Ian, I have been listening to a Marsh Tit singing at the Carved Arch end of the boardwalk for a couple of weeks but there has been a lot of 'management' going on which has included demolishing a rotten stump or two and considerable opening up of the damp carr. It is where I also hear and see willow tits so could have been either! I watched a willow tit attacking a rotten tree stump in my garden with great ferocity, not sure if it was making a hole or finding bugs because the stump disintegrated before I found out! I had to cut down some skinny alders so tied the trunks to living trees to rot in situ which they have providing food for the Great Spots, Nuthatches and tits judging by the excavations in them!
The Green Woodie has been a resident in the lower Berwyn valley for a number of years.