Aegithalos caudatus
The long-tailed tit is easily recognisable with its distinctive colouring, a tail that is bigger than its body, and undulating flight. Gregarious and noisy residents, long-tailed tits are most usually noticed in small, excitable flocks of about 20 birds. Like most tits, they rove the woods and hedgerows, but are also seen on heaths and commons with suitable bushes.
(Info from www.rspb.org.uk)