Meeting Abstract
A sexual signal can indicate not only the signaler’s attractiveness as a potential mate but also the signaler’s competitiveness relative to rivals. As the attractiveness or competitiveness of the prevailing signaling environment increases, individuals prospecting for mates should elevate their choice threshold, whereas competing individuals should shift resources toward elevating their own competitiveness. Through a series of experimental manipulations using laboratory-housed Lincoln’s sparrows, we have discovered that females change the strength of their song preferences depending on the attractiveness of the song environment to which they have recently been exposed; compared to a less-attractive environment, a highly-attractive environment elevates the threshold for releasing phonotaxis behavior toward male song. We also discovered that males modulate the competitiveness of their own song behavior based on both the competitiveness of their current, adult environment and the competitiveness of the environment they experienced as juveniles. These behavioral adjustments in females and males are associated with changes in forebrain monoaminergic activity that are triggered by experimental manipulations of the attractiveness and competitiveness of the song environment. Findings from these studies suggest possible neural mechanisms for the regulation of adaptive behavioral plasticity associated with dynamic sexual signaling environments.
