Assistant Professor; Assistant Curator
About
Fields of Study: Ornithology, speciation, genomics, biogeography, seasonal migration, movement ecology
Research Interests
I am an evolutionary ecologist and ornithologist working at the interface of speciation, biogeography, and behavioral ecology. I develop new analytical tools and employ comparative approaches to leverage large datasets — including those generated from genomics, phylogenetics, museum collections and citizen science — to address longstanding questions in evolution and ecology. My recent fieldwork has focused on the Andes of Peru and Ecuador and the boreal forests of North America.
Some of my recent and ongoing projects include:
Comparative genomics of speciation and community assembly in Andean birds
I am particularly interested in furthering our understanding of mutation-order speciation (speciation that is not caused by divergent ecological selection pressures) and determining how important it is for avian diversification. Cloud forest birds of the Andes —with their incredible diversity of color patterns — will continue to serve as a model system for my speciation research. My research questions include: How much genomic and phenotypic divergence is required for sister species in secondary contact to coexist without exchanging genes? Conversely, how much gene flow between incipient species will prevent their phenotypic differentiation, and how is this gene flow related to dispersal ecology? How does the degree of ecological difference between populations contribute to the tempo of genetic and phenotypic divergence, and their likelihood of achieving sympatry? This research involves comparative genomes, fieldwork in the Andes, and studies of museum specimens.
Geographic range evolution in migratory birds
The seasonal migrations of birds and other animals have long captured human imagination, but our understanding of why species migrate to particular places remains poor. For example, many closely related species of songbirds breed alongside one another in the boreal forests of North America. Yet each fall these species migrate to distinct, often non-overlapping winter ranges — some species to the rainforest of the Amazon, others to Caribbean islands, others no further south than the southern United States — only to return each spring to the same patch of coniferous forest. Why do closely related species with overlapping ranges in one season have such different ranges in other seasons? And if an individual songbird can exist in such diverse habitats as spruce-fir forest and Amazonian jungle, why is its distribution limited to only these disparate biomes? These idiosyncratic distributions challenge our understanding of the factors that limit species’ geographic ranges, and complicate our ability to predict how species will adapt to climate change and environmental degradation. Research on these topics will involve applying phylogenetic comparative to large distributional datasets.
The relationship between seasonal migration and dispersal and its influence on speciation.
Migratory birds move rapidly across large areas of the earth, suggesting that they have high capacity for dispersal throughout their ranges. Yet, many lineages of migratory birds are known to have diversified rapidly, suggesting that the high vagility of migrants does not prevent speciation. Such rapid diversification despite an elevated potential for gene exchange presents an evolutionary paradox that has received little attention. I am studying how migration and dispersal are related, and how these movements influence speciation, in migratory songbirds that breed across the boreal forests of North America. This project involves comparative population genetics to estimate gene flow, and eventually, studying dispersal directly through the use of tracking devices.
Museum science and ornithological inventories
In addition to gathering data for my research on speciation, fieldwork in my lab contributes to our understanding of avian diversity, biogeography, natural history, and conservation priorities in remote and under-studied regions of the tropics, and increases the capacity of museum collections to advance science and conservation.