Star-throated Antwren Rhopias gularis Scientific name definitions

Recent genetic data, which simultaneously confirmed the distinction of those antwrens now placed in the genus Epinecrophylla, found that the Star-throated Antwren might also be better placed in a genus other than Myrmotherula. Given its stippled throat pattern, this species might be assumed to belong with the Amazonian and trans-Andean species now placed in Epinecrophylla, but the Star-throated Antwren constructs a quite different nest, and its foraging behavior also appears to separate the species. The Star-throated Antwren is endemic to southeastern Brazil, where it remains close to the ground in evergreen forest, from sea level to mid elevations, and is often found near streams and in ravines. It occasionally joins mixed-species flocks in the understory, but is more usually found alone or in pairs.

8·5–9·5 cm; 10–12 g. Male has forehead greyish, crown, upperparts , remiges and tail rufous-brown; hidden white interscapular patch; wing-coverts blackish-brown, greater and median coverts dotted pale cinnamon, bend of wing edged white; throat black, spotted white, breast and belly grey, flanks and undertail-coverts pale rufous-brown. Female  differs from male in having forehead buffy, white throat spots larger, no interscapular patch.

SE Brazil in coastal region from SE Bahia S to Santa Catarina and NE Rio Grande do Sul (2 Bencke, G.A., Chiarani, E., Bianco, A., Hasenack, W. and Medaglia, M.F. (2018). Recent records of the Star-throated Antwren, Rhopias gularis (Spix, 1825) (Aves, Thamnophilidae), in Rio Grande do Sul, southern Brazil. Check List. 14(6): 1099–1104. Close ), extending inland in S to W Paraná.

Little published. Feeds on a variety of small insects, including crickets (Gryllidae), grasshoppers (Acrididae), hemipterans, and lepidopteran larvae; also spiders. Forages in pairs or individually, mostly 0–5 m above ground, rarely to 8 m, moving actively but not usually hurriedly, and routinely flicking both wings. In intraspecific displays, males face each other c. 15 cm apart, with wings splayed to show white spots. Most commonly forages within a few centimetres of ground, clinging laterally to slender vertical stems, ferns, palmettos and saplings, alternating between upward-reaching perch-gleans and short jumping sallies to undersides of leaves; also sally-pounces to snatch prey from surface of leaf litter, and hops on fallen logs and surface debris. In addition, regularly works through fallen branches and through shaded understorey trees, where it scans both live and dead leaves; often (but not habitually) pauses to probe the latter, typically for 1–4 seconds, occasionally longer. When foraging more than 1 m above ground, most often hitches up through vine tangles or along central portions of trees, avoiding terminal branches, and often probing in tufts of moss on trunks and larger branches. Also gleans from bare-stem, branch and vine surfaces. Generally alone, but sometimes in company of mixed-species understorey flocks at lowland elevations, where often with Red-crowned Ant-tanagers (Habia rubica), foliage-gleaners (Furnariidae) and other thamnophilids. One published record of a pair following army ants (Labidus praedator) for one hour through dense growth near a treefall.

Loudsong a short (e.g. eight notes, 2·4 seconds), evenly paced, countable series of harsh downslurred notes, intensity increasing initially, pitch decreasing terminally. Other vocalizations include brief, harsh notes; a short, flat rattle-like call (individual elements not distinct), sometimes in series of 3–4; and a short (e.g. 0·5 seconds) rattle (individual notes distinct).

Three previously unpublished nests, found in Nov in São Paulo, Paraná and Santa Catarina, were sited 0·6–1·0 m off the ground in shrubs hanging over or adjacent to watercourses that flowed through tall (c. 20 m high) forest. Nests were cup-shaped, and constructed amongst several thin branches or placed in a branch fork; nests were c. 7 cm in diameter (one widening to 9·5 in one direction) and 6–8 cm high, constructed of roots and Marasmius fungal strands; no dead leaves were hung from nests but fresh green moss placed around one. Both adults carried food to the nest. Eggs have been described as white, with very fine, barely needlestitch-sized brown spots that condense into a wreath on blunt end. At Carlos Botelho State Park, São Paulo, 12 nests found between late Oct 2013 and early Jan 2014, and another 15 in the subsequent breeding season; all were pensile cups, attached by their rims to slender horizontal branches of saplings or shrubs, usually in the angle of a fork, 34–70 cm high; the outer nest layer was of fine dark rootlets, black fungal fibres and pieces of dried fern leaves, and the inner lining was of black fungal fibres; all clutches were two; eggs  short-oval shaped, mean c. 19 mm × 14·5 mm (n = 18), white with reddish and dark brown spots and blotches of irregular shape and size, incubated c. 17 days; hatchlings  have pinkish skin, devoid of down, with dark bill, orange mouth interior and yellow commissures, and fledge at c. 11 days; 57% of nests were successful (3 Perrella, D.F., Biagolini-Júnior, C.H., Ribeiro-Silva, L., Zima, P.V.Q., Galetti, P.M. Jr. and Francisco, M.R. (2015). Nest, eggs, and nestlings of the Atlantic Forest endemic Star-throated Antwren (Rhopias gularis). Wilson J. Orn.. 127(2): 319–323. Close , 4 Perrella, D.F., Biagolini Junior, C.H., Ribeiro-Silva, L., Zima, P.V.Q. and Francisco, M.R. (2017). Reproduction of the Atlantic Forest endemic star-throated antwren, Rhopias gularis (Aves: Thamnophilidae). Braz. J. Biol.. http://dx.doi.org/10.1590/1519-6984.14715. Close ).

Not globally threatened (Least Concern). Restricted-range species: present in Atlantic Forest Lowlands EBA. Generally uncommon. No recent records from W Paraná and N Rio Grande do Sul, where recorded historically. Although not currently threatened, its populations should be monitored for signs of decline. Less than 20% of original forest in the region remains; although this species occurs in a number of well-protected parks and reserves, e.g. Itatiaia, Serra dos Órgãos and Serra da Bocaína National Parks, and Serra do Mar and Desengano State Parks, other reserves lack the manpower and infrastructure for adequate protection. The enforced protection of all existing parks and reserves should ensure the continued viability of this species. Even so, the deforestation, colonization, agricultural expansion and urbanization that inevitably follow an expanding human population in this already most densely populated region of Brazil will present continuing threats to the integrity of the reserves on which this and many other endemic species depend.