Photograph 1: Some sort of Thrush or Pipit, a Fieldfare?
Photograph 2: A Great or Lesser Black Backed Gull, cormorant is there for size comparison.
Photograph 3: A Raven, I think. There were reports of Ravens all around the Reserve.
Photograph 4: A bit bigger than a finch, I have no idea what it is.
Photograph 5: This bird was seen on an island full of Sandwich Terns. I think it could be a Black Tern. (I'm talking about the bird behind the sandwich tern).
Apologies for the bad, blurry shots.
Check out my other identification threads.