Picchio dorato settentrionale

Identificazione

Adults are brown with black bars on the back and wings. A mid- to large-sized northern flicker measures 28–36 cm (11–14 in) in length and .mw-parser-output .frac{white-space:nowrap}.mw-parser-output .frac .num,.mw-parser-output .frac .den{font-size:80%;line-height:0;vertical-align:super}.mw-parser-output .frac .den{vertical-align:sub}.mw-parser-output .sr-only{border:0;clip:rect(0,0,0,0);clip-path:polygon(0px 0px,0px 0px,0px 0px);height:1px;margin:-1px;overflow:hidden;padding:0;position:absolute;width:1px}42–54 cm (16+1⁄2–21+1⁄2 in) in wingspan. The body mass can vary from 86 to 167 g (3 to 5+7⁄8 oz). Among standard scientific measurements, the wing bone measures 12.2–17.1 cm (4+13⁄16–6+3⁄4 in), the tail measures 7.5–11.5 cm (3–4+1⁄2 in), the bill measures 2.2–4.3 cm (7⁄8–1+11⁄16 in) and the tarsus measures 2.2–3.1 cm (7⁄8–1+1⁄4 in). The largest-bodied specimens are from the northern stretches of the species' range at the latitude of Alaska and Labrador, while the smallest specimens come from Grand Cayman Island. A necklace-like black patch occupies the upper breast, while the lower breast and belly are beige with black spots. Males can be identified by a black (in the eastern part of the species' range) or red (in the western part) mustachial stripe at the base of the beak, while females lack this stripe. The tail is dark on top, transitioning to a white rump which is conspicuous in flight. Subspecific plumage is variable.<p>This bird's call is a sustained laugh, ki ki ki ki, quite different from that of the pileated woodpecker (Dryocopus pileatus). One may also hear a constant knocking as they often drum on trees or even metal objects to declare territory. Like most woodpeckers, northern flickers drum on objects as a form of communication and territory defense. In such cases, the purpose is to make as loud a noise as possible, so woodpeckers sometimes drum on metal objects.<p>Like many woodpeckers, its flight is undulating. The repeated cycle of a quick succession of flaps followed by a pause creates an effect comparable to a roller coaster.

Tassonomia

The English naturalist Mark Catesby described and illustrated the northern flicker in his book The Natural History of Carolina, Florida and the Bahama Islands which was published between 1729 and 1732. Catesby used the English name "Gold-winged Wood-pecker" and the Latin Picus major alis aureis. When in 1758 the Swedish naturalist Carl Linnaeus updated his Systema Naturae for the tenth edition, he included the northern flicker, coined the binomial name Cuculus auratus and cited Catesby's book. The specific epithet auratus is a Latin word meaning "gilded" or "ornamented with gold". The type locality is South Carolina. The northern flicker is one of 13 extant New World woodpeckers now placed in the genus Colaptes that was introduced by the Irish zoologist Nicholas Aylward Vigors in 1825 with the northern flicker (Colaptes auratus) as the type species.<p>Ten subspecies are recognized, one of which is now extinct, though it may be invalid. The extant subspecies were at one time considered subspecies of two separate species called the yellow-shafted flicker (C. auratus, with four subspecies) and the red-shafted flicker (C. cafer, with six subspecies, five living and one extinct), but they commonly interbreed where their ranges overlap and are now considered one species by the American Ornithologists Union. This is an example of what is referred to in science as the species problem.

Nome scientifico

Colaptes auratus

Autorità

(Linnaeus, 1758)

Ordine

Piciformi

Famiglia

Picidae

Genere

Colaptes

Areale e habitat

The northern flicker may be observed in open habitats near trees, including woodlands, edges, yards, and parks. In the western United States, one can find it in mountain forests all the way up to the tree line. The northern flicker generally nests in holes in trees like other woodpeckers. Occasionally, it has been found nesting in old, earthen burrows vacated by belted kingfishers (Megaceryle alcyon) or sand martins (Riparia riparia). Both sexes help with the nest excavation. The entrance hole is about 8 cm (3 in) in diameter, and the cavity is 33–41 cm (13–16 in) deep. The cavity widens at the bottom to make room for the eggs and the incubating adult. Inside, the cavity is bare except for a bed of wood chips for the eggs and chicks to rest on. Once the nestlings are about 17 days old, they begin clinging to the cavity wall rather than lying on the floor. They can create cavities inside homes, especially homes of stucco or weak wooden siding.

Migrazione

Complete migrants

Conservazione

Tendenza della popolazione

declining