At first I thought this was a mallard, but on further consideration I’m not at all sure that it is. I seems smaller and with a a more “pointy” bill than the mallards I’m familiar with. The coloration also seems different.
After browsing through a lot of images I’m unable to discover what it is at this point. I’ll keep trying.
Don’t you think it looks a little annoyed?
Taken with a Sony Alpha 500 and Minolta 100-200mm f4.5 AF.