Editing Common merganser (section)

===Movements===
The species is a partial [[bird migration|migrant]], with birds moving away from areas where rivers and large lakes freeze in the winter, but resident where waters remain open. Birds from Eastern North America migrate south in small groups to the United States wherever lakes and rivers are ice-free; on the milder Pacific coast, they are permanent residents. [[Scandinavia]]n and [[Russia]]n birds also migrate southwards, but western European birds, and a few in [[Japan]], are largely resident.<ref name=Hoyo/><ref name=Madge/> In some populations, the males also show distinct moult migration, leaving the breeding grounds as soon as the young hatch to spend the summer (June to September) elsewhere. In particular, most of the Western European male population migrates north to estuaries in [[Finnmark]] in northern [[Norway]] (principally [[Tanafjord]]) to moult, leaving the females to care for the ducklings. Much smaller numbers of males also use estuaries in eastern [[Scotland]] as a moulting area.<ref name=Snow/><ref name=Little1985/><ref name=Hatton2004/>