English Sparrow (code name: Victor)

The male Sparrow, whom we named Victor, has returned.
We knew he would as the male sparrow bonds to his last nesting site.
Last year a Black-capped Chickadee family were murdered by Victor and his mate (we called her Victress).
I must say the Sparrows' crime elicited a strong passive aggressive response in me.
I narrowed the birdhouse opening with a large steel washer to the specified size that admits Chickadees, but excludes Sparrows.
Victor tried to gain access today, but failed due to the "Steel Door".
Kathy and I provided another suitable Sparrow nest site nearby.
I wonder how flexible is Victor Sparrow in his nesting behavior.
If the Black-capped Chickadees come back to this birdhouse our plan for achieving "Tweety-Bird Détente" will be a complete success.