The pattern of moult of juvenile Common Chiffchaffs Phylloscopus collybita wintering in two distant localities of the Iberian Peninsula, Málaga (south) and Barcelona (north) differed. Individuals wintering in the northern locality moulted more contour than flight feathers, and vice versa, while sexes did not differ; individuals moulting more contour feathers arrived later and individuals moulting more flight feathers arrived earlier. Taken together, our results suggest that the pattern of moult of juvenile Common Chiffchaffs may depend on the location to which they migrate, in addition to the geographic origin and the time of breeding.
Pagani-Núñez, E., Fregenal, J., Hernández-Gómez, S., & Domínguez-Santaella, M. (2014). Wintering location and moult patterns of juvenile Common Chiffchaffs Phylloscopus collybita. Bird Study, 61(2), 270-276. https://doi.org/10.1080/00063657.2014.907237