Pigeons are a menace, especially around buildings. They nest in rafters clogging vents; they chip away at insulation; they defecate on everything; and they are just plain nuisances. Owl figurines, cats, noise deterrents and spikes are all used to discourage pigeons from inhabiting, but none are truly effective. To get rid of pigeons completely, you usually have to kill them. Poison is usually the first thought, but if another animal ingests the poison induced pigeon, then they too will die.
Trap the pigeons in one common area such as a baited cage trap or a large lofty building, such as a barn.
Dispose of the pigeons caught in smaller cage traps however you like. For instance, you can set them free elsewhere or shoot them with a BB gun. Stronger guns can be used, but a BB gun is sufficient.
Hunt the pigeons that you have trapped in the barn using your BB gun. The pigeons will get smart once you start shooting, so it may take more than one person shooting, or more than one time hunting the pigeons trapped in the building. BB guns are best when shooting inside because they do not cause much damage.
Hire a falconer, someone who trains raptor birds to hunt on command. This is an alternative to hunting the pigeons with a BB gun. With the birds trapped in an enclosure, the raptor can hunt the pigeons. Raptors can scare the pigeons away or fatally kill them.
Put up bird spikes, owl figurines or use noise deterrents once you have got rid of the pigeons to deter other pigeons from nesting in your area.
When shooting the pigeons, always aim the guns up.