Hi all.
Some new details.
Me and Matt Bruce went back to relocate the bird last night. And very early on in the roost, I picked up on an obvious Ring-billed hybrid. As described, it was almost the size of a LBBG, with a very dark, slateish coloured back, and most significantly, very dark head streaking, creating almost a hooded effect!
This bird was without a doubt a hybrid, but I am not totally convinced the same bird was involved! First of all the size was well off compared to the bird we had Saturday. Saturdays bird was much smaller (significantly so!). The head streaking in my opinion didn't at any point reach quite as dark and extensive as last nights bird, and I'm not totally convinced the mantle was quite that dark (however still noticeably darker). The eye also seemed noticeably darker, rather than the very bright pale eye that we observed Saturday. Unfortunately the bird was not seen/ photographed while stretching its wings (an easy way to prove it to be the same bird), and the views were slightly more distant last night.
MB