The male is unmistakable with his bright pinkish-red breast and cheeks, grey back, black cap and tail, and bright white rump. The flash of the rump in flight and the sad call note are usually the first signs of bullfinches being present. They feed voraciously of the buds of various trees in spring and were once a 'pest' of fruit crops. Recent declines place it on the Red List. (Info from www.rspb.org.uk)
NB: The copyright for this image was purchased from me by Deluxebase Ltd but they have granted me permission to still use it here on a personal use basis.