Species: Pink-necked Green Pigeon Treron vernans
Other common names: Pink-necked Green-pigeon, Pink-necked Green Pigeon, Pink-necked Pigeon.
Taxonomy: Treron vernans (Linnaeus) 1771, Luzon.
Sub-species & Distribution: Several forms of this species have been listed in early literature. Some of these, from the island groups off Sumatra, Java and Bali, whose variations are considered to be minor and clinal, might require further research to establish their validity. Three sub-species are currently recognised, extending its range from Myanmar, Thailand, Cambodia, Vietnam, Malaysia, Singapore, Indonesia and the Philippines. Only one race is found in this region:
Size: 8 to 9½" (22 to 24 cm). Sexes differ.
Description: Males: Crown, forehead and lores very pale bluish-grey, nape, sides of neck and upper breast purplish-lilac, paler on lower of face. Upper body, scapulars and tertials dark greyish-green, uppertail coverts tinged with yellowish-rufous. Tail dark bluish-grey with black terminal band, broader on outer rectrices, and thinly edged with grey. Seen from above, the tail appears slaty-blue with a black tip (Burknill & Chasen 1927). Primaries and primary coverts black. Secondaries black, inner ones narrowly edged yellow. Greater coverts elongated, and tertials, greyish-black broadly edged with pale yellow, forming a pale bar along the wing edges. Chin and upper throat pale bluish-grey, with a broad orange band across lower breast. Upper belly leaf-green, lightly marked with grey. Flanks greenish-yellow marked grey, more creamy-yellow marked with deep olive above vent. Vent pale creamy yellow. Underwing coverts and axillaries pale bluish-grey. Long dark cinnamon undertail coverts, extending almost to the tip of the tail.
Females: It has no grey, orange or lilac in the plumage. Generally dark greyish-green all over, paler and greener on forehead, sides of the head and upper breast, yellower on remaining underparts. Undertail coverts buffy-white marked with pale cinnamon.
Immature birds: Like the female, the wing coverts edged with buff. Young males probably do not completely acquire adult male plumage until the middle of the second year, and females have lesser coverts and tertials edged with pale sulphur-yellow (Robinson 1927).
Soft parts: Iris red to purplish-red. Bill pale bluish-grey, the cere and operculum pale greenish-yellow in males, greyer in females. Tarsi and feet purplish-pink, soles pale buff.
Status, Habitat & Behaviour: A common resident in secondary forest, scrub vegetation, orchards, parks, gardens and at the edges of clearings (Wang & Hails 2007). There are old records from Ubin, Tekong, Changi and the Botanic Gardens, more recent ones from Tekong, Ubin, Seletar, St John's, Senang, Berani, Sentosa, Semakau, Hantu, Pawai, Ayer Merbau (Wells 1999). In other parts of its range, it is common and more widely distributed, being found in scrub vegetation, the mangroves and along the edges of clearings, from the lowlands up to 1100 m. It is never found deep in the jungle, and rarely comes to the ground.
Usually seen singly, in pairs or in small groups during the breeding season, after which they assemble in large flocks and can be found feeding on fruiting trees, especially fig trees and in mangroves. They tend to be quarrelsome when feeding together, with a lot of squabbling taking place in the tree tops. Mostly arboreal, it perches conspicuously high up on the exposed tops of tall trees, often to bask in the early morning sun. During the evenings, flocks of thirty or more birds will congregate in regular feeding areas before flying off to roost in flocks. The birds appear about an hour before sunset, flock after flock following the same route until dark, headed for favourite roosting places in high trees or, if by the coast, in the mangroves (Burknill & Chasen 1927). Its flight is very fast and direct.
Food: Largely frugivorous. They eat soft fruit, largely figs and berries of all kinds. On wastelands, they regularly feed on the sticky fruit of the Straits Rhododendron Melastoma malabathricum, and the Singapore Cherry Muntingia calabura. They have been seen eating the flower petals and seeds of the Simpoh Air Dillenia suffruticosa (J. Wee 2008). They are particularly fond of several fruiting fig trees, the following trees having been identified as food sources: the Common Yellow-Stemmed Fig Ficus fistulosa and the White-leafed Fig Ficus grossularioides (Y.C. Wee 2007), the Weeping or Benjamin's Fig Ficus benjamina (Amar-Singh 2010), the Sacred Fig or Bodh Tree Ficus religiosa. They also eat fruit from the MacArthur Palm Ptychospermum macarthurii by swallowing it whole (Huang 2009). It has been seen eating the fruit from the Indonesian Bay Leaf or Salam Tree (Y.C. Wee 2010).
Voice and Calls: It has a distinctive high-pitched cooing whistle, ooo-ooo, cheweoo-cheweoo-cheweoo, the 2nd note much longer.
Breeding: Nest building has been recorded between March to May, and August, nestlings in February, April, May and July, immature birds in March, July and September (Wang & Hails 2007), an extended series of records that suggests that they may be double-brooded. The breeding season is largely dependent on the fruiting of certain species of figs (Robinson 1927). This bird appears to be more common now and has been found nesting in residential areas, even in potted plants (Kok 2008).
The nest is a fragile platform made of loose twigs, with a central concavity, set in the fork of a branch, sometimes as little as 3 to 5 feet above the ground, mostly in low shrubs, small trees, in bamboo clumps or high up a coconut palm. In mangroves, it is usually placed six to twenty-five feet above ground and, occasionally, the nest is lined with dry leaves (Robinson & Chasen 1936). The male collects and passes twigs to female as she sits in the developing nest, but appears not to build (Wells 1999).
The normal clutch size is one or two white eggs, with very little gloss. The average size is 1.08" x 0.85" (27.4 x 21.5 mm) according to Robinson (1927), or 26.8 - 28.9 x 20.3 - 21.8 mm (Wells 1999). Both sexes share parental duties, incubating the eggs for about 17 days, and taking care of the near-naked nestlings, the male by day, the female throughout the night (Y.C. Wee 2006). For the first few days, the nestlings are fed with regurgitated crop milk, a secretion produced by the parents (Chan 2007).