I heard and saw a bird singing this morning, and can't identify it. Brown and possibly some sort of warbler, singing and then getting a reply from another one further away. It was sitting on a branch in a scrubby ditch by the side of a field, rural home counties. I've been online and listened to a few clips but can't find this one. It went (as best as I can write down!):
Twiddle-dee, twiddle-dee, twiddle-dee, twiddle-dee ........... and again, then a pause while it listened to its friend. Then repeated several times.
Any ideas?