Seen singly, I can't distinguish them by sight, it is their behaviour that sets them apart. Scruff is far more confident, and always to the fore. She knows I can provide food and will sit and wait till I throw some towards her, and she will zoom down to grab it and fly away. Scruff will search me out in the garden, and call out, perched right next to me. He will also sit outside the windows of whichever room I am in, waiting for me to go out to hand feed him.
When I took this image, Scruff was over to my right.
