| 词条 | Blue-winged goose |
| 释义 |
| name = Blue-winged goose | status = VU | status_system = IUCN3.1 | status_ref = [1] | image = Blue-winged Goose RWD2.jpg | image_caption = At Sylvan Heights Waterfowl Park | genus = Cyanochen | parent_authority = Bonaparte, 1856 | species = cyanoptera | authority = (Rüppell, 1845) | synonyms =Cyanochen cyanopterus (Rüppell, 1845) }} The blue-winged goose (Cyanochen cyanoptera) is a waterfowl species which is endemic to Ethiopia. It is the only member of the genus Cyanochen. RelationsThe relations of this species among the waterfowl is unresolved. It is morphologically close to shelducks, and particularly the South American sheldgeese, which have highly similar courtship displays.[2] However, mitochondrial DNA sequence analyses of the cytochrome b and NADH dehydrogenase subunit 2 genes indicates that it might belong to a very distinct and ancient "duck" clade, together with Hartlaub's duck, another African species of uncertain affinities.[3] The wing color pattern, a good morphological indicator of evolutionary relationships in waterfowl, is similar in these two species, and very different from any other waterfowl.[3][4] DescriptionThis is a stocky grey-brown bird about {{convert|70|cm|in}} long with a slightly paler head and upper neck. It has a small black bill and black legs. In flight, this species shows a pale blue forewing. Sexes are similar, but immature birds are duller. The plumage of these birds is thick and loose, furlike as an adaptation to the cold of the Ethiopian highlands.[2] VoiceThe blue-winged goose is a quiet species, but both sexes may give a soft whistle; it does not honk or cackle like the true geese. HabitatThe habitats of the blue-winged goose are primarily rivers, freshwater lakes, swamps, freshwater marshes, water storage areas, and subtropical or tropical high-altitude shrubland or grassland. BehaviourIt feeds by grazing, and is apparently largely nocturnal, loafing during the day. It can swim and fly well, but this terrestrial bird is reluctant to do either, and is quite approachable. It forms flocks outside the breeding season. It breeds by mountain lakes and streams. This little-known species is believed to build a lined nest amongst grass tussocks, and to lay 6–7 eggs. StatusIt is threatened by habitat loss, trapping for food and possibly drought. Formerly classified as a Near Threatened species on the IUCN Red List, new research has shown it to be rarer than it was believed. Consequently, it is uplisted to Vulnerable status in 2008.[5][6] References1. ^{{IUCN|id=22679961 |title=Cyanochen cyanoptera |assessor=BirdLife International |assessor-link=BirdLife International |version=2013.2 |year=2012 |accessdate=26 November 2013}} 2. ^1 {{Cite book | last = Kingdon | first1 = J. | title = Island Africa: The Evolution of Africa's Rare Plants and Animals | location = Princeton | publisher = Princeton University Press | year= 1989 | isbn = 0-691-08560-9}} 3. ^1 {{Cite journal | last = Johnson | first = Kevin P. |author2=Sorenson, Michael D. | title = Phylogeny and biogeography of dabbling ducks (genus Anas): a comparison of molecular and morphological evidence | journal = Auk | volume = 116 | issue = 3 | pages = 792–805 | year = 1999 | url = http://sora.unm.edu/sites/default/files/journals/auk/v116n03/p0792-p0805.pdf | accessdate = 1 January 2009 | doi = 10.2307/4089339}} 4. ^{{Cite book | last = Madge | first = Steve |author2=Burn, Hilary | title = Wildfowl: an Identification Guide to the Ducks, Geese and Swans of the World | publisher = Christopher Helm | year = 1987 | location = London | isbn = 0-7470-2201-1}} 5. ^{{IUCN2008|assessor=BirdLife International|year=2008|title=Cyanochen cyanoptera|id=22679961|downloaded=5 November 2009}} 6. ^{{Cite web | author = BirdLife International | authorlink = BirdLife International | title = 2008 IUCN Redlist status changes | year = 2008 | url = http://www.birdlife.org/datazone/species/downloads/2007-2008_category_changes.xls | format = Excel Spreadsheet | accessdate = 23 May 2008}} External links
4 : Geese|Tadorninae|Endemic birds of Ethiopia|Birds described in 1845 |
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