related to conservation, including the Wildlands Project, Cultural Survival, The Nature Conservancy, The World Wildlife Fund and both the Primate and Ecology Specialist Groups of the International Union for the Conservation of Nature.