As a tropical ecologist I am concerned with two great realities of the 20th century: the catastrophic destruction of biodiversity, and the dissolution of first-hand human knowledge about organisms and the habitats where they occur. It is my belief that a broad-based understanding of whole organisms, terrestrial habitats, and the conservation of biodiversity is important to the biological sciences in particular, and the world at large. My research has centered primarily on the diversity, ecology, behavior and evolution of tropical butterflies, with particular emphasis on two groups: the Riodinidae and Nymphalidae. More broadly, the questions motivating my interests concern the interplay among different organisms and habitats, and what factors contribute to the organization, diversification, and evolution of tropical biodiversity. There are several types of questions that especially intrigue me. Under what circumstances do symbiotic associations occur, and what factors are fundamental to the evolution and maintenance of these associations? What factors contribute to the difference in biodiversity between areas habitats?, and What factors are important to the maintenance and conservation of biodiversity?
My research typically incorporates a vigorous field program with a strong orientation toward comparative, experimental and conservation-based research. To explore general questions, I use and encourage both experimental and comparative techniques on functionally related species of organisms, and view morphological, systematic, behavioral and ecological perspectives as integral components in understanding broad patterns of biological diversification.
Current Research Program
My current research program embraces four main areas. The first centers on understanding patterns of tropical insect community diversity in spatial and temporal dimensions. I employ a standardized sampling protocol in an array of habitats and use powerful analytical techniques to show dynamic habitat effects on species abundance distributions of fruit-feeding butterflies in space and time. One Ecuadorian study is in its ninth consecutive year of monthly monitoring, and represents one of the most detailed, long-term monitoring studies on a diverse insect community ever conducted. By developing a long-term, model system that can recover fundamental patterns of diversity in space and time this work has been directly relevant to understanding tropical community structure and conservation, and it has inspired much theoretical and empirical work by other researchers. Present collaborations include testing theoretical population models and diversity estimation techniques against my long-term data sets. While continuing work in Ecuador, I have begun collaborations in Costa Rica, Brazil, Peru, Suriname and Uganda to conduct similar, comparative studies.
The second research area centers on the widespread symbioses between butterfly caterpillars, ants and plants. My work on riodinid butterflies has focused on understanding their association with ants, how their caterpillars invade and exploit other symbioses with ants, and my research has motivated considerable work by other researchers. I continue to explore this system through ecological and systematic studies on the evolution of caterpillar-ant symbioses, with special emphasis on my original discovery of the acoustical communication systems between caterpillars and ants. Three recent findings include direct fossil evidence that symbioses among riodinid butterflies and ants have been extant for at least 25 million years, showing the evolution of leg-length in caterpillars that are obligate carnivores, and discovery of a new set of semiochemical glands in riodinid caterpillars.
The third research area focuses on interpreting the evolutionary history of butterflies using both morphological and molecular techniques. My colleagues and I conduct phylogenetic research on key groups within the families Riodinidae and Nymphalidae to understand their evolution and diversification. My motivation for this work is that it provides a basis for meaningful ecological and evolutionary comparisons, and stimulates interest in tropical conservation. Recent work includes phylogeny reconstruction and revision in several riodinid genera and the nymphalid subfamilies Morphinae, Amathusiinae and Satyrinae.
Finally, I am writing books for Princeton University Press on butterflies that will span a diversity of topics of interest to a broad audience. The books are field guides that will include color identification plates, illustrations of early stages, range maps, tables and graphs, and summaries of ecology, evolution, conservation biology, and biogeography.
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