|Image courtesy RSPB|
In winter many birds flock together to feed. Without the need to defend territories for breeding, there is safety in numbers, and winter flocks often consist of several different species all seeking food together. Goldfinches love thistle seeds; I don't think we have any in the garden, but perhaps they found some other seed-bearing plants to feast on.
In contrast, robins will defend a territory all year round – both males and females. Last night I was walking our dog at dusk, just as the street lights were coming on. On every street, it seemed, the liquid notes of a robin filtered down from a leafless tree. Some people say their song is less strident, more melancholy in winter, and last night I was inclined to agree.