Research in my lab focuses on understanding the patterns and processes underlying speciation in adaptation in birds. Our work spans the fields of phylogenetics, phylogeography, population genetics, spatial ecology, evolutionary physiology, and behavior. All of this work is integrated within an active museum community. Below are brief overviews of some of our on-going work.

Environmental heterogeneity and hybridization

A main focus of ours has been to explore how environmental heterogeneity influences hybridization dynamics between closely related species. In particular we are often motivated by trying to understand the role of rapidly changing climates in driving the movement of avian hybrid zones. Much of this work has focused on the hybrid zone between Indigo (Passerina cyanea) and Lazuli (Passerina amoena) buntings, but we have also pursued similar lines of research using the hybrid zone between Red-breasted (Sphyrapicus ruber) and Red-naped (Sphyrapicus nuchalis) sapsuckers as a model.

Mechanisms of hybrid breakdown

Indigo and Lazuli buntings differ in the timing of molt and migration. Indigos molt on or near their breeding locations shortly after the breeding season concludes and then migrate south to their non-breeding grounds. By contrast, Lazulis leave their breeding locations shortly after the conclusion of the breeding season and undergo a partial migration, stopping in southern Arizona, southern New Mexico, and northern Mexico. During an extended stopover, they molt. And once they’ve completed molt, they continue their southward journey to their non-breeding range. We are currently exploring how these differences in molt and migration timing are manifested in hybrids.

Male Indigo and male Lazuli buntings sing different songs and also differ somewhat dramatically in plumage. Other on-going work in the lab is investigating the relationships between genetic ancestry, song, and plumage with a particular focus on hybrid individuals. This work tests the hypothesis that since male buntings are capable of changing their songs, genetic ancestry should better predict plumage variation than song variation.

Scott Taylor (University of Colorado), Amber Rice (Lehigh University) and Zac Cheviron (University of Montana) and I have an NSF grant exploring how local adaptation among populations of species may influence the maintenance of reproductive isolation between species, focusing on chicakdees. We suspect that in some cases, hybrid individuals may suffer reductions in whole-organism metabolic performance as a result of mito-nuclear incompatibilities. These disruptions in energy metabolism may then have consequences for hybridization dynamics among avian hybrid zones given geographic variation in the intensity of selection on metabolic performance.

[University of Wyoming]   [Department of Zoology & Physiology]   [UW Museum of Vertebrates]
[UW Biodiversity Institute]   [Program in Ecology]