Current fellows at the Smithsonian Migratory Bird Center.
My postdoctoral research is part of the Migratory Connectivity Project, an initiative to conduct comprehensive life cycle analyses for wildlife. It is clear that ascertaining the health of migratory populations across large spatial scales requires an understanding of the geographic linkage of populations between stages of the annual cycle. I am using the 90-year band encounter database at the USGS Bird Banding Laboratory to develop models of migratory connectivity for North American bird species. A bird marked and recaptured at locations in its breeding, wintering, and stopover habitats gives us important information about the migratory connectivity of the population as a whole. Understanding the connectivity of populations becomes increasingly important as rapid changes in resource availability, air space, and climate due to unprecedented human activity may be inflating the risks associated with occupying disparate breeding and wintering areas.
My current research focuses on birds' needs to acquire, maintain, and release energy, and how the interplay among the requirements influences their ecology and evolution. In particular, I'm investigating the selection pressures that these potentially conflicting requirements exert on bill morphology. I'm using the song sparrow as a study species, including 2 subspecies: the eastern song sparrow (Melospiza melodia melodia), which inhabits much of the eastern USA and has a smaller bill, and the Atlantic song sparrow (Melospiza melodia atlantica), which lives a short distance away, only in sand dunes along the Atlantic coast, and has a larger bill. My approaches are experimental, observational, and comparative, and employ developmental biology, functional morphology, and population genetics.
My research interests include quantitative ecology, ecological modeling, population ecology, survival analysis, dynamic programming, avian migration, and occupancy modeling.
Relationships between bird populations / communities and anthropogenic disturbances, including invasions by non-native species, vector-borne diseases, and urbanization. Currently, I am developing analytical methods to quantify the magnitude of bird mortality associated with direct anthropogenic threats (collisions with buildings, communication towers, wind turbines, and predation by domestic cats) and to determine whether these threats have substantial effects on bird populations.
My current research focuses on the impacts of dams on nutrient subsidies to freshwater food webs from marine environments. I am utilizing stable-isotopes to track the ecological impacts of these impediments to salmon migration, and thus marine derived nutrients, on both aquatic and terrestrial food webs. I am focusing this research on an aquatic consumer, the American Dipper, as well as a terrestrial riparian consumer, the Warbling Vireo, on the Olympic Peninsula of Washington State. In addition, I am using tree ring analysis to look at the impacts of dams on riparian ecosystems over a longer time scale. This research is taking place in the context of the largest dam removal project in US history on the Elwha River."