Variable Antshrike

thamnophilus caerulescens

Thamnophilidae · Antbirds, Antwrens

Disc 2 · 2001 listed
Disc 3 · 2006 listed
Disc 1 · 2011 listed

The account

Description

14 cm. The form in southeast Brazil is gray above.

Male has a black cap and a gray back with black feathers and a concealed white dorsal patch. Rump and tail black. Wings black with three rows of spotted white bars. Tail and rump feathers have white tips. Below somewhat lighter. Belly tawny.

In the female the crown is rufous instead of blackish, the mantle is olive-grayish, the wings and tail are grayish-black instead of black and the belly is more tawny. Otherwise like male.

The disc records this picture against the bird without a caption. Disc 3 · 2006

Where it was recorded

The discs' own checklists select Variable Antshrike at 24 localities.

Historical checklist localities on the disc's own area map — the red dots the original program drew, placed by its recovered projection. Not a range map: it shows the places whose checklists record the bird, nothing more. 1 recorded locality lies beyond the map's edge and is listed below instead.1 has no usable coordinate and is listed below unplotted.

Barreiro Rico BRSB
Boraceia BOSB
Campos do Jordão CASB
Fazenda Campininha FZSB
Fazenda Intervales FASB
Fazenda Paraiso PASB
Ilha do Cardoso ILSB
Itirapina ITSB
Jureia-Peruibe JUSB position not recoverable
Morro do Diabo MOSB outside the map
Nucleo Sta. Virginia NUSP
Parati PARB
Pariquera-Abaixo PESB
PE Carlos Botelho PCSB
PE Jacupiranga PJSB
Reserva Ecológica Guapiacú RERB
Santa Barbara do Rio Pardo SNSB
Serra Bocaina SESB
Serra da Cantareira SRSB
Serra dos Orgãos SRRB
Serra dos Tucanos SDTC
Serras de Japi e Ermida SDSB
Ubatuba UBSB
Vassununga VASB

How the map was made

The original program computed each red dot at display time from the locality's coordinates, using its map library and one of five base maps drawn for the screen widths of the day. That library's projection — an oblique rotation of the sphere about the map's own centre, 23.7°S 47.4°W — was read from the program and checked against the graticule the same program drew into the base maps: it reproduces every grid intersection to within about a pixel. The dots here use that projection on the 1280-pixel base map, with the coordinates the discs record. Nothing was placed by hand, no modern map data was used, and a place whose coordinate is incomplete, out of range or beyond the map's edge is listed rather than guessed.

The discs carried location maps only; none shows a distribution or range.

Voice

A low and evenly pitched 'tja tja tja tja tja tja tja', about 5 syllables per second. Call a single 'caw-caw-caw....', or a 'gwew-o' or 'ga-ee' (³⁰).

Behavior

In dense undergrowth, but sometimes confiding and easy to see.

Habitat and status

In undergrowth of dense primary and secondary woodland and forest borders, bamboo thickets (but not particularly associated with bamboo).

Distribution

Throughout the area, a relatively common bird, typical of the higher elevations. More inside of true forest than Thamnophilus ruficapillus. To about 2000 meters.

Taxonomy notes

The southeast Brazilian forms are caerulescens and gilvigaster (in the south of São Paulo).

Decoded from the disc's own bytes. Each part is shown under the heading the disc files it under, and the wording, spelling and punctuation are the author's.

Vocalizations

Song. Iguape 11/7/95. Cloudy, 25°C. Secondary forest, scrub.
Song. Serra das Rosas near Franca, 11/13/98. Sunny, 27°C. Secondary forest. With Dysithamnus mentalis, Basileuterus culicivorus.
Song. 10/23/99, Serra Mantqueira, Agulhas Negras Road. Clear, cool, 20°C, in the morning fog. Forest. With Tijuca atra, Phylloscartes difficilis.
Call. 10/23/99, Serra da Mantiqueira, Agulhas Negras road. Clear, cool, 16°C. Montane forest. With Tijuca atra, Chamaeza ruficauda, Grallaria varia, Basileuterus leucoblepharus.
Atypical song, possibly belonging to this species, Oct. 1993, Iguape, São Paulo. cloudy. Secondary forest.
Songs. First part-Fazenda Intervales, 11/10/95. Sunny, 25°C. Open scrub. Second part-Espirito Santo. Recording by Juan Mazar Barnett

Recording files on the disc

4181.mp3 Song. Iguape 11/7/95. Cloudy, 25°C. Secondary forest, scrub.
228.mp3 Song. Serra das Rosas near Franca, 11/13/98. Sunny, 27°C. Secondary forest. With Dysithamnus mentalis, Basileuterus culicivorus.
6939.wav Song. 10/23/99, Serra Mantqueira, Agulhas Negras Road. Clear, cool, 20°C, in the morning fog. Forest. With Tijuca atra, Phylloscartes difficilis.
6544.wav Call. 10/23/99, Serra da Mantiqueira, Agulhas Negras road. Clear, cool, 16°C. Montane forest. With Tijuca atra, Chamaeza ruficauda, Grallaria varia, Basileuterus leucoblepharus.
8225.mp3 Atypical song, possibly belonging to this species, Oct. 1993, Iguape, São Paulo. cloudy. Secondary forest.
7365.mp3 Songs. First part-Fazenda Intervales, 11/10/95. Sunny, 25°C. Open scrub. Second part-Espirito Santo. Recording by Juan Mazar Barnett

Across the three discs

The work was published on three discs — Disc 2 in 2001, Disc 3 in 2006 and Disc 1 in 2011. Where they differ, that is a difference between historical releases, and it is never merged away. The 2011 disc is not treated as correcting the earlier ones.

Which discs list this bird

Disc 2 · 2001 — in this disc's bird list
Disc 3 · 2006 — in this disc's bird list
Disc 1 · 2011 — in this disc's bird list

How that was established

Disc 2 · 2001: aux_nonzero;local_checklist_byte45_flag_1
Disc 3 · 2006: aux_nonzero;local_checklist_byte45_flag_1
Disc 1 · 2011: aux_nonzero;local_checklist_byte45_flag_1

The disc's own record fields that place the bird on its list: a non-empty entry in the species table, and the byte that marks it as selected on a local checklist.

The account in the Disc 1 · 2011 revision

The 2011 Disc 1 revision carries this account text unchanged from the Disc 3 release.

The work's own taxonomy

The discs carried three parallel name schemes. All three are shown as recovered; none is a modern taxonomy and none has been updated.

Scheme	Scientific name	English name	Family
WORLD	thamnophilus caerulescens	Variable Antshrike	Thamnophilidae
CLEMENTS	thamnophilus caerulescens	Variable Antshrike	Thamnophilidae
AOU_HM	thamnophilus caerulescens	Variable Antshrike	Thamnophilidae

Source details

Identifier on this site: seb_species_0116
Account identifier: seb_account_0116
Account number on the disc: 116
Source edition: CD03 / 2006 package
Original taxonomy scheme: WORLD
Structure status: heuristic; decoded_account_text and segment JSON remain authoritative