In a Campus Population of Northern Mockingbirds (mimus Polyglottos), Male Mating Success Depends on Experience and Timing

. Many birds are known for ornaments and behavior undertaken in the pursuit of finding and keeping a mate, but for many species, the specific factors that contribute to breeding success remain underexplored. In this study, we tracked the reproductive fates of a population of the Northern Mockingbird, Mimus polyglottos, on the Rice University campus in Houston, Texas. We related male mating success, total fecundity, offspring survival, and rates of extra-pair paternity to body size and condition, the timing of key reproductive events, and metrics of song and of territory quality. Our results indicate that heavier and more experienced males were significantly more likely to attract mates. Birds of both sexes that bred earlier in the season produced significantly more total offspring and enjoyed higher offspring survival. Surprisingly, although M. polyglottos is famous for the complexity of its song and for its high territorial aggression, we did not detect a significant effect of any metric of song or territory quality on mating success, although our song samples were short and exclusively collected early in the breeding season and other measurements might have been more successful. We also detected surprisingly few instances of extra-pair paternity or egg-dumping relative to other socially monogamous songbirds and other mockingbird studies. Our results underscore the variations in reproductive strategy that can exist between different bird species or across different environments.