Migración otoñal diferencial en el Correlimos Zarapitín (Calidris ferruginea) en el delta del Ebro, nordeste de España

Resumen

[eng ] Diffential autumn migration of Curlew Sandpiper (Calidris ferruginea) through the Ebro Delta, Northeast Spain. The sexual differences in the timing of autumn migration in the Curlew Sandpiper (Calidris ferruginea) have never been accurately studied. We surveyed the autumn migration of this species in the Ebro Delta (Northeast Spain) in the autumns of 1992 and 1993. Numbers present in the study were assessed by means of visual counts. The proportion of young and adult males and females was determined from the composition of the samples trapped for ringing. Migration phenology was different in both years. In 1992 few young birds were detected, probably due to the low breeding success in 1992. In the Ebro Delta, adult males migrate ahead of females and peak 10 days before adult females. The early departure of adult males from the breeding grounds seems to be the cause of differential autumn migration in the Curlew Sandpiper.