Minatore comune

Identificazione

The common miner is a medium-size member of its genus. It is 14 to 17 cm (5.5 to 6.7 in) long and weighs 20 to 34 g (0.71 to 1.2 oz). The sexes are alike. The nominate subspecies G. c. cunicularia has a pale brownish face with a wide whitish supercilium and a vague darker "moustache" and line behind the eye. It has a dull grayish brown crown and upperparts; the former has dark brown spots. Its uppertail coverts are dull grayish brown with pale brownish tips. Its tail feathers have buff-whitish bases and blackish ends with pale rufescent between them. The pale area is progressively larger from the innermost to the outer feathers and the outermost have almost entirely white outer webs. Dull brownish wing coverts with pale buff tips form distinct wing bars. Its flight feathers are dull brownish with a wide pale rufous band. Its throat is whitish, its breast buff-white with wavy brownish streaks, its belly pale buffy whitish with a pale cinnamon tinge on the flanks, and its undertail coverts whitish. Its iris is brown to yellowish brown, its medium-length bill is black to brown with sometimes a pale base to the mandible, and its legs and feet are dark gray to black.<p>The other subspecies of the common miner differ from the nominate and each other thus:

Tassonomia

Taxonomists assign these nine subspecies to the common miner:<p>Subspecies G. c. juninensis, G. c. titicacae, and G. c. frobeni might instead be members of a separate species. Subspecies G. c. georgei and G. c. deserticolor might also be members of another separate species.<p>Among members of genus Geositta, the common miner is most closely related to the slender-billed miner (G. tenuirostris).

Nome scientifico

Geositta cunicularia

Autorità

(Vieillot, 1816)

Ordine

Passeriformi

Famiglia

Furnariidae

Genere

Geositta

Areale e habitat

The subspecies of the common miner are found thus:<p>Though the International Ornithological Committee includes Paraguay in the range of cunicularia, the South American Classification Committee of the American Ornithological Society has no records in that country.<p>The common miner inhabits open landscapes including puna and temperate grasslands, arid lowland scrublands, and moister restinga scrublands. Most are flat to gently sloping and have sandy soils, short grass, and scattered rocks and shrubs. The species' distribution tends to be patchy. In elevation it ranges from sea level to 5,000 m (16,000 ft).

Migrazione

Complete migrants

Comportamento

The Andean subspecies of the common miner appear to be mostly year-round residents but make some movement downslope after the breeding season. G. c. hellmayri moves north after breeding. The southern subpopulation of the nominate G. c. cunicularia also moves north but the division between it and the resident more northerly subpopulation is unclear.<p>The common miner forages singly or in pairs. It gleans food from the ground while hopping, not walking. Its diet is mostly arthropods including adult and larval flies and beetles; seeds are a minor component.<p>The common miner breeds in the austral summer, generally between September and December. It is thought to be monogamous. It excavates a horizontal tunnel with an enlarged chamber at the end in an earthen bank or slope, and pads the chamber with grass, hair, feathers, and other soft material. The clutch size is two or three eggs and both parents incubate them and provision the nestlings.<p>The common miner sings during a display flight. The nominate subspecies's song is two notes sounding like "ta whit-ta whit" and its flight call is "a nasal 'dee-dijer' or 'er?' ". The other subspecies sing "a loud, shrill...'de-dirr-rr-rrr' " and their flight calls are "a high-pitched 'keep' or rich, sweet 'pip' ". All subspecies make trilled notes as well.

Conservazione

Tendenza della popolazione

declining