It
starts with Barney, who has been feeding the chicks as usual,
suddenly looking over shoulder.
Clearly he has heard something unusual.
The chicks haven't realised that anything is amiss and are clamouring for more food as usual.
A
couple of seconds later and they've got the message. Presumably he has
made a warning call that is recognised instinctively.
Whatever
it is cannot be too dreadful as Barney next goes to the entrance hole to
look out. I hope he wouldn't do that if it was a woodpecker!
What
he sees makes him adopt a fierce protective stance. So what was
it? This year we can tell, thanks to the external camera!
It
was only a great tit paying a visit. A competitor but not a predator!
You can see Barney looking up at where the great tit is standing.
The
great tit moves off and Barney is emboldened enough to come out of the nest
box a bit. One look at his face would put anything off!
Finally
he comes right out, and although we cannot hear him he is undoubtedly
telling the great tit where to go!
When
Fluffy next comes in, the chicks are still cowering down in the nest
cup. It will take quite a lot of cajoling to get them back to normal.