Insights on dispersal and recruitment paradigms: sex- and age-dependent variations in a nomadic breeder.

摘要: Sex- and age-dependence in recruitment dispersal are often explained by costs arising from competition for holding a breeding territory over the years—a typical feature of species living stable habitats. For instance, long-lived birds with male territoriality exhibit large variation age higher females young individuals. As corollary, we expected that ephemeral habitat suitability, hence nomadic breeding, would show weak age- sex-dependence low age, because ownership is not maintained years. In addition, cost reproduction might be (over)compensated males. Accordingly, recruit later than We explored these variations using multievent capture–recapture models 13 years, 3479 (2392 sexed) slender-billed gulls (Chroicocephalus genei) 45 colony sites along French Mediterranean coast. expected, variability was males recruiting earlier females. Nonetheless, out study area decreased slightly Decreased result foraging benefits associated increased spatial familiarity. Higher male-biased sex ratio or philopatry (arising their reproduction). age-dependent may thus occur absence year-to-year ownership, which stresses importance considering other processes shaping patterns.