[ES] ExTRAcro.—Durante 1988 y 1989 censamos y obtuvimos el area de distribuciôn de una población invernante de Cernicalos Primillas (Falco naumanni). Adultos de amhos sexos permanecieron en invierno en las cercanias de las colonias donde habian criado con anterioridad. El porcentajc de ayes sedentarias respecto al total de reproductores oscild entre el 6 y el 88%. Todos los jóvenes abandonaron las colonias en invierno, migrando a Africa. Las colonias con invernantcs cstaban localizadas en areas agricolas del valle del Guadalquivir. Esta zona tiene inviernos más templados que el resto del area de cria de la especie, y raramcntc sufre hcladas, lo que debe favorecer la actividad de los inscctos que sirven de alimento a los cernicalos en invierno. Los cernicalos utilizaban dormidcros comunales en las proximidades de las colonias y acudian a éstas al amanecer y al atardecer con el fin de visitar los nidos que utilizarian en la siguiente reproduccidn. Los controles de individuos anillados mostraron que los migrantes regresahan gradualmente a las colonias desde Africa entre febrero y abril, apareciendo primero los adultos y después los jóvencs nacidos en el ann anterior

[EN] During 1988—1989 we studied a wintering population of Lesser Kestrel (Falco naumnanni) in the south of Spain, by mapping the area in which they occurred and estimating their numbers. Adults of both sexes remained during winter in the vicinity of the colony at which they had previously bred. The percentage of sedentary birds to total breeders varied from 6 to 88%. All juveniles left the colonies during winter, migrating to Africa. All colonies with sedentary birds arc located in areas of farmland in the Guadalquivir river valley. This area has milder winters than the rest of the breeding range and almost never experiences frost, presumably favoring the winter activity of insects on which kestrels feed. During winter, Lesser Kestrels used communal roosts close to the colony, where they went regularly at dawn and dusk to visit the nest-holes they would be using during the next breeding season. Individuals equipped with PVC color bands showed that migrants returned to the colony from Africa gradually between February to April. Adults were the first to arrive, followed by juveniles born the previous year

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