Darwin's Sexual Selection Theory has had an important impact on the understanding of male-female differences in morphology, physiology, and behavior, as well as in mate selection and competition for access to reproductive resources. Using an avian model (Coturnix japonica) the presenter and colleagues have found that males and females differ in the expression of sexual learning, both Pavlovian and instrumental. They have also explored how early learning affects sexual preference and receptivity in males and females later in life and how learning contributes to improve male reproductive success in sexual competition situations. For example, male quail trained in a Pavlovian learning situation are better able to copulate with females than non-trained males, and male quail who lose in a male-male competition, improve their success after training that allows them to predict the presence of a female partner. Females, on the other hand, improve their proceptive behavior if provided the opportunity to have access to areas occupied by males. The presenter will discuss results of their work, but will argue for a comparative approach to better understand the evolution of the sexual behavior system.