In January 2012 I used some old wooden planks to create a nesting box following these instructions (Danke an den NABU).
I was reading that you need to be patient to have an inhabited nesting box – especially in the first year. The birds are starting to look for the right home sooner than one might think. So, the idea was to put the box up as soon as possible. Normally you should do it in the autumn the year before, but, as usual, I was a bit late for that. My hope were quite low…
It was on the Easter weekend 2012 when I first saw activity around the box. Not being able to observe it 24/7 I was probably missing most of the visits. I now think at this time they either breeding or building up the nest.
It was only when the chicks arrived the activity raised noticeably. At that time you needed little patience to observe the parents arriving with food in their beak. However, they are very sensitive regarding the distance you respect to the nest. Being too close will make one of the parents (I think the male) cry out with warning signals.
This is even making the other one (so probably the female) not entering the box. Unless the chicks cry, they will stay outside. Any noise of the chicks seems to lower their threshold of danger – especially for the female.
The blue tits are very good pilots compared to other birds I observed. They fly, start and land very fast. But I was able to capture some of theirs visits. Here is one example:
When everything was done (mid-June) my curiosity was making me open the box to inspect the nest. Of course, before that, I made sure that there was really no more activity. The nest was really soft and super-light and to my surprise I found that there were still some eggs. This fact made me ask a question gardening.stackexchange. I think, that the box (especially the roof) was not water-proof enough and we had some heavy rain during that period. Maybe the eggs have gotten too cold and thus died.
I put the nest back into the box. I later learned that this might not be a good idea, because it might prevent a new breeding the following year. Well, this was not the case, the following year a European Nuthatch family chose to breed in that box.