Meeting Abstract

P1.45  Wednesday, Jan. 4  Does physiology mediate the link between acoustic and visual signals and reproductive success in an Arctic passerine? BALDO, S.; GUINDRE-PARKER, S.*; GILCHRIST, H.G; DOUCET, S.M.; MENNILL, D.J.; LOVE, O.L.; Department of Biological Sciences, University of Windsor; Department of Biological Sciences, University of Windsor; National Wildlife Research Centre, Environment Canada; Department of Biological Sciences, University of Windsor; Department of Biological Sciences, University of Windsor; Department of Biological Sciences, University of Windsor guindre@uwindsor.ca

Sexual ornaments are often used to signal quality and through sexual selection can cause intra-specific variation in reproductive success. While this relationship has been established in many taxa, the role of physiology in driving this relationship is less often studied. This could be due to the need for an integrative approach, and/or because most organisms have more than one ornament that can act to signal individual quality, adding complexity to this topic. We acknowledge that organisms have more than one potential signal of quality and use an integrative approach to examine how these signals drive reproductive success in free-living Snow Buntings. Males of this Arctic passerine have two potential sexual ornaments: song and plumage. We study how testosterone, oxidative stress and immunoglobulins may link male song or plumage quality to reproductive success by undertaking the following: 1-Assessing song quality by measuring performance- and complexity-related characteristics. 2-Quantifying plumage traits using feather reflectance, growth rate and pattern of colouration on wing and tail 3-Measuring plasma testosterone and stress-mediated traits 4-Determining the reproductive success of each male. Selected results will be presented on (1) song, plumage and reproductive success, (2) physiological mechanisms that link signals and reproduction, and (3) trade-offs in breeding effort and immune function.