Diversification and species limits in scale-backed antbirds (Willisornis: Thamnophilidae), an Amazonian endemic lineage Author Quaresma, Tânia Fontes Author Cronemberger, Áurea A. Author Batista, Romina Author Aleixo, Alexandre text Zoological Journal of the Linnean Society 2022 2022-04-20 196 4 1408 1430 http://dx.doi.org/10.1093/zoolinnean/zlac011 journal article 198844 10.1093/zoolinnean/zlac011 f0e41c8c-3c89-4a2d-a8e6-f74951ea1f40 0024-4082 7386680 1719CE06-0D0E-4E8E-94E8-37AC811AED10 WILLISORNIS VIDUA VIDUA ( HELLMAYR, 1905 ) Taxonomy Genetic lineages with plumage characteristics discussed below can be assigned to W. v. vidua ( type locality: Igarapé-Açu , state of Pará , in the Belém area of endemism; Peters, 1951 ) . Plumage attributes Males similar to W. v. nigrigula overall, but without a black throat patch. Ventral region grey, with lighter throat. Females are also similar to those in W. v. nigrigula , but with the white interscapular spot absent or inconspicuous. Genetic differentiation Specimens with the plumage characteristics above belong to a genetic group with some geographic structuring recovered for the mitochondrial genes across the Tocantins River and which are referred herein as W. v. vidua A and W. v. vidua B. These groups are completely sorted for their mitochondrial DNA, but less so for the nuclear genes, occupying together the area comprised between the east bank of the Xingu eastward to Maranhão in easternmost Brazilian Amazonia (Fig. 1). Plumage variation We did not detect any conspicuous geographic variation in plumage that could be related to the comparatively shallow level of genetic structure recovered within this group.