Band recovery data were used to examine sex-specific, geographic, and temporal variations in survival and recovery rates of ring-necked ducks (Aythya collaris). Survival rates were higher (P < 0.05) for males than for females in the preseason-banded sample and in 2 of 3 postseason samples; recovery rates were higher (P < 0.05) for females in 1 postseason sample. Survival rates of postseason-banded males were highest in the Mississippi Flyway, whereas rates for females were highest in the Atlantic Flyway. The hypothesis of time-constant survival rates was rejected for all 3 samples of postseason-banded males, and 1 sample of females. The relationships of time-varying survival rates to annual indices of harvest rates and population density were examined. Survival rates of adult males in 1 postseason banding area were negatively correlated with harvest rate (r = -0.78, P < 0.01) and breeding population indices (r = -0.68, P < 0.05). The results are interpreted and discussed in terms of the hypotheses of compensatory and additive mortality, and suggestions are offered for future studies into the relationship between harvest and total mortality.
Additional Publication Details
Variation in survival and recovery rates of ring-necked ducks