There where about twenty of these moths sheltering in a bird hide. As soon as light was let in they crawled into the the dark corners.
No interactions present.
As you say Gary, not possible to be sure which species it is without seeing the underside of the hindwings.
Entomologist and biological recorder
To my eye the upperside markings are suggestive of Copper Underwing and not Svenssons (the zig zag basal cross line seems to have all the zigs the same depth). But like you (and Martin) I'd not be prepared to go beyond Amphipyra sp. without seeing the hindwing.
Lat/Lng: 53.131530010532, -0.14908790588379
OS grid ref: TF239609