Masked Water-Tyrant

fluvicola nengeta

Tyrannidae,Fluvicolinae · Fluvicoline Flycatchers

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

The account

Description

13 cm. A striking black and white ground flycatcher. White with black mask. Back light grayish. Wings and tail blackish-brown, the tail with a white tip.

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

Where it was recorded

The discs' own checklists select Masked Water-Tyrant 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.

Angra dos Reis ANRB
Fazenda Intervales FASB
Ilha São Sebastião SSSB
Jureia-Peruibe JUSB position not recoverable
Marica MRRB
Parati PARB
Reserva Ecológica Guapiacú RERB
Rio de Janeiro RIRB
Serra Bocaina SESB
Serra da Cantareira SRSB
Serra dos Orgãos SRRB
Serra dos Tucanos SDTC

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 is a 'tshilp' note similar to Passer domesticus. Song is a sequence of 'tektektek....' notes. Ridgely reports a 'zhweeoo' or 'zhreeo' (⁴⁴).

Behavior

Sallies from low perches or the ground to catch arthropod prey. Runs swiftly on the ground.

Habitat and status

Common near farms, fields, shores of lagoons, ponds and lakes and other open areas. Has clearly benefited by deforestation and is still expanding.

Distribution

Northern part of the area covered. Rio de Janeiro State and eastern São Paulo State. Below 800 meters (⁴⁴).

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, call. First part-Cornell Cat#09324. Santa Teresa, Espirito Santo, 10/16/1962. Recording by R. Ward. Second part - Cornell Cat#35711. 2 km northwest of Boa Nova, Bahia. Recording by T. A. Parker, III.

Recording files on the disc

475.wav Song, call. First part-Cornell Cat#09324. Santa Teresa, Espirito Santo, 10/16/1962. Recording by R. Ward. Second part - Cornell Cat#35711. 2 km northwest of Boa Nova, Bahia. Recording by T. A. Parker, III.

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	fluvicola nengeta	Masked Water-Tyrant	Tyrannidae,Fluvicolinae
CLEMENTS	fluvicola nengeta	Masked Water-Tyrant	Tyrannidae,Fluvicolinae
AOU_HM	fluvicola nengeta	Masked Water-Tyrant	Tyrannidae,Fluvicolinae

Source details

Identifier on this site: seb_species_0259
Account identifier: seb_account_0259
Account number on the disc: 259
Source edition: CD03 / 2006 package
Original taxonomy scheme: WORLD
Structure status: heuristic; decoded_account_text and segment JSON remain authoritative