The black blob on the bottom of the nest box is a fresh barn owl pellet and the first sign that an owl is around and might be interested in settling in.
A search back through the nest box camera’s saved clips reveals all. The barn owl has been visiting for a couple of days and even rested all day on Friday. We don’t know if it’s male or female, or if it is one of the adults from this year (it is unlikely to be any of the fledglings). We can’t see if it is ringed yet either. Will let you know more when we do.
Almost exactly to the day a barn owl starts to visit the nest box. It was 1 October when we first spotted one last year https://tiptonscroft.org.uk/blog/new-tenant/.