Autumn migration of the Common Sandpiper Actitis hypoleucos in the Ebro Delta Natural Park

The Common Sandpiper Actitis hypoleucos is a common autumn migrant in the Ebro Delta in Spain, although it is uncommon in winter. Autumn migration was studied in this locality from 2007 to 2014. There is an earlier migration passage of adults (median date 22 Jul) than juveniles (10 Sep), with 50 days between the age medians. Nine of 10 birds recaptured within the same autumn increased their mass, with a mean increase of 0.66 g/day. There were no statistically significant differences in biometrics between juveniles and adults. In addition, the flight range estimation revealed a potential flight distance of 2,052 km for juveniles and 2,771 km for adults, indicating that the birds can easily reach North Africa before continuing to their main wintering grounds in West Africa. Our results suggest that the Common Sandpiper in the Mediterranean has an age delayed autumn migration (adult passage earlier than juveniles) and, compared with other European stopover areas, a later juvenile passage.