We have had a family of Tawny owls in our garden after building a nesting box last year. We have seen both the adults and at least one of the babies (which appeared almost full grown but without full feathers) on numerous occasions, during the daytime too. They seemed quite active during the day which surprised us and seem to have been chased a lot by a group of blackbirds when they were out. One seek ago, all went completely quiet and we have not seen of heard them at all since then. Unsure if something has happened to them. We have seen quite a large fox in our garden too...any ideas?
Most likely scenario is that they have just moved on. Once out of the nest they don't return so home is in whatever tree they choose for the night. As the Owlets lose the down and gain their full flight feathers they become much more mobile . Well done on the success of the box and hopefully they will return next year for you.