Steller's eider

Steller's eider (Polysticta stelleri) is a smallish sea duck that breeds along the Arctic coasts of eastern Siberia and Alaska.

Steller's eider
A drake
A duck
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Anseriformes
Family: Anatidae
Genus: Polysticta
Eyton, 1836
Species:
P. stelleri
Binomial name
Polysticta stelleri
(Pallas, 1769)

Description

This species is the smallest eider at 45 cm (18 in) long.[2] The male is unmistakable with his white head marked by a thick black eye ring and greenish-black tufts of feathers on the forehead and the back of the head. Chin, throat and neck are also black, as are the back, tail, and rump. Wings are dark bluish-purple with white edging. When folded, they give a striped appearance across the back. The speculum is metallic blue bordered with white. The breast and flanks are cinnamon-buff marked with a black spot on each side just above the waterline. Legs, feet and bill are dark bluish-grey.[3]

The female is a dark brown bird, smaller with a more typically duck-shaped head and body than other eider species.

The drake's call is a deep crooning, although it is relatively quiet compared to the Somateria eiders. The hen also has a repertoire of grunts and whistles.

Standard Measurements[3][4]
length430–460 mm (17–18 in)
weight860 g (1.90 lb)
wingspan690 mm (27 in)
wing210–225 mm (8.3–8.9 in)
culmen37–42 mm (1.5–1.7 in)
tarsus36–40 mm (1.4–1.6 in)

Ecology

The lined nest is built on tundra close to the sea, and 6–10 eggs are laid.

It winters somewhat farther south in the Bering Sea, northern Scandinavia and the Baltic Sea. It can form large flocks of up to 200,000 birds on suitable coastal waters. It is scarce south of its wintering range.

This species dives for crustaceans and molluscs, with mussels being a favoured food.

The genus name is derived from Ancient Greek polustiktos, "much spotted", from polus "many" and stigme "spot". The species name is for German naturalist and explorer Georg Steller.[5]

Hybridisation

The Steller's eider is thought to have hybridised with the common eider on at least two occasions in the wild. A drake showing characteristics of both species was present at Cuxhaven, Niedersachsen, Germany, on 17 November 1993.[6] Another drake was seen in Vadso harbour, Varanger, Norway, on 7 April 1995; a photograph of this bird was published accompanying Forsman (1995).[7]

Hybridisation with mallard ducks is also thought possible.[8]

Conservation

The Steller's eider is one of the species to which the Agreement on the Conservation of African-Eurasian Migratory Waterbirds (AEWA) applies. There is an active recovery plan in Alaska.[9]

gollark: I don't run on them any more.
gollark: No, that's one of our older computers.
gollark: Wow, that'll definitely work.
gollark: There are uncountably infinitely many, so assuming a finite, nonzero sale price for each, I'll have uncountably infinite money.
gollark: I should make apioform NFTs to fund our operations.

References
  1. BirdLife International (2013). "Polysticta stelleri". IUCN Red List of Threatened Species. 2013. Retrieved 26 November 2013.CS1 maint: ref=harv (link)
  2. Fredrickson, Leigh H. (2001). Poole, A. (ed.). "Steller's Eider (Polysticta stelleri)". The Birds of North America Online. Ithaca: Cornell Lab of Ornithology. doi:10.2173/bna.571.
  3. Godfrey, W. Earl (1966). The Birds of Canada. Ottawa: National Museum of Canada. p. 75.
  4. Sibley, David Allen (2000). The Sibley Guide to Birds. New York: Knopf. p. 96. ISBN 0-679-45122-6.
  5. Jobling, James A (2010). The Helm Dictionary of Scientific Bird Names. London: Christopher Helm. pp. 313, 365. ISBN 978-1-4081-2501-4.
  6. "Hybrid coincidence". Birding World. 8 (5): 200. 1995.
  7. Forsman, Dick (1995). "A presumed hybrid Steller's eider x common eider in Norway". Birding World. 8 (4): 138.
  8. McCarthy, E M. 2006. Handbook of Avian Hybrids of the World, page 36. Oxford University Press.
  9. "Steller's Eider Recovery Plan" (PDF). Fairbanks, Alaska: U.S. Fish and Wildlife Service. 2002.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.