Twenty five seconds later, he's back. (Or is it another bird? It's difficult to tell this early in the season.)
Again, no messing about on the box's entrance hole - he goes straight in.
This looks like the same bird as last time.
But he's still a bit anxious.
He pops up to the hole to look outside.
Here he is as picked up by the outside camera.
Back into the box again.
Suddenly, the outside bird is back.
She jumps up to the roof ...
... and then returns to the entrance hole.
All of a sudden, the female disappears! After a short while the male realises that she has gone and comes to the hole to look for her.
The male looking out of the nest box hole.
Finally, he realises she has gone.
So he goes too!
So having started by warning the female off, he ends by appearing to be disappointed that she has gone.
You can't satisfy some males!
The male leaving the box.
Still, it looks as though we may have a pair forming here - even if they don't always appear to recognise each other! Let's hope this leads to something worthwhile.