Family Typical Antbirds (Thamnophilidae)

Least Concern

Variable Antshrike (Thamnophilus caerulescens)


Taxonomy

French: Batara bleuâtre German: Wechselameisenwürger Spanish: Batará variable
Taxonomy:

Thamnophilus cærulescens

Vieillot

, 1816,

Paraguay

.

Closest to T. unicolor, these two species, with T. aethiops and T. aroyae, forming a well-supported clade#R; previously considered close to T. amazonicus, but such a relationship now appears unfounded. Although complex plumage variation and unusual geographical distribution suggest present species may merit taxonomic splitting, an innovative study of vocal characters#R found that variation in pace (notes per second) of male loudsongs was clinal and, moreover, that geographical pattern of clines accorded with genetic variation found in molecular study#R. Other proposed races seem indistinguishable or plumage differences appear clinal: thus, subandinus (N Peru) synonymized with melanochrous; connectens (EC Bolivia) with dinellii; albonotatus (EC Brazil) with nominate; and pernambucensis (NE Brazil) with cearensis. Further study required to examine if there is any parapatry without intergradation among accepted races. Eight subspecies recognized.

Subspecies and Distribution
  • T. c. melanochrous P. L. Sclater & Salvin, 1876 – E slope of Andes in Peru (from Amazonas S of R Marañón S to N Puno).
  • T. c. aspersiventer d’Orbigny & Lafresnaye, 1837 – SE Peru (SE Puno) and WC Bolivia (N slope in La Paz, Cochabamba and Santa Cruz).
  • T. c. dinellii Berlepsch, 1906 – EC & S Bolivia on S & E Andean slopes (Santa Cruz S to Tarija), and NW Argentina (E slope from Jujuy S to La Rioja and, at lower elevations, E to Formosa and S to N Córdoba and Santa Fe).
  • T. c. paraguayensis Hellmayr, 1904 – SE Bolivia (lowlands of Santa Cruz), NW & NC Paraguay (W of R Paraguay and, to E, in Concepción, Amambay and San Pedro) and S Brazil (Mato Grosso do Sul).
  • T. c. gilvigaster Pelzeln, 1868 – NE Argentina (E of R Paraná except Misiones), extreme SE Brazil (E Paraná and SE São Paulo S to Rio Grande do Sul) and Uruguay.
  • T. c. caerulescens Vieillot, 1816 – SE Paraguay (E of R Paraguay except Concepción, Amambay and San Pedro), extreme N Argentina (Misiones), and N part of SE Brazil (Minas Gerais and SE Bahia S to W Paraná, W & NE São Paulo and Rio de Janeiro).
  • T. c. ochraceiventer E. Snethlage, 1928 – EC Brazil (S Tocantins, Goiás, Distrito Federal, SC Bahia).
  • T. c. cearensis (Cory, 1919) – NE Brazil (Ceará, Pernambuco, Alagoas).
  • Descriptive notes

    14–16 cm; 15–24 g. Male nominate race has forehead and crown black, side of head grey, upperparts dark grey, mixed with black on lower back, white interscapular... read more

    Voice

    Loudsong a simple countable series of usually 6–7 plaintive, evenly spaced whistles of same... read more

    Habitat

    Understorey and mid-storey of evergreen forest, second-growth woodland, and patches of thickets and... read more

    Food and feeding

    Little published. Feeds primarily on insects, including moths and larval lepidopterans, katydids (Tettigoniidae), grasshoppers (Acrididae... read more

    Breeding

    Oct–Feb in Brazil, Aug–Nov in Bolivia and Peru and Oct–Dec in Argentina. Nest of dinellii a well-woven cup,... read more

    Movements

    Ringing at a site in N Argentina (Salta) suggests some movement in S; presumed resident throughout... read more

    Status and conservation

    Not globally threatened. Fairly common over most of its extensive range, which includes a number of protected areas. This species’ adaptation to edge habitats, second-... read more

    Recommended citation

    Zimmer, K. & Isler, M.L. (2018). Variable Antshrike (Thamnophilus caerulescens). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from https://www.hbw.com/node/56688 on 20 November 2018).