Fig 1.
Location and haplotype networks of 112 genetic samples of Thraupis.
(A) Taxonomic identification and geographic distribution of the genetic samples of Thraupis included in this study. Green and lilac areas show the distribution of T. episcopus and T. sayaca, respectively. Haplotype network of (B) the mitochondrial markers ND2 and cyt-b, (C) TGFB2, (D) MUSK, and (E) BF5 from the tissues referenced in Fig 1A. Red circles in the mitochondrial haplotype network highlight haplotype clusters and were named after the taxa with nomenclatural priority in the cluster but do not represent a single subspecies (i.e., the episcopus group includes several subspecies). Maps in this figure were made using the free software Qgis v.3.10.7 and free data layers from DIVA-GIS (https://www.diva-gis.org/) and distribution polygons from IUCN red list webpage [53, 54]. Tanager illustrations made by Fernando Ayerbe-Quiñones.
Table 1.
Specimens with gene tree conflicts between mitochondrial and nuclear markers.
Names in bold indicate specimens that clustered within a clade that differed from plumage-based assignments from museum identifications.
Fig 2.
Phylogenetic relationships within Thraupis and geographic distribution of the genetic structure within the episcopus-sayaca complex.
(A) Phylogenetic relationships of Thraupis. Names in brackets represent subspecies groups, with the name corresponding to the taxon with nomenclatural priority within each genetic cluster (i.e., a single group can include several subspecies). Thickness of the branches is associated with the posterior probability value on the corresponding node. (B) STRUCTURE results of the episcopus-sayaca complex, specimens in group 2 represents the putative hybrids (Table 1), best supported K = 3. (C) Geographic distribution of the episcopus-sayaca complex. Colored circles represent different lineages in the species tree and groups in the STRUCTURE plots. Orange triangles represent genotypically inconsistent specimens (Table 1), presumed to be hybrids between episcopus and sayaca. Color continuum from withe to black represent changes in elevation (withe = 0 m, black ≥ 2500 m). Maps in this figure were made using the free software Qgis v.3.10.7, free data layers from DIVA-GIS (https://www.diva-gis.org/). Tanager illustrations by Fernando Ayerbe-Quiñones.
Fig 3.
Linear Discriminant Analysis (LDA) of morphometric traits within the episcopus-sayaca species complex.
Coefficients of linear discriminants for LDA1 are: -6.557557*Weight + 7.451838*CN + 1.987242*CT + 3.975692*TS + 16.869735*Wing + 2.702621*Tail. Coefficients of linear discriminants for LDA2 are: 14.460641*Weight + 1.987242*CN—4.708751*CT + 15.982253*TS—11.342798*Wing—1.458385*Tail. Individuals marked with gray dots were identified with a posterior probability of 0.9 or higher and represent 6.1% of the birds. Individuals marked with black dots were identified with a posterior probability of 0.5 or lower and represent 19.2% of the birds.
Fig 4.
Geographic distribution of wing-patch color in the episcopus-sayaca species complex.
Each symbol represents a photographed specimen of T. episcopus (circles), T. sayaca (squares), or intermediate specimens (triangles). Symbol colors denote the actual color of the wing patch, as extracted from photography with the HTML code. Pink crosses represent the type locality of each subspecies. Color scale from black to withe represent changes in elevation (black = 0 m, white ≥ 3000 m). Maps in this figure were made using the free software Qgis v.3.10.7 and free data layers from DIVA-GIS (https://www.diva-gis.org/).
Fig 5.
Morphological variation in the episcopus-sayaca complex and a presumed T. episcopus x T. abbas hybrid.
(A) typical specimen of T. episcopus from the western side of the Andes. (B—D) intermediate individuals between western and eastern populations of T. episcopus in Colombia and Venezuela Llanos, showing the color variation of intermediate individuals. (E) Representative bird from eastern of the Andes, although this is the most morphologically variable group. (F—G) specimens of T. episcopus x T. sayaca morphological and molecular hybrids, with intermediate colors in the wing patch. (H). The typical phenotype of T. sayaca, and (I) presumed T. episcopus x T. abbas hybrid next to (J) a typical T. abbas individual.