The breeding chronology of the mottled duck (Anasfulvi[(ula maculosa) was investigated during a 2-year study in southwest Louisiana. Gonadal measurements were recorded from 37 hunter-killed and 158 collected mottled ducks. A correlation analysis revealed that the ratios of combined testis length to body weight and oviduct width to body weight most accurately revealed reproductive status for males and females, respectively. A quadratic model produced the most significant regression of reproductive status on time for both sexes in 1978 and 1979. Mottled ducks remained sexually quiescent until early January when gonadal recrudescence began. Peak breeding condition for females occurred during mid to late April. about 2 weeks after the peak condition of males.
