Systematics

Seven subspecies are recognized, though individual and age-related variation in phenotype complicate efforts to delineate subspecies. For example, lineaticeps, littoralis, and uaireni are poorly differentiated from one another, and the nominate subspecies and esmeraldae may represent extremes in a cline.

guerrerensis, described as Lepidocolaptes souleyetii guerrerensis van Rossem 1939 – W Mexico (Sierra Madre del Sur, in Guerrero and SW Oaxaca).

compressus, described as Thripobrotus compressus Cabanis 1861 – lowlands on both slopes of Middle America from S Mexico (S Veracruz, SW Campeche, SW Chiapas) S to W Panama (E Chiriquí, W Bocas del Toro).

lineaticeps, described as Picolaptes lineaticeps Lafresnaye 1850 – C & E Panama (E from Canal Zone), N & E Colombia (except Santa Marta region) and W Venezuela (Táchira, W Mérida, extreme W Barinas).

littoralis, described as Picolaptes albolineatus littoralis Hartert and Goodson 1917 – NW Colombia (Santa Marta region, Atlántico), N & C Venezuela (NW Zulia E to Sucre, S to Orinoco region), Guyana and extreme N Brazil (upper R Branco); also Trinidad.

uaireni, described as Lepidocolaptes souleyetii uaireni Phelps and Phelps 1950 – Known only from type locality on R Uairén, in extreme SE Venezuela (SE Bolívar).

esmeraldae, described as Lepidocolaptes souleyeti [sic] esmeraldae Chapman 1923 – SW Colombia (Nariño) and W Ecuador (S through most of El Oro).

souleyetii, described as Dendrocolaptes Spuleyetii Des Murs 1849 – SW Ecuador (S El Oro, Loja) and NW Peru (S to Lambayeque).

From Marantz et al (2003): "… Race esmeraldae is like nominate, but throat and streaking below are a deeper buff in colour, streaks with less pronounced dusky margins, bill shorter. Races lineaticeps, littoralis and uaireni are also similar to nominate, but with upper mandible dark brownish, streaks on crown and underparts narrower, lower throat finely streaked dusky, and rufous of rump, wings and tail darker; littoralis differs from lineaticeps mainly in its smaller size, but also on average paler and less rufescent above, lighter and more buffy below; uaireni is darker above and below than either lineaticeps or littoralis, with throat and streaking on both crown and underparts more whitish (less buffy), crown streaks narrower, streaks below with blacker margins; compressus is like lineaticeps but darker, with broader streaking above and below, with streaks on back more extensive and often with dark margins, throat pale buff to whitish, variable, streaking sometimes even broader and throat darker buff ("insignis"); guerrerensis is slightly larger and somewhat paler than compressus (lighter red above, greyer below)".

The genus Lepidocolaptes is monophyletic (Derryberry et al. 2011, Arbelaez-Cortes et al. 2012), but relationships within the genus are not well resolved. Arbelaez-Cortes et al. (2012) recovered souleyetii as basal to a clade that included L. squamatus (Scaled Woodcreeper), L. falcinellus (Scalloped Woodcreeper), L. lacrymiger (Montane Woodcreeper), L. leucogaster (White-striped Woodcreeper), and L. affinis (Spot-crowned Woodcreeper), whereas Derryberry et al. (2011) reported that souleyetii was basal to a different clade, composed of L. "albolineatus" (= L. fuscicapillus, Rondonia Woodcreeper) and L. angustirostris (Narrow-billed Woodcreeper).