Add Three, Subtract One
Whoops, looks like I counted lesser black-backed gull twice. I thought one of them was a herring gull, I think. Fortunately, there's a genuine herring gull below.
I got a robin photo this time.

And I added a long-tailed tit (in a very blurry photo, I'm afraid).

And a juvenile herring gull.

I also saw but failed to photograph a wren.
Alas, this shoveller was in Southwark Park, the wrong side of Lower Road, so I can't count it unless it flies a couple of hundred yards to the east.

So the score is now 33 -- 31 birds (all photographed except the wren) and two mammals (fox not photographed).
I got a robin photo this time.

And I added a long-tailed tit (in a very blurry photo, I'm afraid).

And a juvenile herring gull.

I also saw but failed to photograph a wren.
Alas, this shoveller was in Southwark Park, the wrong side of Lower Road, so I can't count it unless it flies a couple of hundred yards to the east.

So the score is now 33 -- 31 birds (all photographed except the wren) and two mammals (fox not photographed).