SURVIVAL OF FEMALE CANVASBACKS WINTERING IN COASTAL LOUISIANA

Annual survival probabilities of female canvasbacks (Aythya valisineri a) are lower than those of males, but sources and timing of mortality are poorly understood. To further elucidate causes of reduced annual s urvival in female canvasbacks, we estimated survival rates for radio-t agged females in coastal Louisiana during winters 1988-91. Survival es timates for winters 1988-91 were 0.946 +/- 0.072 (estimate +/- 95% CI) for adults (n = 82) and 0.952 +/- 0.065 for immatures (n = 51). High survival by females wintering in coastal Louisiana suggests that sex- and age-related differences in canvasback survival occur during other periods of the annual cycle or at other wintering or staging sites.