I had 3 robins in the garden today right next to each other and I have a feeling one was a male and the other two were females vying for his attention. I know that one of the robins is building a nest in the ivy on our house as I've seen what I think may be a female hovering close and then diving into the ivy when she thought I wasn't looking! I saw what I thought was a male with a leaf in his beak hanging about round the corner which is where they have nested before - on top of the nest box rather than in it! I think they feel quite safe as Steve works on the drive right beside them and so they know cats won't be visiting while he's there. I shall be so pleased if we have 2 robin nests this year. They were eyeing each other.
Love robins, we don't get them here in Oz, but when we lived in the UK a pair of robins decided to nest in our shed so we couldn't close the door for weeks until they had flown the nest.