That was surreal.
Bins have been lying next to the window all day - didn't bother putting them back following a bit of garden birding this morning. I glanced out of the window and saw something silhouetted on the roof opposite. "Looks a bit pigeon shaped" I thought, but something at the back of my mind was saying "the hell it is", so I picked up the bins for a quick look and at that very moment, the bird started moving. Managed to get a fix on it just as it spread its wings and started to fly off.
It was not a pigeon.
In fact, it looked quite female-Kestrel like. This would be consistent with my initial impression of size.
If I consider my Garden, as a site, to be anything I can see from my back window (and I do), that's a rather spiffy garden tick.
Never underestimate the power of the subconscious.