Meeting Abstract

P2.48  Jan. 5  Inner beauty in a monomorphic species: immune quality influences mate-choice in Leach’s storm-petrel (Oceanodroma leucorhoa) ZANGMEISTER, J.L.*; CERCHIARA, J.A.; HAUSSMANN, M.F.; MAUCK, R.A.; Kenyon College; Kenyon College; Kenyon College; Kenyon College Zangmeisterj@kenyon.edu

Sexual selection research has most commonly focused on physical characteristics that act as indicators of individual quality; however, past studies have shown assortative mating in some species to be driven by non-morphological traits. Leach’s storm-petrel (Oceanodroma leucorhoa) is a monomorphic seabird without ornamentation, and the factors influencing mate choice are not well understood. Because morphology does not appear to influence breeding choice in this species, we turned to a physiological aspect, immune function, which affects fitness in terms of both survival and reproductive success. A robust immune system not only allows an organism to successfully fight pathogens and parasites, but also indicates that an individual is able to allocate sufficient energy resources for this purpose. We measured constitutive, innate immunity in O. leucorhoa pairs breeding on Kent Island, New Brunswick, Canada, in 2006, using the bacteria-killing assay. We used feather growth rates as an indicator of sex within pairs since males have been shown to grow induced feathers more slowly than females during the breeding season. We found that bacteria killing ability was positively correlated in breeding pairs (r = 0.392, p = 0.039). Given that the effectiveness of immune response may provide a measure of individual quality, these results suggest assortative mating is driven by innate immune function in this species. We are currently running molecular sexing assays to confirm the sex of each bird in a mating pair. While the underlying mechanism for this selection is unknown, this work suggests that a signaling system may be in place in O. leucorhoa which indicates immune quality to potential mates.