Picchio rosso maggiore

Identificazione

An adult great spotted woodpecker is 20–24 cm (7.9–9.4 in) long, weighs 70–98 g (2.5–3.5 oz) and has a 34–39 cm (13–15 in) wingspan. The upperparts are glossy blue-black, with white on the sides of the face and neck. Black lines run from the shoulder to the nape, the base of the bill and about halfway across the breast. There is a large white shoulder patch and the flight feathers are barred with black and white, as is the tail. The underparts are white other than a scarlet lower belly and undertail. The bill is slate-black, the legs greenish-grey and the eye is deep red. Males have a crimson patch on the nape, which is absent from the otherwise similar females. Juvenile birds are less glossy than adults and have a brown tinge to their upperparts and dirty white underparts. Their markings are less well-defined than the adult's and the lower belly is pink rather than red. The crown of the juvenile's head is red, less extensively in young females than males.<p>The various subspecies differ in plumage, the general pattern being that northern forms are larger, heavier-billed and whiter beneath, as predicted by Bergmann's rule, so north Eurasian D. m. major and D. m. kamtschaticus are large and strikingly white, whereas D. m. hispanicus in Iberia and D. m. harterti in Corsica and Sardinia are somewhat smaller and have darker underparts. D. m. canariensis and D. m. thanneri in the Canary Islands are similar to the Iberian race but have contrasting white flanks. In Morocco, D. m. mauritanus is pale below with red in the centre of its breast, and birds breeding at higher altitudes are larger and darker than those lower in the hills. D. m. numidus in Algeria and Tunisia is very distinctive, with a breast band of red-tipped black feathers. Caspian D. m. poelzami is small, relatively long-billed and has brown underparts. D. m. japonicus of Japan has less white on its shoulders but more in its wings. The two Chinese forms, D. m. cabanisi and D. m. stresemanni, have brownish heads and underparts, and often some red on the breast. Both races have increasingly dark underparts towards the south of their respective ranges.<p>Some other species in its genus are similar to the great spotted woodpecker. The Syrian woodpecker lacks its relative's black cheek bar and has whiter underparts and paler red underparts, although juvenile great spotted woodpeckers often have an incomplete cheek bar, so can potentially be misidentified as Syrian. The white-winged woodpecker has a far more extensive white wing patch than the great spotted woodpecker. The Sind woodpecker is very similar to the Syrian species, and can be distinguished from great spotted woodpecker in the same way.<p>Adult great spotted woodpeckers have a complete moult after the breeding season which takes about 120 days. Northern D. m. major starts its moult from mid-June to late July and finishes in October or November, temperate races like D. m. pinetorum are earlier, commencing in early June to mid-July and completing in mid-September to late October, and southern D. m. hispanicus starts late May or June and finishes as early as August. Juveniles have a partial moult, retaining some of the wing coverts but replacing body, tail and primary feathers. This moult to near-adult plumage starts from late May to early August and finishes from mid-September to late November, timing varying with latitude as with the adults.<p>The call of the great spotted woodpecker is a sharp kik, which may be repeated as a wooden rattling krrarraarr if the bird is disturbed. The courtship call, gwig, is mostly given in the display flight. Drumming on dead trees and branches, and sometimes suitable man-made structures, serves to maintain contact between paired adults and to advertise ownership of territory.<p>Both sexes drum, although the male does so much more often, mostly from mid-January until the young are fledged. The far-carrying drumming is faster than for any other woodpecker in its range at around 10–16 strikes per second, typically in one-second bursts, although repeated frequently. As late as the early twentieth century it was thought that the drumming might be a vocalisation, and it was not until 1943 that it was finally proved to be purely mechanical.

Tassonomia

Woodpeckers are an ancient bird family consisting of three subfamilies, the wrynecks, the piculets and the true woodpeckers, Picinae. The largest of the five tribes within the Picinae is Melanerpini, the pied woodpeckers, a group which includes the great spotted woodpecker. Within the genus Dendrocopos the great spotted woodpecker's closest relatives are the Himalayan, Sind, Syrian, white-winged woodpeckers and the Darjeeling woodpecker. The great spotted woodpecker has been recorded as hybridising with the Syrian woodpecker.<p>The great spotted woodpecker was described by Carl Linnaeus in his landmark 1758 10th edition of Systema Naturae as Picus major. It was moved to its current genus, Dendrocopos, by the German naturalist Carl Ludwig Koch in 1816. The genus name Dendrocopos is a combination of the Greek words dendron , "tree", and kopos, "striking". The specific major is from Latin maior, "greater".<p>Recognised subspecies vary by author from as few as 14 to nearly 30. This is largely because changes are clinal with many intermediate forms. However, mitochondrial DNA data suggests that the Caspian Sea region's Dendrocopos major poelzami, Japanese D. m. japonicus and Chinese D. m. cabanisi may all merit full species status. Despite its distinctive appearance, D. m. canariensis from Tenerife in the Canary Islands appears to be closely related to the nominate subspecies D. m. major.<p>The fossil subspecies D. m. submajor lived during the Middle Pleistocene Riss glaciation (250,000 to 300,000 years ago) when it was found in Europe south of the ice sheet. It is sometimes treated as a distinct species, but did not differ significantly from the extant great spotted woodpecker, whose European subspecies are probably its direct descendants.

Nome scientifico

Dendrocopos major

Autorità

(Linnaeus, 1758)

Ordine

Piciformi

Famiglia

Picidae

Genere

Dendrocopos

Areale e habitat

The species ranges across Eurasia from Ireland to Japan, and in North Africa from Morocco to Tunisia; it is absent only from those areas too cold or dry to have suitable woodland habitat. It is found in a wide variety of woodlands, broadleaf, coniferous or mixed, and in modified habitats like parks, gardens and olive groves. It occurs from sea level to the tree line, up to 2,000 m (6,600 ft) in Europe, 2,200 m (7,200 ft) in Morocco and 2,500 m (8,200 ft) in Central Asia.<p>The great spotted woodpecker is mainly resident year-round, but sizeable movements can occur when there are shortages of pine and spruce cones in the north of the range. Highland populations often descend to lower altitudes in winter. Juveniles also have a tendency to wander some distance from where they were hatched, often as far as 100–600 km (60–400 mi), sometimes up to 3,000 km (1,900 mi). Vagrants have reached the Faroe Islands, Hong Kong and Iceland, and there are several sightings from North America in at least the Aleutian Islands, Pribilof Islands and Alaska.<p>Due to deforestation, this woodpecker was extirpated in Ireland in the seventeenth century, but the island has been naturally recolonised, with the first proven nesting in County Down in 2007. Its expansion in range is continuing, with breeding proven or suspected in at least 10 counties by 2013, with the main concentration in Down and County Wicklow. Genetic evidence shows the birds to be of British, rather than Scandinavian, ancestry, with the populations in Ireland and Northern Ireland having separate origins. The great spotted woodpecker was also found to have been nesting in the Isle of Man from 2009, and breeding from 2010.

Migrazione

Specie stanziale

Comportamento

Comportamento migratorio: Specie stanziale.

Conservazione

Tendenza della popolazione: in aumento.

Tendenza della popolazione

in aumento