Morphological evolution of some migratory Ficedula flycatchers

Long-distance migration imposes physiological and morphological selection pressures on birds. The genus Ficedula, a lineage of Old World flycatchers, consists of long- and short-distance migratory species, as well as sedentary species. Members of each of these groups are not reciprocally monophyletic, yet each of the behavioral groups is morphologically distinguishable even when accounting for phylogeny. Long-distance migratory species have more pointed wings than either short-distance migratory or sedentary species, and migratory behaviors and wing pointed-ness are phylogenetically correlated. This suggests that migratory Ficedula species have converged on a migratory phenotype, and that migration may be a selective agent that has shaped the independently-derived migratory Ficedula species in similar ways.