I am now wondering how many different Great Tits have been visiting the nestbox. A Great Tit had settled down for the third night running and I went to prepare a meal. Later I glanced at the monitor and saw the most almighty squabble going on in the box. At first I thought maybe a Blue Tit had unwisely gone in but it soon became obvious they were both Great Tits. It was a really vicious winner takes all battle with feathers flying everywhere. After a short while one decided it had no chance of taking possession and managed to escape.
This still was taken from the video a while after the victor had settled down again. What was a bare box is now lined with feathers.
I have also uploaded to my Flickr account one still of the birds fighting which can be found by clicking on 'Go to Midmarsh John's photostream' in the Flickr widget near the bottom right of this page.
5 hours ago