Chestnut-capped Blackbird

agelaius ruficapillus

Icteridae,Icterinae · Troupials

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

The account

Description

18.5 cm. Adult male is mostly black, with the crown, throat and upper chest rusty brown.

The female is olive brown, with lighter underparts; dark spots on the mantle and streaks on the underparts. Throat buffy.

The young male has an intermediate plumage between the male and female, and black feather edgings below gives it a barred appearance.

The juvenile is like the female, but more buffy brown, strongly streaked below.

Adult male Disc 3 · 2006
Adult female Disc 3 · 2006
Juvenile Disc 3 · 2006
Immature male Disc 3 · 2006

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

Where it was recorded

The discs' own checklists select Chestnut-capped Blackbird at 6 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.

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

Call 'chick', 'tsiew', Song a fast warble with a broad low 'tcheeeee' at the end of the strophe (vocalization # 2). Song delivered while having tail spread and plumage fluffed out with vibrating wings. At breeding ground males attack any other bird.

Behavior

Gregarious, in larger or smaller flocks and family groups, breeds in swampy areas with cattails, high grass etc., raiding rice fields and other crops outside the breeding season.

Breeding

Colonial breeder, mostly inland.

Habitat and status

Not uncommon in marshes and reed beds, forages in high reeds, on the ground in adjacent drier pastures, fields, ditches. May be frequently found away from marshes in drier areas.

Distribution

Throughout. In Estado São Paulo widely and commonly distributed inland, e.g at Cubatao, Cantareira, Pontal near Franca, Tremembe (¹¹⁹). Up to 850 meters (¹³³)

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 and calls. Serra das Rosas São Paulo, near Franca, 11/7/98. Rain in the morning, then sunny, 27°C. Open woods, pastures.
Song of group. Serra da Canastra, 11/11/98. Cloudy, 25°C. Pond with cattail marsh. With Saltator similis.
Calls, song. Serra da Canastra, 11/11/98. Cloudy, 25°C. Pastures. With Columbina squammata, Pardirallus nigricans.

Recording files on the disc

11712.mp3 Song and calls. Serra das Rosas São Paulo, near Franca, 11/7/98. Rain in the morning, then sunny, 27°C. Open woods, pastures.
12640.mp3 Song of group. Serra da Canastra, 11/11/98. Cloudy, 25°C. Pond with cattail marsh. With Saltator similis.
6282.mp3 Calls, song. Serra da Canastra, 11/11/98. Cloudy, 25°C. Pastures. With Columbina squammata, Pardirallus nigricans.

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	agelaius ruficapillus	Chestnut-capped Blackbird	Icteridae,Icterinae
CLEMENTS	agelaius ruficapillus	Chestnut-capped Blackbird	Icteridae,Icterinae
AOU_HM	chrysomus ruficapillus	Chestnut-capped Blackbird	Icteridae,Icterinae

Source details

Identifier on this site: seb_species_0459
Account identifier: seb_account_0459
Account number on the disc: 459
Source edition: CD03 / 2006 package
Original taxonomy scheme: WORLD
Structure status: heuristic; decoded_account_text and segment JSON remain authoritative