Geograph - photograph every grid square

The Squirrel Hut in the grounds of Kielder Castle gives the opportunity for bird watching and if you are lucky you may see a red squirrel. We spent half an hour there and didn't see squirrels. We did see blue tits, coal tits, long tailed tits, nuthatches and greater spotted woodpeckers. There is a large feeder hanging immediately outside one of the windows, which were unfortunately grubby so my closeups of blue tits and nuthatches are disappointing and I haven't submitted any here. There are 2 or 3 hatches which open (one used for this photo), but with noisy children coming and going the birds were scared off when the hatches were open.