Little owls .... and then there were two

This is a pair of little owls which we think (hope) are nesting in the tree just outside out garden. We have made them an owl box (which last year was nested in by starlings ) which is just next to the tree in question . We thought they might be using it but now we're not so sure - the problem being that we can't actually see the box from the house as it is on the outside of a wall that looks over the fields not our garden. However they are in the tree so often we think they may be using a hole in the base of it if not the box. Anyway they are beautiful little owls especially when the sun catches them sitting in the tree first thing in the morning - sadly my photographic skills or camera don't do them justice