Caatinga Antwren Radinopsyche sellowi Scientific name definitions

The Caatinga Antwren has only recently been recognized, primarily on the basis of its vocalizations, as a separate species from the Bahia Antwren (Herpsilochmus pileatus); they were formerly united under the name Pileated Antwren. It is endemic to caatinga scrub and the borders of deciduous woodland in northeast Brazil, south as far as northern Minas Gerais, where it comes into contact with the similarly-plumaged but larger and longer-tailed Black-capped Antwren (Herpsilochmus atricapillus). The present species is less arboreal and generally forages closer to the ground than the Black-capped Antwren, which mainly tends to remain in the canopy. The species’ scientific name pays homage to an early German botanist and collector of birds who travelled extensively in eastern Brazil, Frederich Sellow.

10.5–11.5 cm; 6.5–8 g (1 Olmos, F., and C. Albano (2012). As aves da região do Parque Nacional Serra da Capivara (Piauí, Brasil). Revista Brasileira de Ornitologia 20(3):173–187. Close ). Male has black crown and nape, white lores, long white to pale gray supercilium, short blackish postocular streak; upperparts gray, white interscapular patch usually with some black feather tips, blackish outer scapulars edged white; wings black, remiges edged white, coverts tipped white; graduated tail black, large white tips, outer feathers edged white; underparts white, tinged gray on breast, sides, flanks and crissum; underwing-coverts white. Distinguished from the very similar Black-capped Antwren (Herpsilochmus atricapillus) by shorter postocular streak, no black loral spot, shorter narrower bill, other measurements. Female differs from male in having forehead and forecrown feathers edged dull buff (dappled effect), indistinct postocular streak, olive tinge above, supercilium and underparts tinged pale buff, underwing-coverts faintly tinged yellow.

Long known as part of Herpsilochmus pileatus, but a study showing a population of southeastern Bahia to be a distinct species also revealed that this name is instead applicable to the newly discovered form (Bahia Antwren (Herpsilochmus pileatus)). Morphological and vocal details revealed that the present species differs clearly from the Bahia Antwren and its close relatives, to the extent that it might merit separation in its own genus (2 Whitney, B. M., J. F. Pacheco, D. R. C. Buzzetti, and R. Parrini (2000). Systematic revision and biogeography of the Herpsilochmus pileatus complex, with description of a new species from northeastern Brazil. Auk 117(4):869–891. Close ). A molecular phylogeny of antwrens confirmed that Caatinga Antwren does not belong within Herpsilochmus, but is instead sister to White-bearded Antshrike (Biatas nigropectus); thus it is placed in the new monotypic genus Radinopsyche (3 Bravo, G. A., B. M. Whitney, R. Belmonte-Lopes, M. R. Bornschein, N. Aristizábal, R. Beco, J. Battilana, L. N. Naka, A. Aleixo, M. R. Pie, L. F. Silveira, E. P. Derryberry, and R. T. Brumfield (2021). Phylogenomic analyses reveal non-monophyly of the antbird genera Herpsilochmus and Sakesphorus (Thamnophilidae), with description of a new genus for Herpsilochmus sellowi. Ornithology 138(3):ukab025. Close ).

Northern-central & eastern Brazil (southern Pará (2 Whitney, B. M., J. F. Pacheco, D. R. C. Buzzetti, and R. Parrini (2000). Systematic revision and biogeography of the Herpsilochmus pileatus complex, with description of a new species from northeastern Brazil. Auk 117(4):869–891. Close , 4 Pacheco, J. F., and F. Olmos (2005). Birds of a latitudinal transect in the Tapajós-Xingu Interfluvium, eastern Brazilian Amazonia. Ararajuba 13(1): 29–46. Close ), Maranhão east to Rio Grande do Norte and south to Bahia and extreme northern Minas Gerais).

Middle and upper strata of caatinga woodland and scrub, mata-de-cipó vine forest, caatinga-cerrado ecotone; also restinga woodland in coastal Rio Grande do Norte; mostly at 300–900 m, but locally to 1,100 m, and to near sea-level in the north. Most numerous in semi-deciduous caatinga woodland and mata-de-cipó forest (semi-deciduous forest rich in vines and terrestrial bromeliads at 700–1,000 m Bahia); usually absent from more humid evergreen forest and arid lowland caatinga scrub.

Little published. Feeds on variety of insects, including orthopterans, particularly katydids (Tettigoniidae), also lepidopteran larvae, hemipterans and coleopterans; probably also on spiders. Stomach contents of two specimens from Pará contained orthopterans, beetles (Curculionidae) and hemipterans. Closely associated pair-members, individuals, or family groups forage mostly from 1.5 m (at shrubby borders and in dense mata-de-cipó woodland) to 12 m above ground. Alone, or with mixed-species flocks; often occurs in same flocks as syntopic Black-capped Antwren (Herpsilochmus atricapillus), then more often forages in open branches beneath canopy and in low, shrubby vegetation than latter; more locally, with Pectoral Antwren (Herpsilochmus pectoralis) or Rufous-margined Antwren (Herpsilochmus rufimarginatus). Active but methodical forager, progressing steadily by short hops, separated by frequent pauses of 1–2 seconds to scan foliage, stems and branches. Typical foraging posture is horizontal, with the tail held slightly above plane of body and frequently lowered and then flicked upwards in shallow arc; both wings also regularly flicked, but not in exaggerated fashion. Prey usually perch-gleaned from live leaves or stems by reaching up, out or down and picking, or by short horizontal lunges; less frequently hangs head down to glean prey from tops of leaves, or makes short (15–30 cm) vertical sallies to underside of overhanging vegetation; seldom investigates dead leaves. Prey capture often accompanied by audible snap of the mandibles; most smaller items are immediately gulped; larger prey, such as many katydids, routinely beaten several times against a branch before being swallowed. Not known to follow army ants.

Loudsong a rapid series of similar notes (e.g., 40 notes, 2.8 seconds) mostly repeated at same pitch and pace, but rising and falling in pitch and amplitude at beginning and end. Rattle-like call a short (e.g., six notes) repetition of wiip notes; rattle short (e.g., 1 second), rising in pitch, usually introduced by slightly longer downslurred note.

Almost nothing known. One record of nearly fledged young in February.

Not globally threatened (Least Concern). Previously considered Near Threatened. Uncommon to fairly common throughout most of range. Known to occur in three protected areas: Chapada do Araripe National Forest (Ceará), Chapada Diamantina National Park (Bahia) and Cavernas do Peruaçu National Park (Minas Gerais). Most of its range, however, is without formal protection. Considered to be of medium sensitivity to human disturbance. Main problem is habitat loss and degradation. The dry forest, caatinga scrub and mata-de-cipó woodland favoured by this species are being rapidly cleared for cattle pastures and coffee plantations; even where not being cleared, they are being heavily exploited by local people for firewood and fence-post production, with grazing by cattle and goats preventing regeneration of most of the woody plants. The mata-de-cipó woodlands of Bahia, despite harboring a high proportion of endemic and threatened species, remain unprotected; establishment of one or more reserves, preferably in Jequié-Boa Nova region, is a high priority. Until such reserves are set up, the future of this and other dry-forest endemics of the region will remain in question.