Green woodpeckers seldom 'drum'on trees as do others species of woodpeckers; however, they are more likely to do this in the breeding season between April and August. The 'drumming' is actually a contact call, made by the bird hammering its bill on branches. During the winter male and female green woodpeckers live separately but stay in the nesting area all year round. In spring, the birds call loudly and begin to visit each other. During courtship, the male flies in a spiral fashion round tree branches. When males fight over a female they sway their heads from side-to-side, wings spread out, tails fanned and crests raised.
Sometimes one of the winter roost holes is chosen for nesting. If not, the pair spends 10-30 days excavating a new hole in a tree trunk. When the nest is ready, the female lays five to seven small white eggs. The nest is unlined.
Both male and female share the incubation of the eggs, which takes 17-19 days, and they both feed the young for about 19 days. When the brood leaves the nest the parents may split up, each caring for 3 or 4 youngsters until they can fend for themselves. The young woodpeckers can fly within three or four weeks after hatching. They are capable of breeding at a year old.Read More: Green Woodpeckers and Humans