Pigeons can be a nuisance, or a joy to watch. In some areas people take great joy in feeding the "Pigeons in the Park", while others are frustrated by their efforts to try to rid an area of them. There are over 300 species of pigeons in the world, with 11 of them living in the US. (Canada has 3 species of pigeons) They exist all over the world except for the Arctic, and Antarctic areas, and a few isolated islands in the oceans. They are swift, powerful flyers that can cover long distances. They have an unusual way to drink. Unlike other birds that tip their heads back to swallow what they've sipped up, pigeons dip their beaks into the water, and suck it up like a straw. Those that survive the first few months of life, will live an average of 3 to 5 years. They lay 2 small, white eggs that will hatch 17 or 18 days later. They have the ability to re-mate and re-nest many times throughout the year. The squab, or young pigeons used to be a delicacy in restaurants, but only privately raised pigeons are used for food anymore. The wild varieties carry Histoplasmosis and Psittacosis diseases, which affect the lungs and other organs of humans, and so, they should not be used for food.
Their habit of defecating all over the place is their biggest nuisance characteristic. The droppings are caustic and cause damage to marble, stone, and mortar. The droppings and nesting materials often clog up roof drains, and fans, motors, and vents on rooftop heating and cooling units. They are not a native bird to the US, and it is largely for that reason that they are one of only a few birds that ISN'T protected by any sort of laws, treaties, or seasons. Although "doves" fall into the "pigeon" cateragory, they ARE protected birds, and one should check state and local ordinances before doing anything to try to effect their numbers. Mourning doves USED to be the number one game bird hunted in the US, but I'm unsure of their status, now.
The methods for eradicating pigeons are varied. They can NOT be captured and relocated, for they will find their way back from hundreds, if not thousands of miles away. Rurally they can be shot, but you'll find that they quickly become wary of you, and will even recognize the vehicle you drive up in. There are poisons that you can buy that are put on wires and landing areas, and then absorbed through the feet; but they're not "target specific", and will kill ANY bird that lands and has contact with it. Rat traps, similar to snap-type mousetraps are successful, but not always the most humane method. The best luck I've personally had, is to work on their habitat. We used to have an estimated 1800 to 2000 pigeons in our little downtown area (About 12 square city blocks), and the Police had been "shooting" them for probably 50 to 75 years. I tried that method, but soon found I couldn't get near them. Then I started going up on rooftops, and into empty buildings. I screened over openings, boarded up entrance holes, destroyed nests, and generally made our uptown area a place that WASN'T attractive for them. I sometimes added a "stuffed animal" to the area, which scared them greatly. The animals alone only work for 5 to 7 days, but couple them with areas that they can no longer access, and they just give up and go elsewhere.
If you have them landing in a small yard area, or roof of your house or garage; you can scare them off by hanging strips of tinfoil from the trees and upper structures.
