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The white-winged scoter (Melanitta deglandi) is a large sea duck. The genus name is derived from Ancient Greek melas "black" and netta "duck". The species name commemorates French ornithologist Côme Damien Degland.
|Adult male of the American race deglandi|
Melanitta fusca deglandi
The white-winged scoter is one of three North American scoter species and the largest species of scoter. It is characterised by its bulky shape and large bill. Females range from 950–1,950 g (2.09–4.30 lb) and 48–56 cm (19–22 in), averaging 1,180 g (2.60 lb) and 52.3 cm (20.6 in). She is brown with pale head patches. The male ranges from 1,360–2,128 g (2.998–4.691 lb) and from 53–60 cm (21–24 in), averaging 1,380 g (3.04 lb) and 55 cm (22 in). He is all black, except for white around the eye and a white speculum. This scoter's bill has a black base and a large knob.
There are a number of differing characteristics of the Stejneger's scoter and the white-winged scoter. Males of the white-winged scoter have browner flanks, dark yellow coloration of most of the bill and a less tall bill knob, approaching the velvet scoter. Stejneger's scoter has a very tall knob at the base of its mostly orange-yellow bill. Females are identical in the field.
The Latin binomial commemorates the French zoologist Dr. Côme-Damien Degland (1787–1856).
It was formerly considered to be conspecific with the velvet scoter, and some taxonomists still regard it as so. These two species, the Stejneger's scoter, and the surf scoter, are placed in the subgenus Melanitta, distinct from the subgenus Oidemia, black and common scoters. Stejneger's scoter was suggested to be a full species, according to a new study.
The white-winged scoter breeds over the far north of North America. It winters further south in temperate zones, on the Great Lakes, the coasts of the northern United States and the southern coasts of Canada.. It forms large flocks on suitable coastal waters. These are tightly packed, and the birds tend to take off together. It has occurred as a vagrant in Europe, including Scotland, Iceland, Norway and Ireland,
The lined nest is built on the ground close to the sea, lakes or rivers, in woodland or tundra. 5–11 eggs are laid. The pinkish eggs average 46.9 mm (1.85 in) in breadth, 68.2 mm (2.69 in) in length and 82.4 g (2.91 oz) in weight. The incubation period can range from 25 to 30 days. After about 21 days, neighboring females may start to behave aggressively towards other nesting females, resulting in confusion and mixing of broods. By the time she is done brooding, a female may be tending to as much as 40 offspring due to the mixing from these conflicts. The female will tend to her brood for up to 3 weeks and then abandon them, but the young will usually stay together from another 3 weeks. Flight capacity is thought to be gained at 63 to 77 days of age.
In freshwater, this species primarily feeds on crustaceans and insects; while in saltwater areas, it feeds on molluscs and crustaceans. The favorite foods are an amphipod (Hyalella azteca) in freshwater, and rock clams (Protothaca staminea), Atlantic razor clams (Siliqua spp.), and Arctic wedge clams (Mesodesma arctatus).
- BirdLife International (2018). "Melanitta deglandi". The IUCN Red List of Threatened Species. 2018: e.T22734194A132663794. Retrieved 23 December 2018.
- Jobling, James A (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. pp. 132, 246. ISBN 978-1-4081-2501-4.
- "Siberian Scoter (Melanitta stejnegeri)".
- "Changes to the British List". British Ornithologists' Union. 5 December 2013. Retrieved 23 December 2018.
- "American White-winged Scoters in Iceland". The Icelandic Birding Pages. Gunnlaugur Pétursson / Yann Kolbeinsson. Retrieved 23 December 2018.
- Martin Garner (2014). "Velvet, White-winged and Stejneger's Scoters: A Photographic Guide" (PDF). Birdwatch. Retrieved 23 December 2018.
|Wikimedia Commons has media related to Melanitta deglandi.|
|Wikispecies has information related to Melanitta deglandi|
- BirdLife species factsheet for Melanitta deglandi
- "Pitangus sulphuratus". Avibase.
- "White-winged scoter media". Internet Bird Collection.
- White-winged scoter photo gallery at VIREO (Drexel University)
- White-winged Scoter Species Account – Cornell Lab of Ornithology
- Interactive range map of Melanitta deglandi at IUCN Red List maps
- Audio recordings of White-winged scoter on Xeno-canto.