If we had done our 'big garden birdwatch survey' at 10am on Sunday instead of 3pm on Saturday then there would have been different results - for a start there would have been at least 10 goldfinches in the garden and we would have recorded two robins:
These are the first robins to visit the garden for a long time. Interestingly, they are fiercely territorial, yet these two seemed to tolerate each other. Unfortunately male and female robins look identical, so it's not possible to tell if this is a potential breeding pair or if they were just migrants stopping off.
Apparently, robins can't visually identify each others gender either and the only way a male knows another robin is a female is through it's response to a territorial display.