Migration patterns of two populations of Twite Carduelis flavirostris in Britain

Following a recent large decline in range and numbers, the Twite Carduelis flavirostris is a red-listed bird of conservation concern. An understanding of the species’ movements between wintering and breeding areas is essential to underpin effective conservation. The migration patterns of two populations of Twite were examined: those breeding in the South Pennines and those wintering on the west coast of Lancashire and Cumbria. This was achieved by carrying out an intensive colour-ringing study on the two populations between 2003 and 2005. Birds breeding in the South Pennines wintered predominantly on the east and southeast coasts of England. However, a small number migrated to the west coast of England. Furthermore, large flocks of predominantly South Pennines-bred individuals overwintered in the South Pennines. From the single previous recovery, northwest-coast birds were also thought to originate from the South Pennines. However, resightings from this study suggest that these birds breed primarily on the west-coast islands of Scotland, with smaller numbers breeding on the Scottish mainland. Some interaction occurred between northwest-coast and South Pennines birds, with several birds ringed on the northwest coast found wintering during the same or subsequent year on the coast of Lincolnshire. Two birds ringed in the South Pennines were found breeding elsewhere in subsequent years: one in Scotland and one in Wales. This study has shown that, despite a small amount of cross-dispersal, these two populations have entirely different wintering and breeding grounds, and should be treated discretely for the purposes of future conservation management plans

Andre F. Raine, David J. Sowter, Andrew F. Brown and William J. Sutherland, Ringing & Migration (2006) 23, 45-52