Canadian Eiders in the North Sea

by 

Norman D. van Swelm 

(The Birds of The Palaearctic Fauna, Non-Passeriformes, 1965)

 wrote on Somateria mollissima borealis: 'Platypus borealis' C.L.Brehm, 1824, Lehrb. Naturgesch. aller europ. Vögel, 2, p. 813, coasts of Baffin Bay and Davis Strait and west coast of Greenland.

01-Northern Canada Eider S.m.borealis male 6th January 2003 1 sail visible Brouwersdam, The Netherlands:

Canadian Eiders in the North Sea

Charles Vaurie: Similar to nominate mollissima but the adult male differs from the latter by the colour of the bill which is orange or yellowish, rather than greenish yellow, and by having a white lateral lobe somewhat shorter, usually not reaching or projecting beyond the posterior border of the nostril as in nominate mollissima. The female is slightly more reddish, and the wing and bill average shorter than in typical nominate mollissima from Scandinavia.

Range: North-eastern North America on Ellesmere, Cornwallis, and Somerset islands, south to Baffin and Southampton islands and Ungava Bay in northern Labrador, coasts of Greenland, Iceland, Jan Mayen, Bear Island, Spitsbergen, and the southern islands of Franz Josef Land. Winters on the coasts of south-western Greenland and eastern Labrador south to Nova Scotia, occasionally to Maine, and rarely to Massachusetts and Connecticut.

NDvS: Without further explanation Vaurie thus expanded the breeding range of borealis as described by Brehm to as far east as Franz Josef Land! The only reason one can think of is that Vaurie believed that the breeding males from Greenland to further east have orange or yellowish bills, but have they? In any case the male breeding Eiders from Spitsbergen have greenish and not orange or yellowish bills (various sources and photo's)! Even the few known pictures of breeding males from western Greenland don't show orange or yellowish bills. So one wonders if Brehm's description is not closer to the truth than Vaurie's. Garner & Farrelly (CLICK TO SEE:

http://www.ornithomedia.com/pratique/identif/ident_art52_1.htm      OR: http://www.birdsireland.com/pages/site_pages/features/eider/eider.html)

discovered that arctic Eiders can show 'sails' which they describe as 'two stiffer, modified long scapulars'. According to Garner & Farrelly these 'sails' are 'not easily discernible on skins'. In fact they are not easily discernible on live birds as well! On most pictures we have seen of arctic Eiders there is not a 'sail' in sight! Garner & Farrelly also noticed that male Eiders east of Greenland have greenish not orange bills hence they figure there must be a cline from east to west where green bills eventually become orange. They even go so far that a claimed borealis in Britain and Ireland 'must show obvious presence of white sails' and therefore making the bill colour of secondary importance. Yet it was the colour of the bill which made Brehm, Vaurie and others decide to give borealis a status of it's own! The discovery of the presence of 'sails' in northern Eiders by Garner & Farrelly is of course very interesting and their confusion over the bill colour caused by Vaurie understandable however claiming a cline from east to west may not be the answer. Given the geological and climatological history of the area, it seems more appropriate to separate the green bills from the orange bills. So I propose to re-acknowledge the northeast Canadian orange-billed (male) Eiders as borealis : the Canadian Eider and the green-billed arctic Eiders as arctica : the Greenland Eider!

Occasionally Canadian Eiders are seen in the North Sea, in particular during winters with long spells of westerly or north-westerly winds over the Atlantic such as the present winter of 2006-2007. Canadian Eiders are easily separated from the local nominate race by their orange-bills. As for 'sails', only one picture of the male I found along the Dutch coast in January 2003 shows one 'sail'. The male I found on 27th January 2007 never raised it's 'sails' while I was present. It's mate is very 'gingery' in line with Vaurie's description of female borealis and quite similar to the female with 'sails' in the pictures from Ireland.

> http://www.roysephotos.com/CommonEider.html

Acknowledgements: Bruce Mactavish, Jean Iron, Ron Pittaway.