Research Summary:
Richard H. Madden, Research Associate (Ph.D. 1990 Duke University), has research interests in the natural history, ecology, paleontology, ecological morphology and quantitative paleoecology of South American mammals. My current research involves the analysis of ecological data about living mammals and its application to the fossil record of biotic change associated with Andean mountain uplift in the Neogene and climate change in Patagonia during the Eocene-Oligocene transition.
While an undergraduate Anthropology-Biology major at the University of Washington (Seattle), I studied for three years at different universities in Colombia, Ecuador and Peru. Before deciding to enter graduate school, I walked over 1000 miles along the Andes through Ecuador and Peru and studied primate ecology in the Colombian Chocó. As a graduate student at Duke, with the support of the World Wildlife Fund and a Fulbright-Hayes Graduate Fellowship, I undertook mammal inventory and censusing work in the remote Reserva Ecológica Cotacachi-Cayapas in northwestern Ecuador in a study of the impact of human hunting on wildlife in this protected area. Since finishing a doctoral thesis on the Miocene fossil Toxodontidae (Notoungulata) of Colombia, Bolivia and Chile, I've taken 32 expeditions conducting research in mammalian paleontology to every country of South America except Paraguay. This work has been sustained through support from the National Geographic Society, the U.S. National Science Foundation and the Duke-UNC Program in Latin American Studies, and in generous collaboration with Prof. Richard Kay.
Seven research expeditions to Colombia between 1986 and 1991 led to the publication in 1996 of "Vertebrate Paleontology in the Neotropics: The Miocene fauna of La Venta, Colombia" by the Smithsonian Institution Press (ISBN 1-56098-418-X). The book is a compilation of 30 contributions from 38 investigators that collaborated in the study of the fossil vertebrates from this unique equatorial tropical lowland site.
Fossil mammal collections made during seven expeditions to the middle Miocene of southern Chile and Argentina between 1987 and 1993 are permitting the first detailed examination of the relationship between south temperate mammals and uplift-induced climate change in the Patagonian Andes. Closer to the equator, five recent expeditions to the late Oligocene-Pliocene sedimentary sequence of the Bolivian Altiplano have yielded important new paleontological documents for the study of uplift in the central Andes. Finally, the fruits of five research expeditions between 1987 and 1994 have yielded a geochronological framework for a sequence of mammal faunas and plant macrofloras from the middle to late Miocene syntectonic sedimentary rocks in the intermountain basins of southern Ecuador. Now, for the first time we have established sequences of faunas from all latitudes along the Andes, and the study of uplift-induced change on the South American biota can be studied at a level of detail never before possible.
Seven expeditions to Patagonia since 1994 have focused on the Eocene-Oligocene transition, a time of important global climate change and dramatic local faunal change. This work is presently concentrated at a single locality, the Gran Barranca south of Lake Colhué-Huapí in central Chubut Province, the most important fossil mammal sequence in all of South America. Each year we undertake multidisciplinary earth science research at the Gran Barranca in an effort to develop an integrated mammal, plant, and sedimentary record at a global standard of geochronological resolution. This research is conducted in collaboration with faculty and students from the Universidad Nacional de La Plata, the Universidad de Buenos Aires, Duke University, and other domestic and Latin American universities.
As a National Science Foundation International Fellow at the Universidad Nacional de La Plata (Argentina) in 1997, I finished compiling a database of the distribution, ecology and eco-morphology of living mammals in South America. The purpose of this research is to study the relationship between mammal species richness both within and between functional groups or guilds along environmental gradients in South America and to develop transfer functions describing the relationship between richness, rainfall and altitude. I am working toward an evaluation of the performance or predictive ability of these functions and to use them in a calibration exercise to derive estimates of rainfall and paleoaltitude for the fossil mammal faunas. When compared with independent estimates of rainfall and paleoaltitude, the mammal-derived estimates should serve as constraints in modelling studies of Cenozoic climate change in South America.
As part of John Damuth's working group in Mammalian Paleoecology at the National Center for Ecological Analysis and Synthesis (NCEAS), I am contributing to a global database of mammalian ecology and morphology and integrating the South American and global mammal datasets along with climate, soil, topography, vegetation and productivity datasets into a Geographic Information System using ArcInfo8 and ArcView in a new state-of-the-art Dell Precision Workstation.
My other interests include the state of the natural sciences and paleontology in South America and the fate of their practitioners in the context of bipolar political turmoil. I am a North Carolina certified Emergency Medical Technician with a special interest in Wilderness Medical Emergencies.