Myrmotherula paraensis Todd, 1920

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 : 55

Myrmotherula paraensis Todd, 1920 , subspecies elevated to species

Eastern Long-winged Antwren

Includes the study populations designated ochrogyna (both subclades) and paraensis in the analysis.

Diagnosis. Myrmotherula paraensis is distinguished from M. longipennis and M. garbei by vocalizations and female plumage. The shape (structure) of notes in Songs of M. paraensis differs from note shapes in both M. longipennis and M. garbei Songs ( Fig. 2). The pace of M. paraensis Songs is faster than the pace of Songs of M. longipennis and M. garbei . Notes in M. paraensis Songs rise in frequency, whereas the frequency of notes in M. longipennis Songs declines. Note shapes in the Series Call of M. paraensis differ from those of M. longipennis , and note shape of the Multi-note Call of M. paraensis differs from that of M. garbei ( Fig. 3). Diagnosable plumage differences are limited to females. Although females of two of the three subspecies of M. paraensis have grayish upperparts, they differ diagnostically from the very dark gray upperparts of M. garbei . Females of two of the M. paraensis subspecies have whitish bellies tinged with buff and differ diagnostically from the white-bellied M. longipennis .

Description of female plumage. Myrmotherula paraensis encompasses three subspecies that differ substantially in coloration. Upperparts of M. p. paraensis are dark grayish olive brown to olive gray (2.5Y4/2–4/3 to 5Y4/2–4/3); those of transitiva are olive brown or yellowish brown (2.5Y4/4–5/6 or 10YR5/6); and those of ochrogyna are reddish yellow brown (7.5YR4/6–4/4). Wings and tails of p. paraensis and transitiva are very dark grayish olive brown (2.5Y3/2); those of ochrogyna are reddish yellow brown (7.5YR4/3). Wing edgings of p. paraensis are light yellowish olive-brown (2.5Y6/4); those of transitiva are pale yellowish olive brown (2.5Y7/4); and those of ochrogyna are buffy brown (10YR7/4). Underparts of the three subspecies also differ as follows. The throat, breast and belly of p. paraensis are pale olive yellow (2.5Y7/4–7/6), and the flanks and crissum are light olive brown (2.5Y6/4–5/4). The throat and belly of transitiva are white tinged pale olive yellow (2.5Y7/6), the breast is pale yellow olive (2.5Y7/4–7/6), and the crissum and flanks are light olive brown (2,5Y6/4–5/4). The throat, belly, and crissum of ochrogyna are white tinged brownish yellow (10YR6/8), and the breast (creating a breast band) and flanks are brownish yellow ochre (10YR7/6–6/8).

Distribution. Brazil south of the Rio Amazonas; east of the Rio Madeira, west of the Rio Pindaré, Maranhão, and west and north of southern Amazonian forest limits; southern Isla Marajó.

Remarks. Hellmayr (1929) described M. l. transitiva and compared plumages of paraensis , ochrogyna, and transitiva. He found coloration differences to be limited to females (e.g., in depth of color, brightness and rufescence of upperparts, and warmth and depth of buffy underparts), with transitiva being nearer paraensis . Our results are consistent with Hellmayr’s observation that ochrogyna and paraensis differ more in coloration than do transitiva and paraensis . Consistency of vocalizations among the three populations indicates that ochrogyna and transitiva are best considered subspecies of paraensis . Given the lack of known significant vocal differences, we maintain both transitiva and ochrogyna as subspecies pending additional field data from the region.