2 PAIRS OF BLACKBIRDS NESTING IN SAME GARDEN

Observation - 2 PAIRS OF BLACKBIRDS NESTING IN SAME GARDEN - UK and Ireland. Description: We have TWO pairs of blackbirds in the same hedge in our garden - we are sub-urban, about .5 mile from open country. There does not seem to be any rivalry between the two males and the eggs are hatched in both nests and nestlings are being fed. I post t

We have TWO pairs of blackbirds in the same hedge in our garden - we are sub-urban, about .5 mile from open country. There does not seem to be any rivalry between the two males and the eggs are hatched in both nests and nestlings are being fed. I post this, as I have observed in the past that blackbirds are VERY territorial and do not tolerate rivals easily. Could it be that they feel safe here as we have ONE pair nesting here every year?