Have been puzzling over this bird (middle of picture) visiting my feeders this week. On first glance you think Tree Sparrow then realise the duller grey plumage and begin to re-assign as House Sparrow but the bird is slightly smaller then the others, there is definitely the beginnings of a Chestnut cap and also a slight cheek spot. Dare one call it as a cross?
It must be a female bird I assume, showing some Tree Sparrow characteristics. The possibility is not unknown as in 2004 I caught these two at it in the tree outside my office window. They nested in the House Sparrow terrace immediately below where the shot was taken and laid three eggs but these were abandoned after a few days, probably due to a gale that blew some debris down onto the box.
A BTO nest record was returned for the attempt and the crappy photo published on their forum. Will attempt to get some better shots of the current suspect when daylight eventually returns to Dinnington.