While there has been extensive interest in how intraspecific trait variation affects ecological processes, outcomes are highly variable even when individuals are identical: some are lucky while others
Partially migratory populations comprise both resident and migratory individuals. These tactics may coexist if their demographic contribution to future generations (i.e. fitness) are equal or vary tem
Data for the population-level analysis, used to model age-related variation in breeding success for each sex and species (Figure 2; Table S1; Table S2)