Sex interacts with fledge date to influence dispersal probability in <i>Fratercula arctica</i> (Atlantic Puffin)

Abstract Dispersal is a fundamental life-history component of species, affecting ecological and evolutionary processes. Sex-specific patterns of dispersal may arise to alleviate the effects of inbreeding, kin competition, or limited resources, and are common in many taxa. We examined sex-biased dispersal of Fratercula arctica (Atlantic Puffin) hatched on Machias Seal Island to 4 breeding colonies in the Gulf of Maine using mark–recapture data. We evaluated if one sex disperses more frequently, if there is a sex bias in the breeding colony choice of dispersed F. arctica, and if sex interacts with other individual factors to influence dispersal. There was no significant difference in the frequency that female and male F. arctica dispersed, or the breeding colony they dispersed to. However, we found that with increasing fledge date, female F. arctica were more likely to disperse and males were less likely to disperse, with this relationship being weaker for male F. arctica. Fledge date was unrelated to body condition, and so other rearing conditions or broader environmental constraints reflected by fledge date may be more influential for females when making dispersal decisions. Our results suggest the smaller Gulf of Maine colonies receive a balanced sex ratio of immigrants from Machias Seal Island, which improves our understanding of metapopulation dynamics. The frequency of dispersal differed among years, and was not fully explained by sex or fledge date, highlighting the need for further research to understand which factors influence F. arctica dispersal.