It is solitary, but sometimes form mixed-species flocks.

Several evolutionary mechanisms have been proposed to explain the formation of mixed-species flocks.

They normally do not take part in mixed-species flocks.

Though it sometimes joins mixed-species flocks, the Red Warbler is more typically found alone or in pairs.

It feeds actively in the midst of mixed-species flocks when they pass.

The bird is often seen close to the tree line, and likes to feed in mixed-species flocks in winter.

It is usually seen in pairs or mixed-species flocks.

It may join mixed-species flocks after breeding season for foraging.

The jays travel in groups of two to ten individuals and may join mixed-species flocks.

They participate in mixed-species flocks during the non-breeding season.