This morning at Kellys, a display by the L Grassbird, while calling. I would call this ‘wing-trembling’ rather than ‘fluttering’ because the wings are held extended, not beaten. It looked like courtship to me, although only the single bird in view. HANZAB mentions a wing-fluttering ‘apparent territorial dispute’ with ‘deep wingbeats’. Social behaviour is ‘not well known’ and difficult to observe. There is another record of two birds ‘facing each other, drooping and fluttering wings … probably agonistic and not sexual behaviour as claimed’. It is a single bird in the below composite
