Cock-tailed Tyrant
alectrurus tricolor
Tyrannidae,Fluvicolinae · Fluvicoline Flycatchers
- Disc 2 · 2001 listed
- Disc 3 · 2006 listed
- Disc 1 · 2011 listed
The account
Description
12 cm. A specialized grass tyrant with highly developed sexual dimorphism. In both sexes the bill is yellowish.
Male is black above with white cheeks, throat and belly. Rump gray. A black patch on the side of the breast. Secondaries with white patch.
The tail of the adult male may reach 19 cm and has the two center rectrices turned by 90° which then rise in a cocked position above the head level. The lateral rectrices form a steep plane on either side of the central tail feathers.
The female and young are buffy brown, mottled darker above with a prominent white superciliary stripe. The wings are darker, the primaries and tertiaries with white fringes, the secondaries rusty-brown. Below white with a buff wash and a brown patch on the sides of the breast. Tail is short and has a normal shape.
-
Male Disc 3 · 2006 -
Female Disc 3 · 2006
Each plate is labelled with the disc's own caption.
Where it was recorded
The discs' own checklists select Cock-tailed Tyrant at 2 localities.
- Itirapina ITSB
- Santa Barbara do Rio Pardo SNSB
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.
The account, continued
Voice
Usually silent. During courtship flight the male produces a soft 'tic..tic..tic' (30).
Behavior
Frequently seen perching high on a long grass stem and changing location with an undulating and weak flight. Seems to occur in small groups with males rare. An aerial hawker (74). This species is listed as 'vulnerable' as it undergoes extensive and continuing habitat loss (103).
Habitat and status
Local and rare in open protected grassland with scattered low bushes.
Distribution
Old sites mentioned by Pinto (40) near Guarulhos and Ipiranga are now part of the city of São Paulo and probably do not exist any more. Itirapina has a good population of this species. It might occur closer to the coast in suitable habitat.
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.
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
12 cm. A specialized grass tyrant with highly developed sexual dimorphism. In both sexes the bill is yellowish.
Male is black above with white cheeks, throat and belly. Rump gray. A black patch on the side of the breast. Secondaries with white patch.
The tail of the adult male may reach 19 cm and has the two center rectrices turned by 90° which then rise in a cocked position above the head level. The lateral rectrices form a steep plane on either side of the central tail feathers.
The female and young
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 (295 bytes lost in 2011)
12 cm. A specialized grass tyrant with highly developed sexual dimorphism. In both sexes the bill is yellowish.
Male is black above with white cheeks, throat and belly. Rump gray. A black patch on the side of the breast. Secondaries with white patch.
The tail of the adult male may reach 19 cm and has the two center rectrices turned by 90° which then rise in a cocked position above the head level. The lateral rectrices form a steep plane on either side of the central tail feathers.
The female and young are buffy brown, mottled darker above with a prominent white superciliary stripe. The wings are darker, the primaries and tertiaries with white fringes, the secondaries rusty-brown. Below white with a buff wash and a brown patch on the sides of the breast. Tail is short and has a normal shape.
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
Usually silent. During courtship flight the male produces a soft 'tic..tic..tic' (30).
Behavior Disc 1 · 2011
Frequently seen perching high on a long grass stem and changing location with an undulating and weak flight. Seems to occur in small groups with males rare. An aerial hawker (74). This species is listed as 'vulnerable' as it undergoes extensive and continuing habitat loss (103).
Habitat and status Disc 1 · 2011
Local and rare in open protected grassland with scattered low bushes.
Distribution Disc 1 · 2011
Old sites mentioned by Pinto (40) near Guarulhos and Ipiranga are now part of the city of São Paulo and probably do not exist any more. Itirapina has a good population of this species. It might occur closer to the coast in suitable habitat.
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 | alectrurus tricolor | Cock-tailed Tyrant | Tyrannidae,Fluvicolinae |
| CLEMENTS | alectrurus tricolor | Cock-tailed Tyrant | Tyrannidae,Fluvicolinae |
| AOU_HM | alectrurus tricolor | Cock-tailed Tyrant | Tyrannidae,Fluvicolinae |
Source details
- Identifier on this site
- seb_species_0261
- Account identifier
- seb_account_0261
- Account number on the disc
- 261
- Source edition
- CD03 / 2006 package
- Original taxonomy scheme
- WORLD
- Structure status
- heuristic; decoded_account_text and segment JSON remain authoritative