Sao Tome Pigeon

Identificazione

The island bronze-naped pigeon is a small, darkish pigeon with a total length of 28 cm (11 in) and a wing length of 178–182 mm (7.0–7.2 in) in males and 165–176 mm (6.5–6.9 in) in females. In adult males, the crown (top of the head), forecrown, hindcrown, back of the neck, and mantle are slaty-grey, with the last three having a glossy pink or green sheen. The wings and back down to the top of the tail are blackish-grey with a greenish tinge. The chin and throat are buffy-white, while the breast and belly are pale ashy-grey. The vent and underside of the tail are rufous with grey spots, while the upper side of the tail is blackish-grey with a yellowish-brown wash on the edges of the rectrices. The eye-ring is narrow and light grey and the iris is pale grey. The bill is dark grey with a pale tip, and the feet are red.<p>Females are similar to males, but have browner undersides, with fine yellow-brown speckling on the lower breast and upper belly. The lower belly down to the vent is pale rufous with grey speckling. The upperparts are duller and less glossy, and the outer tail feathers are more rusty-orange. Juveniles are like females but browner overall, with less iridescence on the back of the neck, ochre or rufous freckles on the upperparts, and buff edges to the feathers of the crown and forecrown.<p>The species is similar in appearance to the closely related western and eastern bronze-naped pigeons, but does not co-occur with them in any part of its range. On São Tomé, it may be confused with the São Tomé olive pigeon and São Tomé lemon dove. The olive pigeon is larger, with white spots on the lower breast and wings. Males are also maroon; females are more similar in colour, but are generally darker grey than the island bronze-naped pigeon. The lemon dove is more terrestrial in its habits and plumper appearance. It also has duller and less extensive green iridescence, as well as red orbital skin and irises.<p>The advertising call consists of two hoarse hoots followed by 15–20 stuttering notes, "rhuuuw...rhuuw...rhu-tu-tu-tu-tutututu", with the later notes being shorter and eventually fading away. It is quite distinct from the calls of the other bronze-naped pigeons, and is more reminiscent of Streptopelia doves in its tone and structure. The species also makes nasal "wuh..wuh..." calls when feeding.

Tassonomia

The island bronze-naped pigeon was described as Columba Malherbii in 1851 by Jules and Édouard Verreaux based on specimen from São Tomé, although they erroneously mentioned the type locality as being "Gaboon". The generic name is derived from the Latin word columba, meaning 'pigeon' or 'dove'. The specific name malherbii is in honour of Alfred Malherbe, a French jurist and ornithologist. Island bronze-naped pigeon is the official common name designated by the International Ornithologists' Union. Other common names for the species include São Tomé bronze-naped pigeon, São Tomé grey pigeon, São Tomé pigeon, and Malherbe's pigeon. It has no subspecies.<p>The island bronze-naped pigeon is one of 35 species in the genus Columba in the pigeon family Columbidae. It is occasionally considered to be the same species as the western and eastern bronze-naped pigeons; these three species are also sometimes placed in the subgenus Turturoena.

Nome scientifico

Columba malherbii

Autorità

Verreaux, J & Verreaux, É, 1851

Ordine

Columbiformi

Famiglia

Columbidae

Genere

Columba

Areale e habitat

The island bronze-naped pigeon is endemic to the Gulf of Guinea, where it occurs on the islands of São Tomé and Príncipe in São Tomé and Príncipe, and Annobón in Equatorial Guinea. On Annobón, it inhabits rainforest at elevations of up to 500 m (1,600 ft) above sea level. On Príncipe, it inhabits forests and plantations, and is considerably less common in primary forest than other similar species. On São Tomé, it also inhabits forests and plantations, but is more common in human-modified habitats like shade forests and non-forested areas like savannas. It occurs at elevations of up to 1,668 m (5,472 ft), but is more common at lower elevations and is absent from high-elevation forests on São Tomé.

Migrazione

Specie stanziale

Comportamento

Comportamento migratorio: Specie stanziale.

Conservazione

Tendenza della popolazione: in diminuzione.

Tendenza della popolazione

in diminuzione