Robin responses to death?

Although I do think the female robin has started a new nest, she has still been in the garden occasionally.

But one reason has been to chase away another robin. She pursued this other robin with much aggression and the other one was screaming. I think that the other robin is the one that I saw looking bedraggled on the day the babies died. For a couple of mornings, I saw it - and it would hop around on the ground, hiding in the vegetation or in the gap between the conservatory and a low wall. It could fly, but didn't seem to want to. It was also very hungry and would take food from very close to me and stayed quite near. I don't know what to make of all this.

Meanwhile, the male robin has quite a few times looked at the nest and then sung very sadly near it. I have a sense for the emotional tone of their songs and on these occasions it were truly as though he were singing a requiem.

He is spending more time around me than he used to. Again, I don't know what to make of it.