In my article of 26 February 2010 entitled Building for the birds [display], I described my construction of a nesting box for mésanges (common tits).
A couple of weeks ago, when my ex-neighbor Bob caught sight of this object attached to a thick branch of one of my linden trees, he immediately started to make fun of it, claiming that no self-respecting bird would ever decide to build a nest in such an artificial contraption. Bob was particularly troubled by the small interior balcony, saying that the parents would be afraid that their babies would climb through the hole and fall to their death. I tried to convince him that experts point out that this kind of balcony is a luxury that is greatly appreciated by the birds when they enter or leave the box. Apparently it gives them a place to rest for a second or so while they're summing up the situation and deciding what to do next.
Over the last couple of days, I've noticed that a male mésange has been flitting around the box in a regular pattern, as if he were standing guard over it. He can be seen in the background of the above photo. This afternoon, I finally discovered that he was periodically entering and leaving the box.
In the above photo, he is clinging to the edge of the circular hole and taking a rapid look inside to make sure that everything's OK. (The green haze in these photos is caused by out-of-focus leaves on branches moving in the breeze.) I imagine that, down at the bottom of the box, his female companion is already nesting.
Bob was finally interested to see that a couple of birds have accepted this abode. I explained to him that I had deliberately installed the box at a certain distance from the branch in order to prevent small rodents from trying to enter the bird house and eat the eggs.