This is the state of play after three weeks. It has been an eventful week with a serious take over bid from a pair of tree sparrows last Tuesday and Wednesday. One tree sparrow was in the box looking round on at least two occasions but the blue tits are still in possession. I know one shouldn't take sides in this situation but I am pleased the blue tits won. There are tree sparrows in at least half a dozen other boxes.
The nest will be top right as we look at it and the female blue tit is in and out of the box very frequently, sorting out the material and often not bringing in anything new. Sometimes she takes bits of moss or straw out again. The nest space still has to be lined - probably with moss and feathers. She doesn't roost in the nest at present and usually won't do so until more or less all the eggs have been laid.
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