Chaco Earthcreeper Tarphonomus certhioides Scientific name definitions

The Chaco Earthcreeper is the more widespread and southern member of the species pair that comprises Tarphonomus. It is found from E Bolivia south through W Paraguay and throughout central Argentina to the northern edge of Patagonia. In takes various arid shrubby habitats, or even light woodland and espinal habitats; in the north it prefers areas with ground bromeliads, but these are absent in the south of its range. This is a relatively dark species with a well marked and contrasting white throat. The Chaco Earthcreeper also shows a rufous forehead and dark belly, it is darker in the south than in the north, and in the south it shows a buffy supercilium that is absent in the north. Up until recently Tarphonomus was included in Upucerthia, but the two are not closely related; visually these are shorter and straighter-billed species than Upucerthia, and their voices are made up of slow and ringing notes, quite unlike the more trilled and strident voices of Upucerthia. The Chaco Earthcreeper forages on the ground and in shrubs, it seldom cocks its tail.

16 cm; 18–31 g. Small earthcreeper with long, very slightly decurved bill  . Nominate race has indistinct orange-rufous supercilium, messy dark brown loral region and auriculars; forehead dull orange-rufous, blending to dull dark brownish crown and back; rump and uppertail-coverts slightly more rufescent; wings slightly more rufescent than back, base of remiges rufous; tail rounded, rufescent brown, dullest on central feather pair, progressively more rufous towards outer feathers; throat and malar area white, underparts dull brown, rufescent flanks and undertail-coverts; iris brown; upper mandible blackish to dark grey, lower mandible slate-grey to pinkish-grey; tarsus and toes blackish to dark grey. Sexes alike. Juvenile is tinged rufous throughout, rufous of forehead less conspicuous. Race <em>estebani</em> is paler on back  , duller on breast and belly, lacks rufescent tinge on flanks; luscinia has greyer, less rufescent upperparts, more extensive rufous on wings, paler underparts.

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Editor's Note: Additional distribution information for this taxon can be found in the 'Subspecies' article above. In the future we will develop a range-wide distribution article.

Song a series of 5–15 loud, squeaky penetrating “chiqui” notes that increase in intensity, descend in pitch; call  a loud whistled “tééoo” or “tuéét”.