Meeting Abstract
Up until the advent of modern molecular techniques, most avian species were considered to be truly monogamous. We now know that social and genetic mating systems are often not the same. Many species that were previously thought to be truly monogamous have been found to have extra-pair young, thus exhibiting evidence for extra-pair reproductive activity. While females face numerous potential fitness benefits from mating with multiple males (e.g. good genes, genetic diversity in offspring), they also face costs (e.g. loss of paternal care, de novo deleterious mutations). Another potential cost of mating with multiple males is acquiring sexually transmitted diseases. In our study, we focused on the sexual transmission of pathogenic microbes, which has been suggested to be a cost of extra-pair activity to females since as early as the 1970s but has not yet been adequately tested. Previous research has identified and described the cloacal microbial communities of birds, however, how sexual activity affects, and is affected by, these communities in wild populations is largely unknown. We took cloacal swabs from adult female tree swallows (Tachycineta bicolor) and then determined the taxonomic composition and pathogenic load of the cloacal microbiome. We also determined paternity of the young as an estimate of the number of males each female had mated with. Through continued observational and future experimental studies, we hope to elucidate the relationship between extra-pair copulations and the presence, prevalence, and pathogenicity of sexually transmitted cloacal microbiota, with respect to fitness, in wild avian populations.
