European green woodpecker lower black border to the moustache. Juveniles are spotty and streaked all over; the moustache is dark initially, though juvenile males can show some red feathers by early June or usually by July or August. Moult takes place between June and November with the first flight feathers being lost around the time the young fledge. Juveniles moult quickly after fledging and gain their adult plumage between August and November. Although the European green woodpecker is shy and wary, it is usually its loud calls, known as yaffling, which first draw attention. It 'drums' rarely (a soft, fast roll), but often
European green woodpecker gives a noisy "kyü-kyü-kyück" while flying. The song is a loud series of 10-18 'klü' sounds which gets slightly faster towards the end and falls slightly in pitch. The female makes a thinner "pü-pü-pü-pü-pü-pü-pü". The flight is undulating, with 3–4 wingbeats followed by a short glide when the wings are held by the body. It can be distinguished from the similar, but smaller, grey-headed woodpecker by its yellowish, not grey, underparts, and the black lores and facial 'mask'. In Europe, its green upperparts and yellow rump can lead to confusion with the grey-headed woodpecker or possibly the female golden oriole,