With reference to the hide and photos of mutes and bird remains around the central pillar of the hide I have the following thoughts. The mutes appear to be copious and dropped rather than squirted out, a sparrowhawk, goshawk or buzzard would expel a mute leaving a distinct line of white. A falcon would drop a mute without leaving such a line but l think that a dark central part to droppings would be visible in any of the diurnal raptors; neither do I think that any of the species would be inclined to enter a hide unless possibly a sparrowhawk in hot pursuit of quarry. I am therefore of a mind that the species is probably an owl, the droppings certainly resemble barn owl droppings but I wouldn't rule out another owl species. The only identifiable remains (from photo) looks like a starling wing, it would be quite possible for a barn owl to take a roosting starling. An owl could easily use the hide completely unseen.
