Myrmotherula cinereiventris Sclater and Salvin, 1868

Isler, Morton L., Chesser, R. Terry, Stryjewski, Katherine Faust & Whitney, Bret M., 2025, Systematics of three pan-Amazonian antwren lineages (Aves: Passeriformes: Thamnophilidae: Myrmotherula and Isleria), Zootaxa 5722 (1), pp. 45-78 : 62

Myrmotherula cinereiventris Sclater and Salvin, 1868 , subspecies elevated to species

Northern Gray Antwren

Includes the study populations designated cinereiventris , pallida- E, and pallida- W in the analysis.

Diagnosis. Myrmotherula cinereiventris is distinguished from M. menetriesii s.s. and M. omissa by vocalizations and plumage. The structure of notes in M. cinereiventris Songs differs from that of M. menetriesii Songs ( Fig. 6), and the note pattern in M. cinereiventris Long Calls differs from those in M. menetriesii and M. omissa in the sequence of types of notes ( Fig. 7). The male differs from male M. menetriesii in having a gray rather than black throat and upper breast.

Description of female plumage. Females of the nominate population have upperparts between Olive Gray and Olive (5Y4/2–5Y4/3), wings and tail with pale feather edgings colored like underparts; and underparts Yellow Ochre (10YR7/6), paler on chin and sides of head.

Distribution. Bounded on the north in Colombia by the Rio Inírida, extending north to Meta along Andean foothills, and in Venezuela by the Rio Orinoco; on the northeast by the Atlantic Ocean in the Guianas; on the east by the Atlantic Ocean in Brazil; on the south by the Rio Amazonas and Rio Marañón; and on the west by Andean foothills.

Remarks. Coloration of male of M. c. pallida is similar to nominate but paler, and female is distinctly grayer above and darker below compared to nominate. Specific status for Myrmotherula cinereiventris is supported by distinctions in vocalizations (Song and Long Call differ from those of both M. menetriesii s.s. and M. omissa ) and in plumage (female coloration and the absence of the male breast patch of M. menetriesii s.s). Species status is reinforced by mtDNA genetic distances of ~5.0% among the three species that formerly constituted M. menetriesii sensu lato.