Grants and Contributions:

Grant or Award spanning more than one fiscal year. (2017-2018 to 2022-2023)

Finding a mate can be costly as it exposes females to predators and takes time away from other tasks. Understanding why mate preferences have evolved in the face of these costs is my primary research goal. Most indirect-fitness benefits hypotheses suggest mating preferences evolve because elaborate traits reflect greater offspring survival or reproductive success (good genes).

Project 1 lays the founda tion required to test the theory that secondary sexual traits are linked to condition by assessing how nutrition influences the physiological and cognitive foundations associated with performance trait variation. Differences in physiological capacity resulting from energy store disparities, muscle metabolic capacity, or metabolic rate may underlie variation in condition, so I will quantify how nutrition impacts physiological and metabolic performance and the corresponding impact on elaborate traits and preferences. Alternatively, variation in condition may result from differences in how individuals collect, retain and use information, so I will quantify how nutrition impacts cognitive performance and the corresponding impact on elaborate traits and preferences. Together, these experiments will answer “What is condition?”

Projects 2 & 3 directly test the viability-based indicator theory by determining whether sexually selected traits reflect survival under stress and whether females that mate with very attractive males produce offspring with higher viability or reproductive values. Because viability-based indicator models assume high quality males suffer less than low quality males from the costs of trait elaboration, stressors should impact survival of high quality males less than low quality males. I will add stressors unrelated to elaborate traits and quantify whether trait elaboration influences survival (Project 2). I will also test the prediction that females receive indirect-fitness benefits from mating with preferred mates (Project 3). Using a repetitive mating tournament, I will rank-order males based on how strongly females prefer them, and then mate females to the most and least preferred males. I will test whether most and least preferred males differ in their elaborate traits, and whether the offspring of most preferred males have higher viability, produce more elaborate traits, have stronger preferences, have higher fecundity, and have higher survival than the offspring of least preferred males. Project 3 will also enable me to partition out the variance due to genes and environment and test whether environmentally induced variation in condition can be transmitted from father to offspring.

By integrating approaches from behaviour, ecology, physiology, psychology, evolution and genetics, my research program will help biologists understand the evolution of mating preferences and how variation is maintained in traits that confer fitness.