This male Blackbird is fairly distinctive because it a has a white chin patch. I think that many male Blackbirds have odd feathers that aren't black making them identifiable.
I woke up early this morning, about 4.30am. The dawn chorus was already in full swing and was dominated by Blackbirds. As happened last year the garden seem to be at the junction of three territories. This afternoon I watch three pairs collecting food, all on the lawn in the main garden. Occasionally two of the males would have a chase, but in general they seemed to treat the area as neutral ground. I know some birds have separate territories which they defend for breeding and other areas that are communal feeding areas but I thought that Blackbirds defended a total territory. Perhaps they are tolerant of each other because it is borderline for all three territories.