Rather unusually no-one managed to identify it. It’s not native to the UK and looks similar to quite a large variety of other species, because it’s a member of the Passeriformes (the perching birds), which is a hugely diverse and numerous group of birds. These factors make identifying the bird tricky, but without the plumage there to provide clues it was a very difficult task.
The plumage would have been a big help here, since the name of this bird is taken largely from a description of the plumage.
As you can probably work out from the photo above, it’s a Long-tailed Glossy Starling Lamprotornis caudatus (Statius Muller, 1776).
These tropical African birds are similar in diet and habits to the European Starling that we see more commonly – they just look a lot prettier.