The spotted green pigeon or Liverpool pigeon (Caloenas maculata) is a species of pigeon which is most likely extinct. It was first mentioned and described in 1783 by John Latham, who had seen two specimens of unknown provenance and a drawing depicting the bird. The taxonomic relationships of the bird were long obscure, and early writers suggested many different possibilities, though the idea that it was related to the Nicobar pigeon (C. nicobarica) prevailed, and it was therefore placed in the same genus, Caloenas. Today, the species is only known from a specimen kept in World Museum, Liverpool. Overlooked for much of the 20th century, it was recognised as a valid extinct species by the IUCN Red List only in 2008. It may have been native to an island somewhere in the South Pacific Ocean or the Indian Ocean, and it has been suggested that a bird referred to as titi by Tahitian islanders was this bird. In 2014, a genetic study confirmed it as a distinct species related to the Nicobar pigeon, and showed that the two were the closest relatives of the extinct dodo and Rodrigues solitaire. The surviving specimen is 32 cm (13 in) long, and has very dark, brownish plumage with a green gloss. The neck feathers are elongated, and most of the feathers on the upperparts and wings have a yellowish spot on their tips. It has a black bill with a yellow tip, and the end of the tail has a pale band. It has relatively short legs and long wings. It has been suggested it had a knob on its bill, but there is no evidence for this. Unlike the Nicobar pigeon, which is mainly terrestrial, the physical features of the spotted green pigeon suggest it was mainly arboreal, and fed on fruit. The spotted green pigeon may have been close to extinction by the time Europeans arrived in its native area, and may have disappeared due to over-hunting and predation by introduced animals around the 1820s.
Taxonomy
The spotted green pigeon was first mentioned and described by the English ornithologist John Latham in his 1783 work A General Synopsis of Birds. Latham stated that he had seen two specimens, in the collections of the English major Thomas Davies and the naturalist Joseph Banks, but it is uncertain how these ended up in the respective collections, and their provenance is unknown. Though Banks received many specimens from the British explorer James Cook, and Davies received specimens from contacts in New South Wales, implying a location in the South Pacific Ocean, there are no records of spotted green pigeons having been sent from these sources. After Davies' death, his specimen was bought in 1812 by Edward Smith-Stanley, 13th Earl of Derby, who kept it in Knowsley Hall. Smith-Stanley's collection was transferred to the Derby Museum in 1851, where the specimen was prepared from the original posed mount (which had perhaps been taxidermied by Davies himself) into a study skin. This museum later became the World Museum, where the specimen is housed today, but Banks' specimen is now lost. Latham also mentioned a drawing of a spotted green pigeon in the collection of the British antiquarian Ashton Lever, but it is unknown which specimen this was based on; it could have been either, or a third individual. Latham included an illustration of the spotted green pigeon in his 1823 work A General History of Birds, and though the basis for his illustration is unknown, it differs from Davies' specimen in some details. It is possible that it was based on the drawing in the Leverian collection, since Latham stated that this drawing showed the end of the tail as "deep ferruginous" (rust-coloured), a feature also depicted in his own illustration. The spotted green pigeon was scientifically named by the German naturalist Johann Friedrich Gmelin in 1789, based on Latham's description. The original binomial name Columba maculata means "spotted pigeon" in Latin. Latham himself accepted this name, and used it in his 1790 work Index ornithologicus. Since Latham appears to have based his 1783 description on Davies' specimen, this can therefore be considered the holotype specimen of the species. Subsequent writers were uncertain about the validity and relationships of the species; the English naturalist James Francis Stephens suggested that it belonged in the fruit pigeon genus Ptilinopus in 1826, and the German ornithologist Johann Georg Wagler instead suggested that it was a juvenile Nicobar pigeon (Caloenas nicobarica) in 1827. The Italian zoologist Tommaso Salvadori listed the bird in an appendix about "doubtful species of pigeons, which have not yet been identified" in 1893. In 1898, the Scottish ornithologist Henry Ogg Forbes supported the validity of the species, after examining Nicobar pigeon specimens and concluding that none resembled the spotted green pigeon at any stage of development. He therefore considered it a distinct species of the same genus as the Nicobar pigeon, Caloenas. In 1901, the British zoologist Walter Rothschild and the German ornithologist Ernst Hartert agreed that the pigeon belonged to Caloenas, but suggested that it was probably an "abnormity", though more than one specimen had been recorded.
… excerpt ends here. Continue reading the full article.
