The Common Chaffinch is a partial migrant - some stay while most head south.
Who stays: mainly males and birds in southern Sweden. Even Linnaeus noted that the winter flocks in Uppsala consisted mostly of males, which gave the species its Latin name coelebs ("bachelor").
Food: spilt grain and fallen seeds on stubble fields and under bird feeders, readily in mixed flocks.
Reinforcements: the number of overwintering birds varies from year to year depending on the beech mast crop.