Roughly 90% of songbirds are “monogamous”, but the categorization of “monogamy” glosses over interesting natural variation in reproductive composition, as most “monogamous” birds are sexually promiscuous and engage in tactics that can lead to offspring outside of the pair-bond. The trade-offs created by conflicting demands such as male parental care and extra-pair pursuits is unique to social monogamy, with striking differences in how males balance extra-pair vs within-pair choices. I propose to investigate the behavioral differences among male white-crowned sparrows (Zonotrichia leucophrys oriantha), a socially monogamous songbird, that might favor or result from alternative mating tactics leading to variation in reproductive composition. I use cutting-edge bioacoustics and geospatial technology to understand the execution of alternative mating tactics by focusing on advertisement effort. By understanding how variation in reproductive composition persists and the importance it has for overall reproductive success of animals, my research offers insights into overlooked subtleties of avian biology that allow us to further understand the evolution and biological implications of social monogamy.