Willisornis poecilinotus subsp. duidae (Chapman, 1923)

Quaresma, Tânia Fontes, Cronemberger, Áurea A., Batista, Romina & Aleixo, Alexandre, 2022, Diversification and species limits in scale-backed antbirds (Willisornis: Thamnophilidae), an Amazonian endemic lineage, Zoological Journal of the Linnean Society 196 (4), pp. 1408-1430 : 1418-1419

WILLISORNIS POECILINOTUS DUIDAE

( CHAPMAN, 1923)

Taxonomy

Genetic lineages possessing the plumage attributes discussed below can be unequivocally assigned to W. p. duidae (type locality: ‘ Mount Duida, Amazonas, Venezuela’ ; Peters, 1951), distributed in north-western

Amazonian Brazil, southern Venezuela and eastern Colombia ( Gill et al., 2022).

Plumage attributes

Males similar to W. p. poecilinotus , but distinguished by an overall darker colour, both in the dorsal and ventral regions. Females distinguished from those in any other Willisornis taxon by an intense rufous colour below, with a slightly paler quality in the upperparts. ‘Lace’ similar to those in males (i.e. in black-white colour). Tail rufous as well, with terminal and intermediate white dots.

Genetic differentiation

Specimens with the plumage characteristics above belong to three distinct and closely related genetic lineages that are completely sorted for their mtDNA, but less so for the nuclear genes and which are distributed from both sides of the Middle and Upper Rio Negro , all the way to the north bank of the Amazonas / Solimões (Fig.1). The three lineages within this group were named W. p. duidae A, W. p. duidae B, W. p. duidae C and appear to replace each other across the Japurá / Caquetá and Içá rivers (Fig. 1). Interestingly, four specimens sequenced from northern Peru obtained from the north bank of the Amazon and Napo rivers (and previously attributed to W. p. lepidonota ; Isler & Whitney, 2011) also clustered in this lineage (see Discussion below) .

Plumage variation

Females of W. p. duidae C (which extends from northernmost Brazil to northern Peru on the north bank of the Amazonas and Napo rivers) have a lighter brown colour, less intense than in the other females of W. p. duidae A and B, and approaching those in W. p. gutturalis . Males belonging to W. p. duidae C are similar to those in W. p. duidae A and W. p. duidae B.