I honestly can't put your total up to 38 on the basis of that list. Number 28 has a question mark on it which automatically means it doesn't count. Some of the ducks are most likely not wild birds as noted by @lintworm and @Maguari. Then there are ducks which you simply wouldn't know if they were genuine wild ones or captive ones (as also noted by Maguari). And you reckon you saw multiple Little Gulls which is just not likely.I was certain about the lesser black-backs and the little gulls. Almost sure about the greater black-backs and the others were more doubtful, although I did have a good look at their legs and beaks especially.
The doves were a surprise for me as well and I wasn't quite sure about it.
When I was researching after this, I did come across these pages and was wondering whether any of the introduced species would count. So thanks for clarifying. I gues that means the list is reduced to:
28. Barnacle goose, Branta leucopsis?
29. Tufted duck, Aythya fuligula
30. Common pochard, Aythya ferina
31. Gadwall, Mareca strepera
32. Common shelduck, Tadorna tadorna
33. Little grebe, Tachybaptus ruficollis
34. Common moorhen, Gallinula chloropus
35. Lesser black-backed gull, Larus fuscus
36. Red crested pochard, Netta rufina
37. Great black-backed gull, Larus marinus
38. Little gull, Hydrocoloeus minutus
Still a productive walk
Of the list above the only ones which you could say were certainly wild birds are the grebe and moorhen, and the lesser and greater black-back gulls are probably correct (although for the last one you say you are only "almost sure about...").
