The Pitsford ‘American’ Wigeon

An interesting-looking juvenile/first-winter male wigeon, found at Pitsford Res on 10th October, exhibited some characteristics usually associated with American Wigeon and was subsequently identified as such. But was it one?

Still present yesterday afternoon, 12th October, in company with Eurasian Wigeons in Walgrave Bay, it provided an opportunity for prolonged observation, during which time it revealed some interesting and thought-provoking features.

Its standout, attention-grabbing appearance centred on the obvious dark oval eye-patch, set against an otherwise pale head and neck and a noticeably cold overall plumage tone, making it fairly easy to locate among the Eurasians.

There is much grey appearing on the mantle and the ‘orange’ juvenile feathers are being lost from the flanks, again revealing much grey. The emerging black undertail coverts and ventral area confirms this bird is a young drake.

The right-hand flanks retain more juvenile feathers than the left but grey (as in Eurasian Wigeon), not pinkish (as in American Wigeon) is coming through.

The rear flanks on this bird are also beginning to show the fine grey vermiculations of Eurasian Wigeon.

The bill base is plain in this bird, as is normally the case with Eurasian Wigeon but on most American Wigeons there is a thin, sharp black line running from the top to the bottom of the upper mandible, demarcating it from the feathering. This feature may take time to develop in younger birds, though.

While the above points are enough to arouse ID queries, the clincher, not shown in any of the images, is the colour of the axillaries, seen twice during the observation, when the bird flapped its wings while on the water. They were noted as being grey, as in Eurasian Wigeon and not white, which they would have been if the bird was an American Wigeon.

Based on the above, it is not possible to be certain if this bird carries any American Wigeon genes. Confusing back-crosses have been found to exist and an extensive library of images showing American Wigeon x Eurasian Wigeon hybrids can be viewed here.

Immatures do not readily reveal full hybrid characteristics until they have moulted into adult plumage and this is the likely case with this individual. Time will tell – if it stays around for the winter.