Robert J. Blohm James D. Nichols James E. Hines Ronald E. Reynolds 1995 <p>Knowledge of the timing, magnitude, and cause of mortality in wildlife populations is imperative for developing management strategies that protect or improve the status of these populations. Age- and sex-specific population parameter estimates provide the most useful information for this purpose. Numerous studies have provided information about survival rates in mallards (<i>Anas platyrhynchos</i>), but little is known about age-related differences in female survival during the breeding period. We examined band-recovery data for female mallards banded in southern portions of Alberta, Saskatchewan, and Manitoba during spring and summer 1981-85. We used band-recovery models to test the hypothesis that yearling females would exhibit higher survival compared with that of older females during spring-summer. There was evidence (<i>P</i> = 0.08) that spring-summer survival rates of yearling females (0.728) were higher than that of older females (0.574). These findings support the hypothesis that age-specific differences in nesting behavior (e.g., later nest initiation and fewer nesting attempts by yearlings) influence losses to predators and are responsible for the difference in spring-summer survival. Management treatments that increase nest success, and consequently reduce the need for prolonged nesting, will increase mallard survival during spring-summer.</p> application/pdf 10.2307/3801945 en Wiley Spring-summer survival rates of yearling versus adult mallard females article