Oh, I recommend that you do not just "leave him out at night".
Someone left their noisy rooster out at a park next door to me and he was mean enough to stay alive (probably scared all the coons and coyotes away). Then, he crowed all night and all day, driving all of the neighbors crazy. Finally, three boys from the church made up a hunting team and made traps ... it was still another couple of days until suddenly the air was silent again.
Plus, I don't believe it is very "humane" ... how terrifying for the bird to be removed from the flock and then hunted to death.
good luck...