Migración postnupcial del mosquitero musical Phylloscopus trochilus en un herbazal de Albacete

Resumen

This study provides information on the phenology, biometry and changes in body weight of Willow Warblers on a stopover in a meadow near Albacete (SE Spain) during postnuptial migration. The study was conducted by sampling twice a week at dusk in August-October 1999. Peak passage was on 5-11 September; adults arrived earlier than juveniles. Young birds were recaptured more often than adults and also gained more weight during their stopovers at the site; nevertheless, these differences were not statistically significant. Both adults and juveniles were heavier and had higher fat scores at the end of the passage period. The mean recorded weights (10.2 g in juveniles and 10.8 g in adults) were heavier than previously reported in the Iberian Peninsula and North Africa, possibly due to the fact that captures made at the end of the day. In conclusion, although the Willow Warbler passes through the Albacete region on migration in notable and previously unknown numbers, the low recapture rate and the good body condition of captured individuals suggest that the study site is not a critical stopover site en route to Africa.