Unicolored Antwren

myrmotherula unicolor

Thamnophilidae · Antbirds, Antwrens

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

The account

Description

9 cm. Male is slate-gray with a darker throat patch. Wings gray without wing bars.

Female is rufous-brown above and more buff underneath.

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

Where it was recorded

The discs' own checklists select Unicolored Antwren at 12 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 has no usable coordinate and is listed below unplotted.

Boraceia BOSB
Ilha do Cardoso ILSB
Jureia-Peruibe JUSB position not recoverable
Marica MRRB
Parati PARB
PE Jacupiranga PJSB
Reserva Ecológica Guapiacú RERB
Rio de Janeiro RIRB
Serra dos Orgãos SRRB
Serra dos Tucanos SDTC
Sete Barras STSB
Ubatuba UBSB

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

Following ⁵⁸: 1) A descending 'whee', the song is an "evenly paced series of two to ten of these lengthened, descending syllables". A sequence of notes, possibly a song, can be heard on track #1 at the end.

2) A 'djeer djeer' which can be heard at the beginning of track # 1.

3) A series of raspy syllables the first of which is different from the rest, maybe a scold or mobbing vocalization.

4) The most common contact vocalization is a 'kleek' or 'wheet' as heard on track # 2 and track # 3.

Behavior

In pairs, family groups or in mixed flocks within 4-11 meters from the ground in tall forest (⁵⁸). I have also observed groups of this species at Jureia at 2-3 meters above the ground. Moves through vegetation in short flights collecting prey with gleans and reaches. Selects preferentially dead leaf substrates (⁵⁸).

Habitat and status

A relatively common endemic antwren of the Atlantic Forest. In the interior of tall primary and old secondary rain forest and restinga. This species seems to be more adaptable to secondary forest and brush than Myrmotherula minor.

Distribution

Throughout the area, always close to the coast from Rio de Janeiro to Ilha do Cardoso. Not inland. Mostly below 200 meters.

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

Calls. Picinguaba, east of Ubatuba, 11/21/98. Cloudy, light rain, 20°C. Secondary forest.
Calls, 'jee see see see'. Jureia-Peruibe, 10/12/99. Cloudy, 22°C. Primary forest. With Attila rufus, Herpsilochmus rufimarginatus, Myiodynastes maculatus, Mionectes rufiventris.
Calls. Cornell Cat#19293. Osorio, Fazenda do Pontal, Rio Grande do Sul, 1/22/76. With Leptotila verreauxi. Recording by W. Belton.

Recording files on the disc

4295.wav Calls. Picinguaba, east of Ubatuba, 11/21/98. Cloudy, light rain, 20°C. Secondary forest.
6856.wav Calls, 'jee see see see'. Jureia-Peruibe, 10/12/99. Cloudy, 22°C. Primary forest. With Attila rufus, Herpsilochmus rufimarginatus, Myiodynastes maculatus, Mionectes rufiventris.
13864.wav Calls. Cornell Cat#19293. Osorio, Fazenda do Pontal, Rio Grande do Sul, 1/22/76. With Leptotila verreauxi. Recording by W. Belton.

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	myrmotherula unicolor	Unicolored Antwren	Thamnophilidae
CLEMENTS	myrmotherula unicolor	Unicolored Antwren	Thamnophilidae
AOU_HM	myrmotherula unicolor	Unicolored Antwren	Thamnophilidae

Source details

Identifier on this site: seb_species_0128
Account identifier: seb_account_0128
Account number on the disc: 128
Source edition: CD03 / 2006 package
Original taxonomy scheme: WORLD
Structure status: heuristic; decoded_account_text and segment JSON remain authoritative