Synallaxis dissors, J. T. Zimmer, 1935

Stopiglia, Renata, Barbosa, Waleska, Ferreira, Mateus, Raposo, Marcos A, Dubois, Alain, Harvey, Michael G, Kirwan, Guy M, Forcato, Giovanna, Bockmann, Flavio A & Ribas, Camila C, 2022, Taxonomic challenges posed by discordant evolutionary scenarios supported by molecular and morphological data in the Amazonian Synallaxis rutilans group (Aves: Furnariidae), Zoological Journal of the Linnean Society 195 (1), pp. 65-87 : 82-83

SYNALLAXIS DISSORS J.T. ZIMMER, 1935

Synallaxis rutilans dissors Zimmer, 1935: 4

(holotype AMNH 248587 , an adult male from Campos Salles , Manaus, Amazonas, Brazil, examined by us) .

Diagnosis: Synallaxis dissors differs from S. omissa in having the forehead, supercilium and face amber (36). Compared to S. caquetensis , S. dissors differs in having the upperparts and crown olive brown (28) or Vandyke brown (121). Synallaxis dissors cannot be diagnosed morphologically compared to S. rutilans and S. amazonica , because the brown pattern of S. dissors is also present to a greater or lesser extent in S. rutilans and S. amazonica .

Description: Throat sepia (119); breast amber (36), varying individually between chestnut (32) and robin rufous (340); abdomen and flanks olive brown (28), varying individually between clay colour (26) and raw umber (123), with elements of raw umber (123) as the secondary colour; rectrices sepia (119); back and crown vary individually between olive brown (28) and Vandyke brown (121), with some raw umber (123) and Proust’s brown (121A) elements as the secondary colour; forehead, supercilium and face amber (36), varying individually to chestnut (32); wing-coverts chestnut (32), varying individually to amber (36); remiges Vandyke brown (121), varying individually to Vandyke brown (221); bill length 12.1–14.8 mm; bill depth 3.8–5.1 mm; wing length 51.8–63.5 mm; tail length 56.0– 74.5 mm, with ten rectrices (see Tables 7, 8).

Distribution: Southern Venezuela, French Guiana, Suriname, Guyana and in Brazil from the left bank of the Negro River, across the states of northern Amazonas, Roraima, northern Pará and Amapá. The distribution of Synallaxis dissors is represented in Figures 1 and 4 by the purple colour of the Guiana AE.

Figures

Figure 1. Map showing the distribution of sequenced individuals, phylogenetic time tree and plumage analyses for the Synallaxis rutilans group. The areas of endemism recognized by Silva et al. (2005) are highlighted on the map, and distribution points are numbered in accordance with individuals in the tree. The phylogenetic time tree is based on 1539 bp of concatenated ND2 and COI genes. Posterior probability values and the 95% HPD are indicated at each node. Thr, throat; Rec, rectrices; For, forehead; Sup, supercilium; Fac, face; Win, wing-coverts; Rem, remiges; 1st, first colour (main colour); 2nd, second colour (variation ±); 36 (e.g.), colours in Smithe’s catalogue; *, specimen damaged or immature; **, specimen analysed without Smithe’s catalogue; MPEG A, spirit collection specimen; dark grey circles in map and patches in table, specimens with grey plumage pattern; light grey circles and patches, specimens with olive plumage pattern; black circles and patches, specimens with rufous plumage pattern; purple star, type locality of S. r. dissors; red star, type locality of S. r. caquetensis; red star with white spot, type locality of S. r. confinis; blue star, type locality of S. r. amazonica; blue star with a white spot, type locality of S. r. tertia; orange star, type locality of S. r. rutilans; yellow star, type locality of S. r. omissa.

Figure 4. Plumage distribution and geographic variation in the Synallaxis rutilans group. Dark grey circles, specimens with grey-patterned plumage; pale grey circles, specimens with olive-patterned plumage; black circles, specimens with rufous-patterned plumage. Concerning intermediate individuals, any specimen with rufous present on the upperparts was classified in the ‘specimens with rufous-patterned plumage’ group. *Illustrations of birds with the typical plumage of: S. caquetensis (on the left); S. dissors (centre above); S. omissa (right). Area of endemism (AE) and distribution of species of the Synallaxis rutilans group: purple, Guiana EA, S. dissors; red, Napo EA, S. caquetensis; orange, Xingu EA, S. rutilans; yellow, Belém EA, S. omissa; and green, Inambari EA, blue, Rondônia EA and turquoise, Tapajós EA, S. amazonica. *Illustrations from del Hoyo J, Elliott A, Sargatal J, Christie DA, de Juana E, eds. 2017. Handbook of the birds of the world alive. Barcelona: Lynx Edicions (retrieved on 10.11.2017 from http://www.hbw.com).