|A record shot of the Connaught Water Green-winged Teal or hybrid (left), with a drake Eurasian Teal (right). On the former, note the 'incomplete' fore-flank stripe, narrow white scapular line, breast colour and head pattern.|
|An even more distant shot of the same bird (right), with a presumed female Eurasian Teal (left), cropped in to show|
the other white vertical fore-flank stripe, which is also a little broken up.
Like Eurasian Teal, Green-winged has a horizontal black scapular line, formed by black outer webs to the lower scapulars, but it is often less obvious than in Eurasian; importantly, the inner webs of these feathers are brownish-grey and, while they may appear pale, do not contrast boldly with the back, unlike the broader white scapular stripe of Eurasian. In this respect the Connaught Water bird is looking ropey, showing a narrow white margin above the black scapular line which seems no different to how a hybrid would look (for example, compare the images here).
The head pattern can also be debated. There is a distinct pale edge to seemingly much of the green head sides which, though not as clear-cut as on male Eurasian Teal, is apparently more extensive than on typical Green-winged Teal (in the upper photo above it can be seen to run narrowly around the top of the green blaze and down to the bill base, rather than being restricted to the underside). The head colour itself seems very close to Eurasian Teal, not darker brown in tone (a feature mentioned in Sibley but not in the Collins Bird Guide). Check the two shots below to see this difference between more clear-cut individuals of both species, and compare the other features:
|Drake Green-winged Teal (Co Clare, Ireland, March 2010). Head colour and pattern, the warmly toned breast and finely vermiculated grey flanks, appearing almost hazy, are useful supporting features to the bold vertical white stripe.|
|Drake Eurasian Teal (Connaught Water, Greater London, March 2011). The pale border to the brighter brown head is clearly more obvious in Eurasian Teal, though also variable. The grey flanks are much more coarsely patterned.|
|A closer crop on the record shot of the Connaught Water teal published at the top of this post. The horizontal white scapular stripe is unequivocally white, a feature (albeit more prominently) associated with Eurasian Teal.|