PETER THEOBALD says:
I have never come across a problem with collared doves that has not been confined to the areas around grain stores.
They almost never congregate in numbers where they might cause a problem, i.e. on agricultural crops.
That said, when they gather together around grain sheds and farm buildings they can be a real menace.
There is no need for decoys, or even a hide, as collared doves are quite oblivious to humans. That is not to say they offer poor shooting, quite the reverse in fact.
Just station yourself on the flightline as close as is safe, to the buildings, as possible.