Nest boxes

National nest box week starts each year on St Valentine's Day so it is already long gone.  I had cleared my boxes of the old nests before then and birds are now busy building new ones.  Last year I had 26 boxes.  Checking them earlier this year I found 10 were empty and three nests had been started but not completed (two tits and one tree sparrow). Another two nests were abandoned with five eggs and nine eggs respectively.  Both were blue tit nests and I suspect one parent from each at least had been taken by the sparrowhawk.  This is the nest from the box with nine eggs.

I read recently that cuttlefish can pass the Stanford Marshmallow Test, that is they can forgo instant gratification for a delayed greater reward.  Obviously the same is not true of sparrowhawks as he would have been better off letting the parents raise their young and then eating the fledglings, but perhaps he was just hungry.

Ten boxes looked as though they had seen successful nesting - four tree sparrow, one robin, three blue tit and two great tit.  And the final box had been occupied by wasps.  I remember watching them last summer, and noticing that the wasps were coming out of the back as well.  Here is the wasp nest.

And when I removed it I found they had chewed away the back of the box.  I have rebuilt it with a new back.

I would have thought this box was too small for a wasp nest.  It may be that they moved on to a larger nest nearby (as hornets do, for instance) and certainly the nest was abandoned by mid summer.

After noticing lots of fights over ownership of a tree sparrow box opposite my front door I made two more and put them up close by.  Within minutes both had been claimed by chirruping sparrows, proving perhaps that there is a local housing shortage.  If both end up being used I'll add a few more to this group for next year.

Last year was the first time since it was put up 12 years ago that my camera box had no nest in it.  This was particularly disappointing because I had modified it by putting in a sloping false back wall and moving the camera higher so that it can now see the whole of the nest (if there is one) and the entrance hole.

It did attract interest from a tree sparrow last year but has a 25mm hole plate to keep sparrows out and allow in only blue tits.  I have nothing against tree sparrows but the construction of their nest makes it almost impossible for the camera to see what is going on.

This year I again haven't seen any interest in the camera box, so I am not sure what has changed.  It has been cold recently so that may have delayed the start of nest building but the latest start to a blue tit nest in previous years was on 4th April.  I have eventually decided that the blue tits aren't interested (or perhaps the sparrowhawk has eaten them all) so I have put in one of the left-over nests from last year in the hope that it may attract a tree bumblebee, although it may also be too late for that.  If anything happens I'll post it here.