Cercomacra cinerascens

Cercomacra cinerascens (Sclater, 1857) Formicivora cinerascens (partim) Sclater, 1857: 131. Formicivora caerulescens [non Myrmothera caerulescens Vieillot, 1817, non Formicivora caerulescens Ménétriès, 1835] – Sclater (1854: 112). Cercomacra cinerascens (partim) – Sclater (1858: 245). Cercomacra napensis Sclater, 1868: 572. Cercomacra sclateri (partim) [non Cercomacra sclateri Hellmayr, 1905] – Hellmayr (1905: 288). Cercomacra sclateri [non Cercomacra sclateri Hellmayr, 1905] – Chapman (1917: 380). Cercomacra cinerascens immaculata Chubb, 1918: 84. Cercomacra cinerascens cinerascens – Zimmer (1932: 20). Lectotype. BMHN 55.12.17.72. Male. Type locality. Margins of the Napo River, Ecuador. Diagnosis. The taxon is diagnosable by its light gray males (gray N / 5) and olive yellow females (olive yellow 2.5 Y 6 / 8). They lack (or they are reduced) wide fimbriae and white tail tips; the interscapular patch is very reduced or missing, and the under-wing coverts are the same color as the belly (gray N / 5) (Fig. S 6). These features are combined with a loudsong which is a disyllabic series of repeated and intercalated clear and raspy notes, similar to that of C. iterata stat. nov. Distribution. This species of northern Amazonia is confined to the south by the Pastaza-Marañon-Solimões-Amazon Rivers and to the north by the boundary of the Amazon rainforest, including the Orinoco River in Venezuela. It appears to be absent from the Colombian Llanos. Remarks. It differs from the southern counterparts by the lighter overall coloration of females and males, absence of white fimbriae, tail tips and interscapular patch, in addition to having significant, although overlapping, shorter tail length (compared to iterata), tail tip (compared to the four southern species) and wing chord (compared to the four southern species, except for iterata) in females. Males cinerascens are larger than the other southern species in almost all measurements (Table SS 4). Most vocal features differed significantly (with overlap) between cinerascens and the southern species, except for iterata (Table S 7). Some females show gray on the rump, which seems to be a preparation artifact. We synonymized C. c. immaculata Chubb, 1918 with the nominotypical form because they are indistinguishable in both plumage and vocalizations. Additionally, the syntypes of C. c. immaculata (BNHM 1922.3. 5.2163, 1922.3. 5.2164, 1922.3. 5.2165, 1922.3. 5.2166) display features the author identified as diagnostic, such as the absence of the interscapular patch (Chubb 1918: 84). This feature is seen in all male specimens from Óbidos in the CMNH collection, for example. Young males with female-like plumage have longer tail with smaller, paler tips; their shape is also thinner and more pointed. The following four species unquestionably belong to the southern populations because they have darker gray males (very dark gray N / 3) and darker yellow females (olive 5 Y 4 / 4). Both sexes exhibit prominent white (white N 8 /) fimbriae, an interscapular patch, and wide (> 3.5 mm) tail tips. No consistent differences were found in the southern female plumage, although some individuals of C. sclateri displayed a gray crissum (very dark gray N / 3), contrasting with the yellowish back of certain females of C. iterata stat. nov. However, they are clearly different in their vocalizations.