Increased extra-pair paternity in broods of aging males and enhanced recruitment of extra-pair young in a migratory bird.

摘要: Despite keen interest in extra-pair mating birds, its adaptive significance remains unresolved. Here, we use a multi-year dataset to test whether traits of female's social mate influence her propensity produce offspring population house wrens, and producing young has consequences for fitness through effects on survival. Females were most likely when paired with old males poor-quality territories, although this latter effect was marginally nonsignificant. Among offspring, the cutaneous immunity within-pair decreased as age their sires increased, but not affected by or rearing them. Extra-pair more than return breeding adults local population, sons being breeder multiple years. Our findings support hypothesis that females enhance inclusive beyond what they are capable given male which socially paired.