Birds on wires - should 11kV lines be vertically stacked or horizontal?

I saw     this article    where birds on an HV line were causing the interrupters to fire,

And I wondered if, as well as what happens to the cooked birds, if this would be better or worse if the wires were vertically stacked instead of horizontally - round here on some very exposed hillsides with wind problems, the lines are vertically stacked to prevent them swaying into each other. Equally, the problem may be birds by-passing the insulators rather than wire to wire contact.