Modeling temporal and spatial colony‐site dynamics in a long‐lived seabird
We studied the determinants of colony site dynamics in Audouin's gull, Larus audouinii, breeding in a small archipelago of the western Mediterranean. Data on island occupation were available for a series of 25 years, since first colonization of the archipelago in 1973. Group behavior was studied in relation to the components of dispersal: permanence or abandonment (extinction) on an island previously occupied and permanence or occupation (colonization) of another island. Generalized Linear Mixed Models (GLMMs) were used to identify the relative contribution of each explanatory variable to the probability of colony abandonment. Gulls showed a low probability (3%) of abandoning one of the isl…
Herramientas estadísticas para resolver contrastes de hipótesis con contenido biológico: su uso en ecología del siglo XXI
Amenudo la formación que han recibido durante la carrera los jóvenes investigadores tiene notables carencias en los aspectos prácticos de diseño experimental, análisis de datos e interpretación de resultados, lo cual limita de manera decisiva el provecho científico futuro de sus actividades. Eso es especialmente cierto en nuestros días, ya que vivimos una revolución importante en el campo de la metodología estadística e incluso en el procedimiento de hacer inferencia (el salto matemático desde las propiedades de nuestra muestra de datos a las de los parámetros desconocidos de la población, nuestro objeto de estudio), que afecta no sólo a los ecólogos sino a muchas otras disciplinas científi…
Contrasting age-specific recruitment and survival at different spatial scales: A case study with the European storm petrel
Evolutionary studies on optimal decisions or conservation guidelines are often derived by generalising patterns from a single population, while inter-population variability in life-history traits is seldom considered. We investigated here how survival and recruitment probabilities changed with age at different geographical scales using the encounter histories of 5523 European storm petrels from three Mediterranean colonies, and also how our estimates of these parameters might be expected to affect population growth rates using population matrix models. We recorded similar patterns among colonies, but also important biological differences. Local survival, recruitment and breeding success inc…