White-necked Thrush

turdus albicollis

Turdidae · Thrushes

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

The account

Description

23 cm. A shy thrush of dense forest. Upper side chocolate brown. Throat with black stripes on white background. Below the striped throat a white crescent field. Chest and belly light gray. Flanks rufous. Bill mostly yellow with black ridge. Eye ring yellow.

Juvenile head and upper side brown, darker on wings and tail. Orange-buff central shaft streaks to feathers of face, crown, nape and neck. Larger streaks on mantle, back and rump. Scapulars broadly edged buffy. Median and greater coverts with pale orange buff spots. Throat whitish, spotted brown. Breast and flanks mottled brown and buff-orange. Belly and crissum whitish buff (¹⁴³).

Adult Disc 3 · 2006
Juvenile Disc 3 · 2006

Each plate is labelled with the disc's own caption.

Where it was recorded

The discs' own checklists select White-necked Thrush at 20 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.

Barreiro Rico BRSB
Boraceia BOSB
Campos do Jordão CASB
Fazenda Intervales FASB
Ilha do Cardoso ILSB
Itirapina ITSB
Jureia-Peruibe JUSB position not recoverable
Lencois LESB
Nucleo Sta. Virginia NUSP
Parati PARB
Pariquera-Abaixo PESB
PE Carlos Botelho PCSB
PE Jacupiranga PJSB
Reserva Ecológica Guapiacú RERB
Serra Bocaina SESB
Serra da Cantareira SRSB
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

Song is a monotonous sequence of phrases which are delivered in a slow sequence (vocalizations # 2 and 6), sings often in the heat of the day. Call is a slurred 'we' or 'wio', variations of which can be heard in vocalizations # 1, 3 and 4. Also a repeated 'jig-wig-wig' and a high frequency ' tsri' (¹⁴³).

Behavior

Forages inside of forests on the floor usually in dense undergrowth, shy. Visits fruiting trees. Occasionally forest edge.

Breeding

November to December.

Habitat and status

Not uncommon in areas with continuous forests.

Distribution

Found at e.g.PE Jacupiranga, Fazenda Intervales, Ubatuba, Parati, coastal forests near Peruibe and Iguape. Most common below 900 meters, but up to 1800 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

Call. Serra da Mantiqueira, 11/18/98. Sunny, 20°C. Forest.
Song. Serra da Mantiqueira, 11/18/98. Sunny, 20°C. High altitude scrub, 2500 meters. With Hylopezus nattereri.
Call. Jureia-Peruibe, 10/13/99. Sunny, 20°C. Forest. With Ramphocaenus melanurus.
Call. Jureia-Peruibe, 10/12/99. Sunny, 20°C. Primary forest.
Calls. Fazenda Intervales, 10/25/00. Cloudy, 20°C. Primary forest. With Procnias nudicollis, Trogon viridis, Dysithamnus stictothorax, Chaetura cinereiventris.
Song. Fazenda Intervales, 10/25/00. Cloudy, 20°C. Primary forest.

Recording files on the disc

10589.mp3 Call. Serra da Mantiqueira, 11/18/98. Sunny, 20°C. Forest.
93.mp3 Song. Serra da Mantiqueira, 11/18/98. Sunny, 20°C. High altitude scrub, 2500 meters. With Hylopezus nattereri.
10448.mp3 Call. Jureia-Peruibe, 10/13/99. Sunny, 20°C. Forest. With Ramphocaenus melanurus.
12627.mp3 Call. Jureia-Peruibe, 10/12/99. Sunny, 20°C. Primary forest.
8203.mp3 Calls. Fazenda Intervales, 10/25/00. Cloudy, 20°C. Primary forest. With Procnias nudicollis, Trogon viridis, Dysithamnus stictothorax, Chaetura cinereiventris.
4419.mp3 Song. Fazenda Intervales, 10/25/00. Cloudy, 20°C. Primary forest.

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

In the 2011 Disc 1 revision, part of this account was truncated at exactly 512 bytes (a 2011 mastering defect). The earlier releases preserve the complete text.

Truncated sections in the 2011 revision: description. The complete earlier text is shown beneath each truncated section.

Description Disc 1 · 2011

Disc 1 (2011) text ends here — truncated at exactly 512 bytes in the 2011 mastering (historical defect, kept as recovered).

Complete earlier text — Disc 3 · 2006 (133 bytes lost in 2011)

Shown for comparison from the Disc 3 · 2006; it does not repair or replace the Disc 1 · 2011 historical text above.

Voice Disc 1 · 2011

Behavior Disc 1 · 2011