Traditionally, it is thought that males increase the likelihood of mating and siring offspring (sexual selection) by one of two means. Males may either compete directly for access to females (male-male competition) or they may have traits that serve to entice females to mate with them (female choice). Mating success can also be a function of whether males guard their mates after mating to prevent other males from mating with them or leave their mates to search for additional females. Preliminary evidence on research with the Mallard duck suggests that levels of testosterone (T) can affect a male's mating strategy. High levels of T seem to promote mate guarding, but also the tendency for males to aggressively seek and pursue females for additional matings. The proposed research investigates the variance in male reproductive tactics, especially as they relate to levels of T. Levels of T will be manipulated in captive male Mallards in large outdoor semi-natural enclosures. The various reproductive tactics used by males will be correlated with levels of T. Additionally, this research seeks to identify regions of the brain that may be involved in various male mating tactics. These experiments will be conducted by undergraduate researchers, whose contributions have been integral and absolutely essential to the PI's research. Undergraduate research at the PI's institution (University of Wisconsin at Whitewater) as a whole is increasing steadily, and continued support is important in providing a learning environment that trains future scientists and clinicians in true scientific discovery. Moreover, UWW has a mission to provide opportunity for underrepresented students (ethnic minorities, disabled students, women, first generation college students).
