title: Why birds with deferred sexual maturity are sedentary on islands: a systematic review.
abstract: BACKGROUND
  Island faunas have played central roles in the development of evolutionary biology and ecology. Birds are among the most studied organisms on islands, in part because of their dispersal powers linked to migration. Even so, we lack of information about differences in the movement ecology of island versus mainland populations of birds.
  
  
  RESULTS
  Here we present a new general pattern indicating that large birds with deferred sexual maturity are sedentary on islands, and that they become so even when they are migratory on the mainland. Density-dependent variation in the age at first breeding affects the survivorship of insular populations and this, in turn, affects the movement ecology of large birds. Because density-dependent variation in the age of first breeding is critical to the long-term survival of small isolated populations of long-lived species, migratory forms can successfully colonize islands only if they become sedentary once there. Analyses of the movement ecology of continental and insular populations of 314 species of raptors, 113 species of Ciconiiformes and 136 species of passerines, along with individual-based population simulations confirm this prediction.
  
  
  CONCLUSIONS
  This finding has several consequences for speciation, colonization and survival of small isolated population of species with deferred sexual maturity.
authors.affiliation: Department of Ethology and Biodiversity Conservation, Estación Biológica de Doñana, Consejo Superior de Investigaciones Cientificas (CSIC), Seville, Spain. mferrer@ebd.csic.es
authors.forename: Miguel
authors.initials: M
authors.lastname: Ferrer
authors.forename: Keith
authors.initials: K
authors.lastname: Bildstein
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Penteriani
authors.forename: Eva
authors.initials: E
authors.lastname: Casado
authors.forename: Manuela
authors.initials: M
authors.lastname: de Lucas
mesh_terms: D025041:Animal Migration / Q000502:physiology*; D000818:Animals; D001717:Birds / Q000502:physiology*; D005843:Geography; D016014:Linear Models; D012741:Sexual Maturation / Q000502:physiology*; D013045:Species Specificity