Location: UK East Midlands, suburban garden. Bird: possible marsh tits, something in that size range with a black cap. Time: late July.
Two similar-looking birds were observed making high-pitched, very loud calls while "dancing" (wobbling from side to side) perched on a telephone/telegraph wire. If disturbed they would move to another wire and carry on as before.
I have a few related questions. First off, is this courting behaviour? And if so, why are these birds courting when small British bird species do not nest after July?
Second, is this kind of shaking "dance" and call combo diagnostic for a particular species?