Rabbit revealed
For some time plants in the window box have been somewhat bitten down. Mainly it seems to be the leaves of the white clover that disappear, but something has chomped at one of the sallow bushes.
At first I discounted rabbits as it seemed much too difficult for these animals to climb up onto the wire crates that keep the top of the window box up to about waist height.
I have, however, caught the culprit in the act and it is indeed one of our bolder lawn rabbits. This is one record I had not really expected - I hope this bold Brer does not feel inclined to make a burrow.
I am quite happy to let the creature have as much of the clover as it wants and we will have to see about the long term effect. Meanwhile I reckon I have one of the few window boxes in the world that boasts a wild rabbit visitor.