Rapid microevolution of migratory behaviour in a wild bird species

摘要: THE Blackcap, Sylvia atricapilla, a widespread Palearctic migratory bird, rarely wintered in Britain until the 1950s. The winter population has since increased to several thousand birds1,2. Ringing indicates that these are not British Blackcaps forestalling migration, but birds breeding Continental Europe reaching on novel westerly migration route3,4. proportion of north-western migrants among ringed parts Germany and Austria from 0% before 1960 currently 7–10%5–7. We bred wintering captivity determined direction their offspring. Here we report migrate west-northwest autumn, genetically distinct predominantly southwestern west–central Europe. route must have evolved within past 30 years with selection favouring some 1,500 km further north than most conspecifics. To our knowledge, this is first case any vertebrate which drastic recent evolutionary change behaviour been documented its genetic basis established.