Aww. I thought for a moment you were going to test us with a tricky spot the difference competition...
Now, apologies that I haven't got a clearer photo but I've had to take a faraway pic and crop, and the image starts losing definition with every crop, but I think I saw a baby bluetit -- and that seems very odd for January. Any bird experts around to enlighten me?
A spot the "baby" competition...bigger
more spot the birds: better one of the "baby"
Of course, it could be just an adult fluffing itself up on a freezing cold day, but none of the other bluetits were fluffed up (as you can see by the "parent" in the picture) and the feathers seemed very grey to me.