Most studies of variation in male reproductive tactics have focused on conspicuous categorical di¡erences in mating behaviour (i.e. variation in mating strategies). However, in the presence of trade-o¡s between investment in competition over matings, parental care and survival, a male's optimal allocation rule might vary according to his physiological condition and social or ecological environment. Thus, there may also be more subtle variation in male reproductive tactics. Here, I show that the reproductive e¡ort (estimated as residual change in condition) of male collared £ycatchers was a¡ected by the size of their forehead patch (a secondary sexual character), age and date of arrival at the breeding grounds. Among early males (i.e. males with a high likelihood of both attracting more than one female and obtaining extra-pair copulations), large-patched males made a relatively large reproductive e¡ort and as a result were in worse condition at the time of feeding o¡spring as compared to small-patched males. Furthermore, among early breeders, young males and males with experimentally increased forehead patch size made a relatively high e¡ort. By contrast, regardless of age and badge size, there were no such patterns observed among late breeders. These results suggest that collared £ycatchers use di¡erent reproductive tactics depending on both internal and external factors, and that the size of a secondary sexual trait may not only indicate variation in individual condition but also predict how resources will be allocated between pre-and post-mating reproductive activities.