We are not sure whether the bluetit is aware that the great tit is inside the box or not. I suspect not as it did not approach the box cautiously.
He soon discovered his mistake and immediately flew off!
And this is why. The great tit's wing posture is a display threat - you keep out!
It soon calms down once the bluetit has departed.
A couple of seconds later it has a look out. Presumably to see whether there is any sign of the bluetit.
Chirruping a victory song perhaps?
Forty minutes later the bluetit returns - this time for a rather more careful look!
Fifty minutes later, the great tit is still there and again it seems to be saying something
This time there is another reason for its behaviour. This and the previous picture were recorded at the same time. The absence of any wing display in either bird makes us think these birds may be partners. Just as well if we want to have some chicks this year!
Which bird is the male and which the female is not clear at this stage. It is normally the male's role to find a possible nest site and introduce the female to it, so perhaps the bird outside is the female. We will find out which is which in due course as only the female builds the nest.
The great tit spent most of the afternoon inside the box and by 10 past 5 it looked as though it was settling down for the night. As a result, we decided to switch off the inside lights (and therefore stop recording) and see whether it would stay and roost for the night.
However, a couple of minutes later, it emerged from the box and went to roost elsewhere.