I have always been fascinated by the feather patterns on the male Gadwall (Anas Strepera) but only recently managed to get one reasonable image to post here.
If you looked up the definition of Gadwall it would probably state this is a drably greyish-brown, medium sized dabbling duck but in my view that doesn't do it justice. In full breeding plumage the head of the male is brown but the rest of the body is a series of finely vermiculated grey which is boldest on the breast and its long scapulars are a pale grey-buff. Of course when scanning for this species the most obvious diagnostic features would be its black stern and a small white speculum (not visible on the above image) which is far more prominent when the duck is in flight. The origin of the name 'Gadwall' is unknown (probably from the mid 17th century) but I am glad that this delightfully patterned duck was not called a 'Grey Duck' as Carl Linnaeus allocated that to the Grey duck (Anas superciliosa superciliosa), a critically endangered species in New Zealand. FAB.