Rock Dove

columba livia

Columbidae · Pigeons, Doves

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

The account

Description

31-34 cm. The ancestor of the domestic pigeon.

Head and rump bluish slaty gray, wing coverts paler. Two black wingbars and black terminal tail bar. Side of neck with purplish green iridescence. Feral domestic pigeons can have diverse color patterns.

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

Where it was recorded

The discs' own checklists select Rock Dove at 4 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.

Jureia-Peruibe JUSB position not recoverable
Marica MRRB
Parati PARB
Serra da Cantareira SRSB

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

Advertising call a deep 'oorrh oorrh', display call more hurried 'oo oo oo oo' (¹¹⁸).

Behavior

Feeds on the ground on fruits, offal, etc. Roosts on buildings in large flocks. In the bowing display the male flies to the female with clapping wings and alights close to the female; it follows the female in circles with nodding movements and coo-ing.

Habitat and status

Common in cities and towns. Does not occur in wooded areas or parks. Also inhabits cliffs and caves and feeds in the open country in agricultural areas in flocks.

Distribution

Throughout.

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

Boston, MA, USA

Recording files on the disc

2312.wav Boston, MA, USA

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 edited this account; the sections listed below differ from the Disc 3 release text.

Sections with genuine 2011 edits (vs the Disc 3 release): description; breeding.

Description Disc 1 · 2011

31-34 cm. Head and rump bluish slaty gray, wing coverts paler. Two black wingbars and black terminal tail bar. Side of neck with purplish green iridescence. Feral domestic pigeons can have diverse color patterns. Feral Rock Doves are derived from the domestic pidgeon and can have diverse color patterns.

Voice Disc 1 · 2011