I study the evolutionary ecology and mechanistic underpinnings of behavior, with a special focus on same-sex aggressive behavior in birds. While the evolutionary significance and neuroendocrine mechanisms of aggression have been well studied in males, the processes promoting this behavior in females are poorly understood. In my dissertation work, I quantified the fitness costs and benefits of intrasexual aggression in female tree swallows (Tachycineta bicolor). As a postdoc, I am continuing to study aggressive behavior, focusing instead on underlying neuroendocrine and genomic mechanisms. Using the dark eyed junco (Junco hyemalis), I am exploring whether behavioral differences among females and between the sexes map onto variation in neural sensitivity to testosterone (e.g. androgen receptor expression). I am also extending this work to a larger evolutionary scale, comparing hormone mediated mechanisms of aggression in phenotypically distinct populations as well. By combining techniques from behavioral ecology, neuroendocrinology, and molecular genetics, I aim to ask fundamental questions about behavior, connect behavior to physiology, and promote a better understanding of both in the process.