We used breeding population, band recovery, and hunter harvest data to examine whether rates of productivity and harvest correlated with annual changes in mallard (Anas platyrhynchos) breeding populations. Percent change in the size of the breeding population correlated positively with an index of production rate and negatively with an index of harvest rate (R2 = 0.37, F = 8.34, P < 0.005). Average harvest rate indices did not differ (W = 126, P < 0.32) between periods of increasing (1961-69) and decreasing (1970-85) populations. Indices to production tended to be lower (W = 143, P < 0.08) during 1970-85 (.hivin.x = 0.064) compared to 1961-69 (.hivin.x = 1.096).
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Changes in mallard breeding populations in relation to production and harvest rates