To investigate behavioral or morphological traits important as mate choice cues, we measured selection differentials (s) as the covariances between each trait and male mating success, and directional selection gradients (J3) from multiple linear regression of the standardized traits on male mating success. Data from two leks in four consecutive years were included, and the annual data were analyzed separately. The main findings are: (1) the distribution of male mating success proved to be less skewed than those found in many other lekking species, (2) only a few traits yielded significant selection gradients, (3) the importance of age on male mating success changed across years, (4) females may use traits with a high variance as mate choice cues, and (5) individual males achieved similar mating successes between years. Attendance and age were the traits most consistently correlated with male mating success, but no traits showed significant selection gradients in all years. Our results indicate that variable sexual selection pressures existed between years, but the high correlation found between the mating success of individual males in successive seasons also indicates that permanent differences in male traits are important. Key words: lek, mate choice, sexual selection.