Personal Information

• B.A. (Biology and English), 1993, Williams College
• M.F.S. (Forest Science), 1998, Yale School of Forestry and Environmental Studies
• Ph.D. (Population Biology), 2004, University of California at Davis
• Curriculum Vitae

Research Interests

Non-lethal predator-prey interactions and community dynamics. I am interested in exploring how non-lethal interactions between predators and their prey affect food webs and alter community dynamics. I became interested in this question after observing herons stalking grassland rodents during my field work, and being struck by the relative rarity of successful rodent kills. Many organisms are capable of altering phenotypic traits (behavior, development, morphology, etc.) to reduce their risk of predation; changes occurring via the 'non-consumptive effect' (NCE) of predators on their prey can nonetheless incur significant demographic and fitness-level costs. I worked with several co-authors on an analysis of published literature in which we found that the magnitude of the effect of NCEs on prey population growth was roughly equal to the direct lethal effect of predators. I am currently funded by the National Center for Ecological Analysis and Synthesis to lead a group of theoreticians, modelers, and field ecologists in answering when, where, and under what conditions NCEs might be important.

Range expansion of invasive herbivores sharing a common host. Another area of current interest involves the interactions occurring between two invasive herbivores and their shared host plant, the Eastern hemlock. The hemlock woolly adelgid, Adelges tsugae, has been implicated in the decline of hemlock throughout the eastern United States. Eastern hemlock is also attacked by the elongate hemlock scale, Fiorinia externa, which has invaded at least 10 states in the northeast. The interactions between the adelgid and scale, and the role of dispersal and cold tolerance in their range expansion, have never been studied; the results are increasingly important as hemlock stands decline in health and the scale expands its range into that of the adelgid. My work addresses both basic and applied ecological questions in this system and aims at understanding the spread of these invasive species. Some of my research in this area involves assessing the intensity and outcome of adelgid-scale competition occurring when both species colonize the same host plant. The results of these experiments are of considerable practical significance, since understanding how these invasive species interact is essential for predicting their individual and joint effects on hemlock health.