title: Population characteristics may reduce the levels of individual call identity.
abstract: Individual variability influences the demographic and evolutionary dynamics of spatially structured populations, and conversely ecological and evolutionary dynamics provide the context under which variations at the individual level occur. Therefore, it is essential to identify and characterize the importance of the different factors that may promote or hinder individual variability. Animal signaling is a prime example of a type of behavior that is largely dependent on both the features of individuals and the characteristics of the population to which they belong. After 10 years studying the dynamics of a population of a long-lived species, the eagle owl (Bubo bubo), we investigated the emergence and maintenance of traits that reveal individual identity by focusing on vocal features. We found that individuals inhabiting a high density population characterized by a relative lack of heterogeneity (in terms of prey availability and breeding success) among breeding sites might be selected for reducing the levels of identity. Two non-mutually exclusive hypotheses may explain the structural call patterns we detected: (1) similarity in calls may be principally a consequence of the particular characteristics of the population; and (2) high density may encourage individuals to mimic each other's vocalizations in a cascade effect, leading to a widespread and unique communication network.
authors.affiliation: Metapopulation Research Group, Department of Biosciences, University of Helsinki, Helsinki, Finland ; Department of Conservation Biology, Estación Biológica de Doñana, CSIC, Seville, Spain.
authors.forename: María del Mar
authors.initials: Mdel M
authors.lastname: Delgado
authors.forename: Eleonora
authors.initials: E
authors.lastname: Caferri
authors.forename: Maria
authors.initials: M
authors.lastname: Méndez
authors.forename: José A
authors.initials: JA
authors.lastname: Godoy
authors.forename: Letizia
authors.initials: L
authors.lastname: Campioni
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Penteriani
mesh_terms: D000818:Animals; D004463:Ecology; D007206:Individuality; D011156:Population Density; D011157:Population Dynamics; D020305:Strigiformes / Q000502:physiology*