The Green ‘Yaffle’
The green woodpecker is the largest of our three British species of woodpeckers, and the most colourful. Unlike the two smaller species it is not a frequent drummer, but you can recognise its call among the trees for it sounds just like someone laughing.
Of the three woodpecker species in Britain the great spotted and less common lesser spotted are black and white; in length they are about 23cm (9in) and 14.5cm (5-1/2in) respectively. But the green woodpecker, as its name implies, is mainly green; and it is comparatively large at about 32cm (12in) long. At a distance it appears generally green. But closer examination reveals that its back is darker than its bullish green belly, and that its rump is bright greenish yellow. The crown is a contrasting crimson, and the sexes can be distinguished by looking at the moustache-like stripe, which is all black in the female but is red with a black border in the male. Young birds are less brightly coloured, with pale spots on the green and black streaked underside.
The green woodpecker is a resident bird, rarely undertaking journeys of more than a few kilometres. This may explain why it has not colonized Ireland. It has only recently invaded the Lake District and Scotland. In Scotland, breeding was first recorded in 1951 and the invasion was two-pronged. Birds from north-west England moved into the counties across the Solway Firth, while their range in the north-east extended from Northumberland to the central lowlands of Scotland and up to Aberdeen on the east coast. Their progress northwards may still continue in future.
Green woodpeckers prefer open (and often deciduous) woodland to the denser stands of conifers. The open parklands and landscaped gardens that man has created in much of Britain are particularly favoured, so that people who regularly walk in such areas are familiar with the bird. It also commonly visits bird tables, and in doing so it adds conspicuous dashes of colour, appearing suddenly and moving jerkily in its yellow, green and red plumage.
Its long and highly manoeuvrable tongue is useful for searching under loosened bark for grubs, but the green wood-pecker also uses it to probe into short turf, or into ant hills, in search of the abundance of food that these contain. In recent decades a number of open conifer woods have reached maturity in Scotland; these are inhabited by dense populations of wood ants, and this may have been one factor that made it possible for green woodpeckers to invade Scotland.
Ants are significant because they help to extend the range of the green woodpecker. But the birds have an extremely varied diet. They eat a large number of tree-inhabiting insects, especially the larvae of wood-boring beetles and gall-producing insects, and many caterpillars as well. Green woodpeckers have also been known to prey on other birds, especially nestlings, Tits, house martins, house sparrows, starlings and even lesser spotted woodpeckers are occasionally eaten. They also eat eggs as well as acorns, hazel nuts, rowan berries and a variety of other seeds, berries and fruits.
New nests each year
Out of the breeding season, green woodpeckers continue to use tree holes for roosting at night; one member of the pair roosts in the former nest hole, and the other bores a new hole which it uses solely as a roost. Even though the birds have kept the previous year’s nest hole in use throughout the winter, they generally bore a new one for nesting each spring.
Both the male and female take part in the work of boring the nest hole. They normally cut their holes in decaying, rather than living, timber, although they often use decaying branches of living trees. The nest contains no lining material, except for a few wood chips that the birds do not remove. And the eggs are laid directly on the floor of the cavity. The eggs are white and oval, and normally number between five and seven.
Green woodpeckers breed between the end of April and June, but starlings pose a serious threat to those that nest early in the season. The starlings, in their search for convenient nesting places, evict the woodpeckers forcibly from their hole, and proceed to occupy it themselves. In nests that escape these most unwelcome visitors, the green woodpeckers (both male and female) incubate their eggs for 15-17 days. After hatching, both parents feed the young, and it is during this period (about 20 days) that you can most easily detect a green woodpecker nest by the raucous calling of the noisy young.
Woodpeckers and man
It may seem surprising that woodland birds such as green wood-peckers should have an important effect on the activity of man, but their habit of boring holes does cause difficulties. They sometimes damage shingle roofs by boring into joists and weakening them at least enough to cause a partial collapse. Telegraph poles, being made of dead wood, have obvious attractions for green woodpeckers; and wherecables are carried by wooden poles, the birds can damage them sufficiently to bring them down and cause a power failure.
On the credit side, some foresters believe that the green woodpecker is useful in removing insect pests from trees. Besides this, their preference for boring into decaying wood provides an early warning system for the forester – their activity shows him where to cut off dying branches. To the wider public, their colours and laughing call bring excitement to gardens and town parks.