Does Bony have a brother

Went over Barking Bay today to try to practice a bit of digiscoping, as yesterday i had a Knot in summer plumage in the bay but couldn't I.D it till i got home as it was too far out to get any detail or colour in my bins. The photo's i took yesterday were actually crap as well a fuzzy knot and a blurry sand martin

When i arrived i didn't intend going too far from the Riverside centre just wanted to try some digiscoping.
As i was setting up 2 guys came past who had been down by the cemex jetty and said that the Bonapartes gull was there so i thought i might as well go and  try to find it, as it now had a mottled head and i wondered if i could  pick it  out for myself as i am rubbish with gulls (most other species too). i had an image in my mind of what it was like last Saturday and managed to find it as it didn't really look to different. . Took loads of dodgy pics and of i went. Later when looking at the photo's at home i noticed how prominant the black spot is compared to Richard Bonsers pictures from yesterday. Could be just the dodgy pics or amazingly there could be 2 birds. l could also have took photo's of the wrong bird half the time. Also had my 1st House martin of the year.