Nest box news

14-21 February is National Nest Box Week.  It seems more like two half weeks to me but it is a good time to put up a new nest box.  I have made and put up several new ones recently and I cleaned out all my old boxes just before New Year.  What was interesting was to see how many had been used by tree sparrows.  Before the sparrows arrived in the garden in 2012 most of the boxes were used by blue tits, with occasional great tits, robins, wrens, spotted flycatchers, stock doves, starlings etc.  Last year nine boxes were used by tree sparrows.  When you think they have two or three broods a year and there were others nesting in holes in trees that is quite a lot of new tree sparrows.  Another two boxes had been used by blue tits, one by great tits, in two cases I couldn't be sure what had been in and six were unused. That makes 70% occupancy and 64% of that was by tree sparrows.

It is easy to tell when sparrows have been in a box because of the way they build their nests.  Here are two typical examples.  The box is almost full of grass and feathers with an arch or dome of material over the top.

It was this that made life so difficult when trying to video the sparrows in my camera box last year. This was the box when I came to clear it out.

I had two triple terrace boxes specifically for the tree sparrows.  When I looked inside one had all three boxes used

and the other was empty.  However it also had a leaky roof and the remains of a dead adult sparrow in the left hand box.  Maybe the corpse and the damp caused the birds to move elsewhere.  I have cut this one down to two individual boxes and replaced the roofs.

This is what the remains of a blue tit nest look like.  The nest was mostly made of moss.

I have been experimenting a bit with the dimensions and entrances of some of the new boxes, hoping to attract other birds like coal tits or treecreepers.

Others are more traditional.

Because the sparrows kept blocking the view in the camera box I have replaced the entrance plate with one with a 25mm hole which should mean I'll get blue tits in the box this year.  In the past couple of days one prospective tenant has been in to have look around.

I 'll try to keep a closer eye on who is in which box in the spring (I said that last year).  I'll also post regular updates if the camera box is occupied again (it has been every year since I put it up in 2009).  You can find more information about National Nest Box Week from the BTO here.