Date of Award


Degree Type


Degree Name

Doctor of Philosophy


Ecology and Evolutionary Biology

Major Professor

Elizabeth P. Derryberry

Committee Members

Benjamin M. Fitzpatrick, Todd M. Freeberg, Brian C. O'Meara, Robb Brumfield


Sexual signals and mating behaviors influence whether sympatric species interbreed, and can therefore promote or impede behavioral reproductive isolation between species in secondary contact. Traditionally, research on sexual selection and hybridization has focused on the importance of interspecific mate choice and species discrimination from the perspective of choosy females, and competition from the lens of aggressive and indiscriminate males. I examined two different avian systems to compare the role of male and female competition on hybridization: white-crowned sparrows on the west coast of the US, and sex-role reversed jacanas in Panama. Using genomics and experimental field techniques, I tested morphological, behavioral, and historical factors that influence patterns of gene flow between lineages. I found that contrary to traditional expectations, divergence in male competitive signals can promote reproductive isolation, and female competition can facilitate hybridization.


Portions of this document were previously published in the journals Current Zoology, Molecular Ecology, and Behavioral Ecology and Sociobiology.

Orcid ID

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