Common miner

Not to be confused with common myna.

Common miner
Conservation status
Least Concern  (IUCN 3.1)
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Aves
Order:	Passeriformes
Family:	Furnariidae
Genus:	Geositta
Species:	G. cunicularia
Binomial name
Geositta cunicularia (Vieillot, 1816)

The common miner (Geositta cunicularia) is a passerine bird in the subfamily Sclerurinae, the leaftossers and miners, of the ovenbird family Furnariidae. It is found in Argentina, Bolivia, Brazil, Chile, Peru, and Uruguay.

Taxonomy and systematics

Taxonomists assign these nine subspecies to the common miner:

• G. c. juninensis Taczanowski, 1884
• G. c. titicacae Zimmer, JT, 1935
• G. c. frobeni (Philippi & Landbeck, 1864)
• G. c. georgei Koepcke, 1965
• G. c. deserticolor Hellmayr, 1924
• G. c. fissirostris (Kittlitz, 1835)
• G. c. contrerasi Nores & Yzurieta, 1980
• G. c. hellmayri Peters, JL, 1925
• G. c. cunicularia (Vieillot, 1816)

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.

Among members of genus Geositta, the common miner is most closely related to the slender-billed miner (G. tenuirostris).

Description

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.

The other subspecies of the common miner differ from the nominate and each other thus:

• G. c. titicacae: larger, paler, and buffier; creamier tail base; less distinct streaks on breast
• G. c. juninensis: paler and buffier than titicacae; few to no breast streaks
• G. c. frobeni: buffy white uppertail coverts; whitish tail base; whiter underparts than juninensis
• G. c. deserticolor: smaller and paler than frobeni; gray uppertail coverts
• G. c. georgei: like deserticolor but darker wings and tail; pale yellowish buff underparts; heavier breast streaks
• G. c. fissirostris: slightly grayer above and whiter below than nominate; darker chest markings
• G. c. hellmayri: like fissirostris but whiter uppetail coverts, paler tail base, and paler chest markings
• G. c. contrerasi: smallest but overlaps with hellmayri; blackish wings and tail are darkest of all; creamy buff underparts; dark brownish or blackish spots on breast

Distribution and habitat

The subspecies of the common miner are found thus:

• G. c. juninensis: Andes of central Peru's departments of Junín and Huancavelica
• G. c. titicacae: Andes of southern Peru, Bolivia east to Cochabamba Department, northern Chile to the Tarapacá Region, and northwestern Argentina to Mendoza Province
• G. c. frobeni: Pacific slope of the Andes in southern Peru between Arequipa and Tacna departments
• G. c. georgei: coastal Peru's Ica and Arequipa departments
• G. c. deserticolor: coastally from Arequipa Department in Peru south to Chile's Atacama Region
• G. c. fissirostris: central Chile from coastal Atacama to Los Lagos regions and east to the Andean foothills
• G. c. contrerasi: Sierras Grandes in Argentina's Córdoba Province
• G. c. hellmayri: Andes of central Chile and southwestern Argentina (south of titicacae)
• G. c. cunicularia: lowlands of extreme southeastern Brazil, Uruguay, eastern Argentina, and southern Chile south to Tierra del Fuego

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.

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).

Behavior

Movement

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.

Feeding

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.

Breeding

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.

Vocalization

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.

Status

The IUCN has assessed the common miner as being of Least Concern. It has a very large range, but its population size is not known and is believed to be decreasing. No immediate threats have been identified. In habitats with light to moderate human disturbance it is considered common to locally abundant. It occurs in several protected areas. However, in southeastern Brazil coastal development may become a threat.

Further reading

• Harris, Graham (1998) A Guide to the Birds and Mammals of Coastal Patagonia, Princeton University Press.
• Grosset, Arthur (2007) Common Miner: Geositta cunicularia.
• Jaramillo, Alvaro; Burke, Peter & Beadle, David (2003) Field Guide to the Birds of Chile, Christopher Helm, London