Volatile bird numbers

This web page reproduces and augments the graphic in the current issue of Birds magazine, illustrating the decline of some of our most common bird species. However, the simple overall figures must mask local variations. In particular, there has been no shortage of sparrows round here and it has been a good year so far for blackbirds (like a recent visitor, left). It seems to me that the conservancy bodies in England should look at what has changed there as compared with South Wales, say. My own theory is that there are fewer wild places producing insect prey and nest sites.