Nature's way of managing ecosystem
Every being alive needs energy for survival and that energy is obtained from food. Different beings rely on different sources for food. Most of them obtain food by eating other beings. Nature has made a food chain or a food web to be precise to make every being meet their need of food. And this method of transfer of energy is the basis of life. The beings which obtain food by hunting others are termed as predators and the ones which are being hunted are preys. Predator vs prey
Though the nature has
made this system to maintain the ecosystem, the abilities blessed to both the predators (to hunt) and the prey (to defend themselves) are equal. One of the attributes that preys have for defense is fear of predators. Because it is what keeps them aware of their surroundings to save their life…And humans have learned to use this fear to their advantage.
Scare away the pests
Pests are hard to turn out. They are stubborn and resilient and difficult to be shown the door. As such people come up with different methods to flee them away. While some use pesticides to kill them straight away, some others might be looking to avoid their entry. One option that seems reasonable enough to be used in this case is scaring them away.
Plastic owl vs pigeons
Why not use plastic owls to scare away the pigeons and keep them from your property. After all, the fear of predators has the same effect on the preys as the predators themselves. And though this method is extremely useful in some cases (such as keeping away rodents by using dog's voice) it does not work well with pigeons. They overcome this obstacle.
Why plastic owls don't work?
Owls prey on pigeons. And pigeons are really smart birds. They are afraid of owls as a result. But they have great eyes that can see much more vividly than our own and as I said they are smart. They very easily get to know the difference between a real owl and a fake one. So the presence of a plastic owl doesn't matter in the case of pigeons. But people get lured by this idea as this seems to be a very cheap, convenient and effective option. It is more of a joke than an idea and people shouldn't even consider trying it.