Colomba dal ciuffo

Identificazione

The topknot pigeon is a large predominately slate-grey bird, 40–46 centimetres (16–18 in) in length. The back, coverts and upper secondaries are a darker slate-grey with black quills. The primaries are black, the remaining body in a lighter slate-grey in colour. The chest and hind neck are notched, showing dark bases giving a streaked appearance.[2] The tail is black crossed with a board grey band. The crest is grey from the cere to the forehead, and russet brown on the crown with black sides. The mandibles are red with a brown tip, the protuberances at the base of the mandibles are bluish-green. The tarsals and feet are purplish red. The sexes are similar in description. However, Males have larger crest and lack some of the streaking on the chest. Juveniles are like females but the chest is mottled not streaked, the crest is smaller, with the cere and forehead being light brown, the crown grey. Tarsals and feet are reddish brown. The iris is yellow-golden with a bright red outer band. In fledglings the iris is brown.[2]

Tassonomia

English naturalist George Shaw described the topknot pigeon as Columba antarctica in 1793.<p>The topknot pigeon is sister taxon to a lineage that gave rise to the mountain pigeons (Gymnophaps) of New Guinea, the common ancestor of both diverged from a lineage that gave rise to the kererū and Chatham pigeon.<p>"Topknot pigeon" has been designated the official common name by the International Ornithologists' Union (IOC); John Gould noted in 1848 that it had been given this name by the colonists of New South Wales. It is also known by the name of "flock pigeon".

Nome scientifico

Lopholaimus antarcticus

Autorità

(Shaw, 1793)

Ordine

Columbiformi

Famiglia

Columbidae

Genere

Lopholaimus

Areale e habitat

Found from the Cape York Peninsula in Queensland to the central south coast of New South Wales. These pigeons cover great distances in search of fruit bearing trees suddenly appearing in areas where they have not been seen for many years and will occasionally move beyond their normal southern range limit, into eastern Victoria.[2] Historic records from 1953 show the topknot pigeon as an "accidental" species to Tasmania with a specimen taken at Spreyton near Devonport. This bird was one of a flock of 9-10 birds feeding on cherries. Previous to this sighting, the only other recording was in 1907 when two specimens were taken near St. Helens, east coast of Tasmania. The Spreyton specimen is held in the Tasmania Museum, Collection Number 13184/B2703.

Migrazione

Nomadic movement

Conservazione

The species used to occur in enormous numbers in Australian rainforest, but the population declined because of forest clearance and shooting. Because of concern over the steep decline in their population, topknot pigeons now are a protected species in Australia. However the increasing prevalence of a new food source in the fruit of the 'weed' camphor laurel trees has seen a recent resurgence in their number.[citation needed] As populations appear to be fluctuating but large, the species is currently classified as Least concern by the IUCN.

Tendenza della popolazione

declining