Dispersal and migration in Eurasian Spoonbills Platalea leucorodia

Abstract

Sightings of Eurasian Spoonbills marked at the Odiel marshes, SW. Spain, were analysed to determine the extent of philopatry, sites of dispersal and the temporal and spatial patterns of migration in this population. Odiel Spoonbills winter in the Senegal delta (2500 km south of the Odiel). However, several yearlings made long-distance displacements towards the north during their first summer. Most immature Spoonbills (1-2 year old birds) oversummer in the wintering grounds. Adults return to the colony from January onwards, with older birds arriving first. Among the Spoonbills ringed as young (n = 1789) 33% were resighted as adults, 94% of these adults were seen, at least once, within 100 km of the natal colony. A small proportion of adults (2.4% of 596 birds ringed as young and 3.2% of 62 birds ringed as adults) were seen during the reproductive season in other European countries (in The Netherlands, France and Portugal). Some of these birds were observed within the foraging range of foreign Spoonbill colonies or even reported breeding there, indicating a gene flow among W. European populations of Spoonbills.