Tuesday 26 March 2013

Rare duck in Scotland!

March 21, 2013: A few hours in Edinburgh
March 22, 2013: Oban, Scotland
March 26, 2013: Rare duck in Scotland!
March 26, 2013: Aberlady Bay, Scotland
March 30, 2013: Unique photo of a lifer (Paris, France)
March 31, 2013: Photos d'oiseaux de France (Paris, France)
April 2, 2013: Seabird die-off on the east coast of Scotland

Today, Laura and I headed over to Aberlady Bay, east of Edinburgh along the coast, to see what birds we could find throughout the afternoon. I will make a full post about this trip eventually, but right now I will just post some pictures of a potential rare bird we came across.

As we were leaving the main estuary area and heading back to the town of Aberlady, I was keeping an eye on the shorebirds (mostly Dunlin, Euro Oystercatchers, and Euro Curlews) and ducks (mostly Common Teal, Eurasian Wigeon, Common Eiders, Mallards, and Common Shelducks). Four wigeon were relatively close to us, so I stopped to scan them. 2 male Eurasian, 1 female Eurasian, and 1 odd looking and familiar wigeon. It appeared to be a female American Wigeon; a species I am very familiar with in Ontario but not one I was expecting in Scotland. However it is a tough call with female wigeons, so I tried to document the bird with photos as it sat in the grass.

putative American Wigeon (left) with Jackdaw (right) - Aberlady Bay, Scotland

Here is another photo from a little closer. In the above photo, the grayish head really stands out (compared to the deeper brown head of a Eurasian Wigeon). In the following photo you can see the faint black line along the gape (proximal edge of the bill) which is apparently diagnostic for American Wigeon.

putative American Wigeon - Aberlady Bay, Scotland

Of course, a shot of the wings would be needed to clinch the ID. Fortunately for us, the 4 birds eventually got up and flew (the tide was going out and the ducks were constantly coming and going). I was able to get a series of photos including one showing the white auxillaries on the underside of the wing. Eurasian Wigeon has an all gray underwing most of the time.

putative American Wigeon (right) with Eurasian Wigeon - Aberlady Bay, Scotland

In this photo, the two male Eurasian Wigeons are on the left, next is the putative American Wigeon, and on the right is a female Eurasian Wigeon. Note the difference in underwing pattern in the two female wigeons, as well as the lighter gray head on the putative American versus the darker brown head on the Eurasian.

putative American Wigeon (second from right) with Eurasian Wigeon - Aberlady Bay, Scotland

Does anybody have any thoughts on this bird? Bruce MacTavish, are you reading? It looks good to me but I don't want to jump the gun. Apparently there are 3 previous records for the Lothians, with the last coming in 1998.


Bruce Mactavish said...

Second attempt to post from a feeble internet connection in Nunavut.

Josh, The head of your wigeon shows a brownish cast on my laptop. We'd call this a EUWI in Newfoundland. However, what you saw in the field might not be what I see on my 14"screen. On a bird so rare I'd want to see a more standard bright ashy gray head of a typical AMWI, especially by spring. The axillar looks surprisingly white for a EUWI and there is a true EUWI in the same shot giving something for comparison. I am not sure of the limits of the this feature on the two wigeons. There appears to be some gray on the webs of some of those feathers. Sometimes when female EUWI are flying over head I am surprised how whitish the underwings can look in a fleeting view. I think of AMWI as having snow white axillars but it is a feature difficult to see well in life.

BTW the head colour of female EUWI range widely from orangey-brown to middle of the road brown to a brown barely browner than gray (if that makes sense). Only occasionally to we see a female wigeon in St. John's where we can't decide if the underlying colour of the head is brown or gray. We just let the identification go on such birds.

Don't spoil your Scottish vacation on female wigeons! Go see some good birds.

B Mactavish

Anonymous said...

The bird was relocated yesterday, and is now being reported as an American Wigeon on the Scottish listservs.

Bruce, what are your thoughts on the black line along the gape of the bird? From what I've read, EUWI should never have the black line, and AMWI usually has it. It appears that this bird has a black edge to the gape.