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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