Basking on a log last summer. I have heard of these animals invading. These are the first I have seen.
No interactions present.
The one I thought was Trachemys scripta was the left-hand one.
The shell shape on the central one seems more squashed and the shell of the right-hand one has a pointy 'tail'. Not my area of expertise at all so these could just be variations (they didn't seem to match the silhouettes for any other species shown in the 2011 London Naturalist).
I'm pretty sure the two on the left are both Trachemys scripta elegans from the head markings. Wouldn't like to say for the other one as the photo isn't so clear.
Lat/Lng: 51.4183, -0.065
OS grid ref: TQ346705