Song as an honest indicator of oxidative damage and anti-oxidant capacity: Exploring the relationships between signal quality, oxidative status, and reproduction in the Snow Bunting (Plectrophenax nivalis)

Sexual selection has led to the evolution of elaborate signals which enhance mate attraction and reproductive success. Often there is marked variation in signal quality between individuals yet little is known about the physiological mechanisms underlying this variation. Bird song is a signal used to attract mates and repel rivals and can vary between individuals in both content and performance. Oxidative stress is a potential mechanism that may affect song content and performance, explaining some of the inter-individual variation in signal quality. I investigated the relationship between song, oxidative status, and reproduction in the Snow Bunting ( Plectrophenax nivalis ) and found support for the Oxidation Handicap Hypothesis. Birds that sang at a higher rate had higher levels of reactive oxygen metabolites, but also had higher anti-oxidant capacities. Therefore, the ability to avoid oxidative stress is reliably indicated via song performance and reactive oxygen species may be the handicap ensuring signal honesty