There are about 20 nest boxes scattered around various locations at Exbury. Three of us spent a morning cleaning them out. This is a seasonal job as used boxes can contain parasites, which have an adverse effect on breeding success the following season.  It’s also interesting to see what has gone on inside the box.

The first batch of boxes was put up on oak trees on Jubilee Hill and are the least successful; a possible reason might be the lack of undergrowth in the area, leading to reduced numbers of insects. This year one box contained an unhatched clutch of blue tit’s eggs (photo), another had had its entrance hole greatly enlarged, probably by a squirrel (photo); several had been claimed by spiders as a cosy winter home (photo), and although others contained some nesting material there was no evidence that breeding had occurred.

Elsewhere on the property there was greater success: while one box contained the remains of three great tit chicks (others could have fledged) there were nine with well-formed nests, including one in a box which had split completely down the front (photo). Some of the boxes are open-fronted and too high on the tree for easy checking, and one has been taken over by Tree Bumblebee (Bombus hypnorum).

It’s always interesting to open a nest box and see what it contains – a bit like opening a stocking on Christmas morning: it can be full of surprises!