The commonest call is a hard, chattering "tjack-tjack-tjack" that is heard constantly from flying and resting flocks. The song is less striking — a rambling, crackling and twittering series that lacks the resonant fluting notes of the other thrushes. The rattling flock call is almost always the first sign that Fieldfares are in the area, especially in autumn and winter when large flocks roam about. At the nest the chatter is joined by a sharp, nasal alarm call that the whole colony takes up when a bird of prey approaches.