Douglass H. Morse Hermon Bumpus Professor Emeritus of Biology, Professor of Ecology and Evolutionary Biology (Research)

I am a behavioral ecologist and study host-parasitoid interactions, foraging behavior and how it relates to life history strategies that affect lifetime fitness, mechanisms of mate choice, and cognitive aspects of innate and learned traits. I review much of this work in three books that span large parts of my research career. I commenced my career at the University of Maryland and came to Brown in 1979 as the Hermon Carey Bumpus Professor of Biology, officially retiring in 2005, but remaining active in my research field, mentoring undergraduate research and offering a reduced number of courses. I chaired the current Department of Ecology and Evolutionary Biology for most of my tenure at Brown.

Brown Affiliations

Research Areas

research overview

My current research focuses on two areas: 1) interactions among the members of a four-trophic-level system involving ferns, caterpillars, primary parasitic wasps and hyperparasitoid wasps (those that parasitize the primary parasitoids!) and 2) the relationship among foraging theory, sexual selection and lifetime fitness. In the latter work I focus on the crab spider Misumena vatia, a sit-and-wait predator that hunts on flowers, but have also worked with birds, bumblebees, and other insects in the past.

research statement

We study a four-trophic-level system involving a crambid moth whose larvae feed on ferns. They exploit two abundant species, sensitive and marsh ferns, and others where available, from at least four families, demonstrating an ability to process a wide range of defensive chemicals. Densities of larvae reach extremely high levels in prime habitat, usually in low-lying areas of old fields. Our main population contains several thousand individuals. The larvae are heavily parasitized by a braconid wasp, which in turn is hyperparasitized by chalcidoid and ichneumonid wasps. This system provides excellent opportuinities for studies of both bottom-up and top-down forces acting among those different trophic levels, including the fourth one.
What effect does the first trophic level, as channeled through the second and third levels, have upon the fourth level? Chemical differences between food plants may affect their quality to herbivores, but what effect may this result play in the success of parasitoids, and on the success of their own parasitoids, the hyperparasitoids? These questions have considerable importance for the success of biological control, yet the parasitoid-hyperparasitoid relationship, a potentially key aspect of parasitoid success, receives considerably less attention than might be expected. Our system permits realistic field experimentation of these links.

We also continue to study the relationship between resource exploitation and lifetime fitness, concentrating on the crab spider Misumena vatia, a sit-and-wait predator that hunts on flowers. The critical activity of adult females is to find food and that of the adult males is to find females. Since the two activities require considerable time and search, they may best be treated as examples of foraging. We have evaluated the consequences of foraging success on key life history variables throughout Misumenaââ'¬â"¢s life cycle. To understand how its attributes and limitations affect it in this quest, we have concentrated on the role of cognitive factors in determining success in foraging at different stages of the life cycle. As one of the most dimorphic of free-living land animals, these studies simultaneously provide insight into the forces driving sexual dimorphism and the degree to which they result from mutualistic and antagonistic selective pressures on the two sexes.

funded research

Research Grants:

National Science Foundation
"Behavioral aspects of competitive interspecific relationships"
$19,100, 1967-1970

National Science Foundation
"The roles of social behavior, resource supply, and vegetation in habitat utilization"
$20,000, 1971-1974, extended to 1975

National Science Foundation
"Foraging ecology: the role of several factors"
$35,000, 1976-1978

National Science Foundation
"Foraging ecology: the role of several factors"
$105,000, 1978-1981

National Science Foundation
"Foraging ecology"
$60,000, 1982-1984

National Science Foundation
"Foraging ecology"
$80,000, 1984-1986

National Science Foundation
"Fitness consequences of variable foraging"
$70,000, 1986-1988

National Science Foundation
"Fitness consequences of variable foraging"
$15,000, 1990-1992

National Science Foundation
"Factors affecting performance in foraging"
$75,000, 1994-1997

National Science Foundation
"Factors affecting performance in foraging" (continuation)
$120,000 (+ supplement of $5000 in 2000), 1999-2003

Biomedical Science, University of Maryland
"The frequency and intensity of agonistic behavior with varying food supplies"
$2,060, 1969-1970

Biomedical Science, University of Maryland
"Population density and agonistic behavior under varying food supplies"
$2,400, 1970-1971

General Research Board, University of Maryland
"Foraging strategies of bumblebees (Bombus)"
$2,500, 1975-1976

Brown University, BRSG
"The role of spatial heterogeneity in host-parasitoid relationships"
$5,426, 1990-1991