These are geese! You probably know that as they are very well known, recognisable birds. I found this pair along the River Don today, and they seemed to be a male Grey Goose (Anser anser, left) paired with what looked like a hybrid female Canada Goose (Branta canadensis). Either way they were both very obliging for this photo!
The word 'goose' was familiar to me... but the word 'goosander' was not, until I saw some today and 'put a face to the name'. Goosander (Mergus merganser) are a waterfowl that appears to be a duck crossed with a grebe. They dive for fish but swim on the surface and bask in the sun on rocks much like a duck. Here is a shot of a pair, the female is on the left. I wasn't able to get that close, but the male's black head is actually iridescent green, a really stunning sight.
Further upstream I came across 4 ducklings, which were all by themselves, no parents in sight. From their beautiful faces and pointed bills, I thought they must be Goosander, but I'm not sure until I check their identity with my local expert! Whichever species they are, they certainly are very cute! More coming very soon!