Slender-billed Miner

The slender-billed miner is a large member of its genus. It is 16 to 18 cm (6.3 to 7.1 in) long and weighs 32 to 38 g (1.1 to 1.3 oz). The sexes are alike. The nominate subspecies has a pale buffy brownish face with a whitish supercilium, a dark brownish stripe behind the eye, and a vague darker "moustache". It has a dull brown crown with wavy streaks, dull grayish brown upperparts, and slightly paler rump and uppertail coverts. Its central pair of tail feathers are dull brown with darker ends. The rest progress outward with less and less dark at the ends and more rufescent at their base to the outermost two pairs' rufous with some pale cinnamon. Dark brown wing coverts with dark buff tips form distinct wing bars. Its flight feathers are dark dusky with some rufous. Its throat is whitish, its breast buff-white with wavy brownish streaks, its belly pale buffy whitish, and its undertail coverts pale tawny. Its iris is dark brown, its long decurved bill is blackish with a pinkish base to the mandible, and its legs and feet black. Subspecies G. t. kalimayae is smaller and grayer than the nominate with darker wings and tail and more streaks on its breast.

The nominate subspecies of the slender-billed miner is by far the more widely distributed of the two. It is found on both slopes of the Andes of Peru almost from the border with Ecuador south through the Andes of Bolivia into northwestern Argentina as far as Tucumán Province. G. t. kalimayae is found disjunctly in central Ecuador's Cotopaxi Province. The species inhabits puna grass- and scrublands, pastures, and cultivated land; it is often found near water. In elevation it ranges between 2,500 and 4,600 m (8,200 and 15,100 ft).

The slender-billed miner forages on the ground, gleaning, probing, and excavating for invertebrates. Its diet includes beetles, butterflies and moth larvae, spiders, and springtails.