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.