BGBW - no sparrows!

Just completed BGBW - saw just one sparrow! Almost a complete collapse compared with previous years when they've easily reached double figures in our garden. Put out a variety of food and titbits to try and tempt them but no show! Had a few visits from a male Sparrowhawk a couple of weeks ago and that seems to have really spooked them! (Or could it be the relatively mild winter we've had so far in South Wales?) Greenfinch also well down but that seems to be following a national trend. Fewer Robins as well - just one when I would have expected to see three or four throughout the winter. Thank goodness for those great 'survivors' Blue and Great Tits! Plenty of them year-in, year out!