Generally speaking, we focus on three main areas:
Biotic Responses to Global Change
For several years, we have been working with an extraordinary specimen series of migratory species, collected for the past 40-years in Chicago. We find consistent morphological responses to increasing temperatures across a wide range of species. Warmer temperatures are driving size reductions, and at the same time wing length is increasing. We have since integrated timing of migration, finding that species are migrating earlier, but that this advance in migration does not seem to be driving increases in wing length that are occurring at the same time...which is...weird! We are continuing to try to understand what is driving the observed increases in wing length in almost all of these species both by better understanding what determines variation in rates of morphological change and the mechanistic basis for the changes we observe.
Additionally, we are trying to understand how spatial patterns may predict temporal responses to changing temperatures. To do this, we developed a new method "Skelevision" for generating large functional trait datasets from museum skeletal specimens. To-date, we have measured traits on over 15,000 specimens! We are using these data to ask whether wing structure is shaped by temperature, and also to test whether there are intra- and inter-specific trends in body size in birds that are consistent with Bergmann's Rule.
Biodiversity and extinction risk
In addition to understanding global change from the perspective of morphological change, we are trying to link research on biodiversity-ecosystem functioning relationships with extinction risk prediction. We have found that - at a global scale - diversity is negatively associated with extinction risk, suggesting biodiversity is not only a target of conservation, but a means of accomplishing conservation. We have also found that for the birds of the the Solomon Archipelago assemblage vulnerability - an ecosystem property - is positively related to diversity, and that this relationship is contingent on biogeographic history. While some aspects of assembly that may be ecologically important may appear random, they assume a degree of predictability when viewed through a phylogenetic lens. This raises an exciting prospect: if community assembly history impacts ecology in a deterministic way, an historical approach to reconstructing assembly may allow for predictions to be made broadly about contemporary ecology. As a first step toward this, we have developed a framework for disentangling the roles of ecology and evolution in guiding community assembly.
Dispersal, Traits, and Behavior
Much of our work is based on the idea that traits are important determinants of ecologically- and evolutionarily-important processes. In testing this idea, we have found that morphological determinants of dispersal ability impact evolutionary processes (diversification rates) and ecological processes (natal dispersal distance and reliance on routine flight). However, the story is also complex! At very small taxonomic scales - combining detailed behavioral observations of foraging behavior in closely related Solomon Islands songbirds - morphology and behavior become decoupled.