"Shooting at this time of year mimics their natural winter mortality," he explained. "But you are trying to modify their behaviour, not shoot them all. That means you want them to see what you are doing."
By combining shooting with a signal such as a rocket, "you can teach them what a warning is", he added.
As to planting a sacrificial crop such as their preferred clover in the field margins, "there's no science on this, but I expect it would just attract more birds", he said.
Although repellent sprays are available, these could taint the plants and "there's no point if it costs you more than you gain in crop", Baxter added. However, high wiring and netting have been found to repel wood pigeons at sites such as sewage works, he pointed out.