After its clash with the glass, the sparrowhawk flew a yard or so and perched, initially on my privet hedge, and then on the edge of next door's conservatory roof, posing rather nicely for a couple of pictures.
I think that, by clicking on the photos, you will get a larger version of them.
This pose reminds me of those emperor and king penguins in the Antarctic, the males shuffling around with the egg balanced on their feet, Very upright with the breast feathers allowed to droop down to warm the egg. After less than a minute the bird flew off again, giving me a blurred and unusable third photograph as it did so. The bird visits the garden daily now, but I doubt I will get much better photos, unless I catch it in an action shot.