Factors affecting wing molt chronology of female mallards

Abstract

We manipulated nest success of captive mallards (Anas platyrhynchos) during two breeding seasons to determine the effects of different breeding events on the timing of wing molt initiation in females. We also studied the effect of different social environments during the postbreeding period on female wing molt chronology. Late (renesting) brood hens molted their remiges later than did early brood hens in both years of the study. Unsuccessful nesters showed a late, asynchronous wing molt when they molted solitarily, but an early, synchronous wing molt when they were placed together during the postbreeding period. There was a positive relationship between the last date of incubation and the date of wing molt initiation when birds were placed in a group after the breeding period. Social environment appeared to influence the timing of wing molt, particularly among unsuccessful nesters. We discuss the implications of these results in terms of postbreeding mortality factors and potential fall banding bias.